ALBERT

Description: This software package calculates postburial production for samples with complex time-depth burial histories. The code was developed for Ott et al. 2022. Production rates are calculated using CRONUScalc v2.1 (Marrero et al. 2016). The current version is developed for 10Be and 36Cl but can easily be expanded to any nuclide within CRONUS. To run the code, you need to input your sample data through excel spreadsheets. The nomenclature follows the CRONUScalc input for the nuclide samples. An additional excel file with the parameters of the burial models (time-depth constraints) needs to be provided. CRONUScalc can be downloaded here https://bitbucket.org/cronusearth/cronus-calc/src/v2.1 The InputData folder contains all data from Ott et al. (2022) and can be used as an example of the input formatting. The postburial_prod.m script illustrates how to use the subroutines. Please, report bugs to richard.ott1900@gmail.com

Description: We provide a globally distributed compilation of published surface temperature proxies for eight Cenozoic time periods that cover the range of paleoclimate states. The proxies have both a marine and terrestrial provenance and are compared to the annual temperature of the same location today. This data is then used to quantify long-term temperature changes on zonal and global levels. When coupled with recent estimates of atmospheric CO2 concentration, temperature data constrains the sensitivity of Earth's climate system to perturbation of the radiative balance, with possible implications for the future response to anthropogenic forcing. The dataset consists of an excel file with eight sheets for the eight selected timeslices, namely, • mid-Pliocene (3,0 - 3,3 Ma) • late Miocene (7,2 - 11,6 Ma) • mid-Miocene (14,7 - 17,0 Ma) • early Miocene (20,3 - 23,0 Ma) • early Oligocene (27,8 - 33,9 Ma) • late Eocene (33,9 - 37,8 Ma) • middle Eocene (42 - 46 Ma) • early Eocene (48 - 55 Ma)

Description: The DFG Priority Program 1803 “EarthShape” (www.earthshape.net) investigates Earth surface shaping by biota. As part of this project, we present Light Detection and Ranging (LiDAR) data of land surface areas for the four core research sites of the project. The research sites are located along a latitudinal gradient between ~26 °S and ~38 °S in the Chilean Coastal Cordillera. From north to south, the names of these sites are: National Park Pan de Azúcar; Private Reserve Santa Gracia; National Park La Campana; and National Park Nahuelbuta. The three datasets contain raw 3D point cloud data captured from an airborne LiDAR system, and the following derivative products: a) digital terrain models (DTM, sometimes also referred to as DEM [digital elevation model]) which are (2.5D) raster datasets created by rendering only the LiDAR returns which are assumed to be ground/bare-earth returns and b) digital surface models (DSM) which are also 2.5D raster datasets produced by rendering all the returns from the top of the Earth’s surface, including all objects and structures (e.g. buildings and vegetation). The LiDAR data were acquired in 2008 (southernmost Nahuelbuta [NAB] catchment), 2016 (central La Campana [LC] catchment) and 2020 (central Santa Gracia [SGA] catchment). Except for Nahuelbuta (data already was available from the data provider from a previous project), the flights were carried out as part of the "EarthShape" project. The LiDAR raw data (point cloud/ *.las files) were compressed, merged (as *.laz files) and projected using UTM 19 S (UTM 18 S for the southernmost Nahuelbuta catchment, respectively) and WGS84 as coordinate reference system. A complementary fourth dataset for the northernmost site in the National Park Pan de Azúcar, derived from Uncrewed Aerial Vehicle (UAV) flights and Structure from Motion (SfM) photogrammetry, is expected to be obtained during the first half of 2022 and will be added to the above data set.

Description: Cosmogenic nuclide measurements are commonly biased by weathering within the cosmogenic nuclide production zone. The code package “WeCode” (Weathering Corrections for denudation rates) integrated within the CRONUScalc v2.1 (Marrero et al., 2016) software performs weathering corrections and calculations, as well as offering pixel-by-pixel catchment production rate estimates for alluvial samples. Weathering corrections can be applied for weathering within the regolith or along the regolith-bedrock interface, as is common in carbonate bedrock. The methods for the weathering corrections are described in Ott et al. (2022). Please refer to the README for information on how to use the software. A set of input examples and scripts is provided for illustration. CRONUScalc can be downloaded here https://bitbucket.org/cronusearth/cronus-calc/src/v2.1

Description: The ratio of 18O to 16O in cherts and other chemical sediments has increased by about 15‰ over geological time, but the cause of this increase is debated. Here, we provide a 1D sediment-column model designed to investigate the role of diagenesis, and specifically the heat flow through marine sediments, in setting the chert oxygen isotope ratios. The model simulates the transformation of amorphous silica (opal-A) to crystalline quartz via an intermediate phase by using a silicon mass balance that is driven by the kinetics and thermodynamics of silica phase dissolution and (re)precipitation. The model demonstrates that heat flow through marine sediments influences the rate, and therefore depths, temperatures, and oxygen isotope compositions, at which cherts form. The implication is that because global heat flow from the solid Earth has decreased through geological time, heat flow is an important contributing factor to the long-term trend in chert oxygen isotope composition. The model is provided as a set of Matlab scripts (".m" files) and assorted input datasets provided as standard plain text files. The model is described in full in the manuscript "Chert oxygen isotope ratios are driven by Earth's thermal evolution" by Michael Tatzel, Patrick J. Frings, Marcus Oelze, Daniel Herwartz, Nils K. Lünsdorf, and Michael Wiedenbeck, and in the online Supporting Information associated with the manuscript. Once downloaded and unzipped, the files should be added to the local Matlab search path. The parameters of interest can be changed in the first few lines of 'chertKineticModel.m'. No other files need to be opened or modified. These files have been tested in Matlab R2020a running on Mac OS X 12.2.1 and in Matlab R2022b on Mac OS X 12.6.1.

Description: This data publication is supplementary to the study on headwall erosion rates at Glacier d'Otemma in Switzerland, by Wetterauer et al. (in press). Debris on glacier surfaces stems from steep bedrock hillslopes that tower above the ice, so-called headwalls. Recently, rock walls in high-alpine glacial environments experience increased destabilization due to climate warming. Since supraglacial debris alters the melt behaviour of the ice underneath, increased headwall erosion and debris delivery to glacier surfaces will modify glacial mass balances. Therefore, we expect that the response of glaciers to climate change is likely linked to how headwall erosion responds to climate change. As headwall debris is deposited on the ice surface of valley glaciers it is passively transported downglacier, both supra- and englacially. Where two glaciers join, debris along their margins is merged to form medial moraines. Since medial moraine debris tends to be older downglacier, systematic downglacier-sampling of medial moraine debris and the measurement of in situ-produced cosmogenic 10Be concentrations ([10Be]) hold the potential to assess long-term (>10^2-10^4 yrs) headwall erosion rates through time. However, to obtain the cosmogenic signals of headwall erosion, [10Be] within supraglacial debris need to be corrected for glacial transport time, as cosmogenic nuclides continue to accumulate during exposure and transport. This additional 10Be accumulation during debris transport can be accounted for by simple downglacier debris trajectory modelling. Providing our 10Be dataset together with detailed information on our 1-D modelling approach is the main objective of this data publication. The data is presented as one single xlsx-file with three different tables. A detailed description of the sample processing and the debris trajectory model are provided in the data description file of this data publication. For more information see our study Wetterauer et al. (in press).

Description: The melting relations of the CaCO3 MgCO3 system are investigated and trace element partition coefficient of Li, Na, K, Mn, Fe, Sr, Ba, Pb, Nb, Y and rare earth elements (REEs) between carbonates (Mg-calcite, Ca-magnesite) and dolomitic melt are established from high pressure (6 and 9 GPa) and temperature (1300 1800 ℃) experiments utilizing a rocking multi anvil press. We show that Ca Mg carbonates are stable within the subducting slab beyond ~300 km (9 GPa) but will (partial) melt beneath mid ocean ridges and in upwelling plumes. In contrast to previous studies, we report incongruent melting of carbonates producing a carbonate melt and periclase between 4 and 9 GPa. Partial melting of carbonates produces dolomitic melts whereby the trace element signature largely depends on the Ca/Mg-ratio of the bulk system. For instance, REE will be fractionated by two orders or magnitude between Ca magnesite and dolomitic melt. In contrast, melting of Ca rich carbonates will not lead to a significant REE fractionation. The here published data set includes all chemical analysis (major and trace elment composition) of run products and starting materials. From this data set we obtained the melting relations and partition coefficients reported in Sieber et al. (2020); Sieber et al. (under review).

Description: The geomagnetic main field is vital for live on Earth, as it shields our habitat against the solar wind and cosmic rays. It is generated by the geodynamo in the Earth’s outer core and has a rich dynamic on various timescales. Global models of the field are used to study the interaction of the field and incoming charged particles, but also to infer core dynamics and to feed numerical simulations of the geodynamo. Modern satellite missions, such as the SWARM or the CHAMP mission, support high resolution reconstructions of the global field. From the 19th century on, a global network of magnetic bservatories has been established. It is growing ever since and global models can be constructed from the data it provides. Geomagnetic field models that extend further back in time rely on indirect observations of the field, i.e. thermoremanent records such as burnt clay or volcanic rocks and sediment records from lakes and seas. These indirect records come with (partially very large) uncertainties, introduced by the complex measurement methods and the dating procedure. Focusing on thermoremanent records only, the aim of this thesis is the development of a new modeling strategy for the global geomagnetic field during the Holocene, which takes the uncertainties into account and produces realistic estimates of the reliability of the model. This aim is approached by first considering snapshot models, in order to address the irregular spatial distribution of the records and the non-linear relation of the indirect observations to the field itself. In a Bayesian setting, a modeling algorithm based on Gaussian process egression is developed and applied to binned data. The modeling algorithm is then extended to the temporal domain and expanded to incorporate dating uncertainties. Finally, the algorithm is sequentialized to deal with numerical challenges arising from the size of the Holocene dataset. The central result of this thesis, including all of the aspects mentioned, is a new global geomagnetic field model. It covers the whole Holocene, back until 12000 BCE, and we call it ArchKalmag14k. When considering the uncertainties that are produced together with the model, it is evident that before 6000 BCE the thermoremanent database is not sufficient to support global models. For times more recent, ArchKalmag14k can be used to analyze features of the field under consideration of osterior uncertainties. The algorithm for generating ArchKalmag14k can be applied to different datasets and is provided to the community ss an open source python package.

Description: Das geomagnetische Hauptfeld ist essenziell für das Leben auf der Erde, da es unseren Lebensraum gegen den Sonnenwind und kosmische Strahlung abschirmt. Es wird vom Geodynamo im Erdkern erzeugt und zeigt eine komplexe Dynamik auf unterschiedlichen Zeitskalen. Globale Modelle des Magnetfelds werden zur Studie der Wechselwirkung von einströmenden geladenen Teilchen genutzt, aber auch um Kerndynamiken zu untersuchen und um sie in numerische Simulationen des Geodynamos einzuspeisen. Moderne Satellitenmissionen, wie SWARM und CHAMP, stützen hochauflösende Rekonstruktionen des globalen Felds. Seit dem 19. Jahrhundert wird ein globales Netzwerk von magnetischen Observatorien aufgebaut. Es wächst stetig und globale Modelle können aus den Daten, die es liefert, konstruiert werden. Geomagnetische Feldmodelle, die weiter in der Zeit zurückreichen, basieren auf indirekten Beobachtungen des Felds, d.h. auf thermoremanenten Daten, wie gebrannten Tonen oder vulkanischen Gesteinen, und auf Sedimentdaten aus Seen und Meeren. Diese indirekten Beobachtungen werden mit (teilweise sehr hohen) Unsicherheiten geliefert, die aus den komplexen Datierungs- und Messmethoden resultieren. Ziel dieser Arbeit ist die Entwicklung einer neuen Modellierungsmethode für das globale geomagnetische Feld während des Holozäns, welche die Unsicherheiten berücksichtigt und realistische Schätzungen für die Verlässlichkeit des Modells liefert. Dabei werden lediglich thermoremanente Daten betrachtet. Diesem Ziel wird sich zunächst genähert, indem ein Schnappschuss-Modell konstruiert wird, um die unregelmäßige räumliche Verteilung der Daten und die nichtlineare Beziehung zwischen Daten und Magnetfeld zu untersuchen. In einem Bayesianischen Rahmen wird ein auf Gaussprozessen basierender Algorithmus entwickelt und zunächst auf diskretisierte Daten angewendet. Dieser Algorithmus wird dann um eine zeitabhängige Komponente ergänzt und erweitert, um Datierungsfehler zu berücksichtigen. Zuletzt wird der Algorithmus sequenzialisiert, um mit numerischen Herausforderungen umzugehen, die aufgrund der Größe des Holozän-Datensatzes bestehen. Das zentrale Ergebnis dieser Arbeit, welches alle genannten Aspekte beinhaltet, ist ein neues globales geomagnetisches Feldmodell. Es deckt das gesamte Holozän ab, bis ins Jahr 12000 BCE, und wir nennen es ArchKalmag14k. Bei Betrachtung der Unsicherheiten, die gemeinsam mit dem Modell ermittelt werden, wird deutlich, dass die thermoremanente Datenbasis nicht ausreicht, um globale Modelle vor dem Jahr 6000 BCE zu stützen. Für jüngere Zeiträume kann ArchKalmag14k genutzt werden, um Merkmale des Erdmagnetfelds unter Berücksichtigung der a posteriori Unsicherheiten zu analysieren. Der Algorithmus, mit dem ArchKalmag14k erzeugt wurde, kann auf weitere Datensätze angewendet werden und wird als quelloffenes python-Paket zur Verfügung gestellt.

Description: Major tin (Sn) deposits within the Variscan orogen are closely related to 325–270 Ma postkinematic granites that intruded the metamorphic rocks of the former precollisional accretionary wedge of the Gondwana margin. In the Erzgebirge (Germany), some of these metasedimentary rocks have high Sn contents (locally more than 1000 ppm Sn). We report cassiterite (SnO2) U-Pb ages of 395–365 Ma and high Sn contents in prograde biotite in these metasedimentary rocks. These data demonstrate that Sn was already introduced into these rocks during accretion and prograde metamorphism. Mobilization of Sn from sedimentary source rocks during prograde fluid loss in a subduction-accretion setting represents an important process of pre-enrichment of sedimentary source rocks that upon partial melting may produce Sn-enriched melts. The large-scale metamorphic mobilization of Sn, documented here for the first time, highlights the possible importance of metamorphic Sn enrichment in accretionary complexes, thereby explaining the spatial distribution of major Sn districts within the Variscan orogen.

Description: Floods affect more people than any other natural hazard; thus flood warning and disaster management are of utmost importance. However, the operational hydrological forecasts do not provide information about affected areas and impact but only discharge and water levels at gauges. We show that a simple hydrodynamic model operating with readily available data is able to provide highly localized information on the expected flood extent and impacts, with simulation times enabling operational flood warning. We demonstrate that such an impact forecast would have indicated the deadly potential of the 2021 flood in western Germany with sufficient lead time.

Description: Tourmaline-cemented magmatic-hydrothermal breccias are a major host to sulphide mineralization in the supergiant Río Blanco–Los Bronces (RB–LB) porphyry Cu-Mo district in central Chile. We made an extensive study of the chemical and boron isotopic composition of tourmaline from this district to shed light on the composition and origin of mineralizing fluids and to test the utility of tourmaline as an indicator mineral by comparing compositions from mineralized and barren breccias. Río Blanco-Los Bronces is a world-class porphyry-type Cu-Mo district of late Miocene age hosted in a granodioritic batholith and related porphyry intrusions in central Chile (33°9’ S latitude, 70°17’W longitude). The porphyry intrusions and related orebodies are distributed along a structurally-controlled NW-SE zone. Mineralization comprises quartz-sulfide veins, disseminated sulfide miner-alization in altered porphyry host rocks and disseminated sulfides in hydrothermal breccias. See Toro et al. (2012) for an overview of the geology, geochronology and mineralization in the district. Descriptions of the mineralized tourmaline breccias are given by Frikken et al. (2005) and Skewes et al. (2003). The data set provided here comprises in-situ chemical analyses of tourmaline by electron microprobe (EPMA) as well as in-situ boron-isotope analyses of tourmaline in the same samples by SIMS. Tourmaline was analysed in 12 samples including 8 from mineralized breccia bodies (Sur-Sur: 4, La Americana: 4), and 2 samples each from barren breccia and nearby granite-hosted tourmaline nodules in the Diamante area. We also give results of mass balance calculations testing the hypoth-esis of a magmatic-hydrothermal origin of the boron.

Description: Controls on the deformation pattern (shortening mode and tectonic style) of orogenic forelands during lithospheric shortening remain poorly understood. Here, we use high-resolution 2D thermomechanical models to demonstrate that orogenic crustal thickness and foreland lithospheric thickness significantly control the shortening mode in the foreland. Pure-shear shortening occurs when the orogenic crust is not thicker than the foreland crust or thick, but the foreland lithosphere is thin (〈70–80 km, as in the Puna foreland case). Conversely, simple-shear shortening, characterized by foreland underthrusting beneath the orogen, arises when the orogenic crust is much thicker. This thickened crust results in high gravitational potential energy in the orogen, which triggers the migration of deformation to the foreland under further shortening. Our models present fully thick-skinned, fully thin-skinned, and intermediate tectonic styles in the foreland. The first tectonics forms in a pure-shear shortening mode whereas the others require a simple-shear mode and the presence of thick (〉∼4 km) sediments that are mechanically weak (friction coefficient 〈∼0.05) or weakened rapidly during deformation. The formation of fully thin-skinned tectonics in thick and weak foreland sediments, as in the Subandean Ranges, requires the strength of the orogenic upper lithosphere to be less than one-third as strong as that of the foreland upper lithosphere. Our models successfully reproduce foreland deformation patterns in the Central and Southern Andes and the Laramide province.

Description: atbox - Fault Analysis Toolbox is a python module for the extraction and analysis of faults (and fractures) in raster data. We often observer faults in 2-D or 3-D raster data (e.g. geological maps, numerical models or seismic volumes), yet the extraction of these structures still requires large amounts of our time. The aim of this module is to reduce this time by providing a set of functions, which can perform many of the steps required for the extraction and analysis of fault systems. The basic idea of the module is to describe fault systems as graphs (or networks) consisting of nodes and edges, which allows us to define faults as components, i.e. sets of nodes connected by edges, of a graph. Nodes, which are not connected through edges, thus belong to different components (faults).

Description: In the near-Earth space, there are a large population of high energy electrons trapped by Earth’s magnetic field. These energetic electrons are trapped in the regions called Earth’s ring current and radiation belts. They are very dynamic and show a very strong dependence on solar wind and geomagnetic conditions. These energetic electrons can be dangerous to satellites in the near-Earth space. Therefore, it is very important to understand the mechanisms which drive the dynamics of these energetic electrons. Wave particle interaction is one of the most important mechanisms. Among the waves that can be encountered by the energetic electrons when they move around our Earth, whistler mode chorus waves can cause both acceleration and the loss of energetic electrons in the Earth's radiation belts and ring current. To quantify the effect of chorus waves on energetic electrons, we calculated the bounce-averaged quasi-linear diffusion coefficients using the chorus wave model developed by Wang et al (2019) and extended to higher latitudes according to Wang and Shprits (2019). Using these diffusion coefficients, we calculated the lifetime of the electrons with an energy range from 1 keV to 2 MeV. In each magnetic local time (MLT), we calculate the lifetime for each energy and L-shell using two different methods according to Shprits et al (2007) and Albert and Shprits (2009). We make the calculated electron lifetime database available here. Please notice that the chorus wave model by Wang et al (2019) is valid when Kp 〈= 6. If the user wants to use this lifetime database for Kp 〉6, please be careful and contact the authors.

Description: Climate change and human-driven eutrophication promote the spread of harmful cyanobacteria blooms in lakes worldwide, which affects water quality and impairs the aquatic food chain. In recent times, sedimentary ancient DNA-based (sedaDNA) studies were used to probe how centuries of climate and environmental changes have affected cyanobacterial assemblages in temperate lakes. However, there is a lack of information on the consistency between sediment-deposited cyanobacteria communities versus those of the water column, and on the individual role of natural climatic changes versus human pressure on cyanobacteria community dynamics over multi-millennia time scales. Therefore, this thesis uses sedimentary ancient DNA of Lake Tiefer See in northeastern Germany to trace the deposition of cyanobacteria along the water column into the sediment, and to reconstruct cyanobacteria communities spanning the last 11,000 years using a set of molecular techniques including quantitative PCR, biomarkers, metabarcoding, and metagenome sequence analyses. The results of this thesis proved that cyanobacterial composition and species richness did not significantly differ among different water depths, sediment traps, and surface sediments. This means that the cyanobacterial community composition from the sediments reflects the water column communities. However, there is a skewed sediment deposition of different cyanobacteria groups because of DNA alteration and/or deterioration during transport along the water column to the sediment. Specifically, single filament taxa, such as Planktothrix, are poorly represented in sediments despite being abundant in the water column as shown by an additional study of the thesis on cyanobacteria seasonality. In contrast, aggregate-forming taxa, like Aphanizomenon, are relatively overrepresented in sediment although they are not abundant in the water column. These different deposition patterns of cyanobacteria taxa should be considered in future DNA-based paleolimnological investigations. The thesis also reveals a substantial increase in total cyanobacteria abundance during the Bronze Age which is not apparent in prior phases of the early to middle Holocene and is suggested to be caused by human farming, deforestation, and excessive nutrient addition to the lake. Not only cyanobacterial abundance was influenced by human activity but also cyanobacteria community composition differed significantly between phases of no, moderate, and intense human impact. The data presented in this thesis are the first on sedimentary cyanobacteria DNA since the early Holocene in a temperate lake. The results bring together archaeological, historical climatic, and limnological data with deep DNA-sequencing and paleoecology to reveal a legacy impact of human pressure on lake cyanobacteria populations dating back to approximately 4000 years.

Description: Der Klimawandel und die vom Menschen verursachte Eutrophierung fördern die Ausbreitung schädlicher Cyanobakterienblüten in Seen weltweit, was die Wasserqualität und die aquatische Nahrungskette beeinträchtigt. In jüngster Zeit wurden sedimentäre DNA (sedaDNA)-Studien verwendet, um zu untersuchen, wie sich klimatische- und menschliche Umweltveränderungen von Jahrhunderten auf Cyanobakteriengemeinschaften in Seen ausgewirkt haben. Jedoch fehlen bislang Informationen, wie repräsentativ die im Sediment abgelagerten Cyanobakterien und deren DNA für die Gemeinschaften der Wassersäule sind, sowie zur individuellen Rolle natürlicher klimatischer Veränderungen gegenüber dem menschlichen Einflusses auf die Dynamik von Cyanobakterien über Zeitskalen von Jahrtausenden. Daher wurde in dieser Arbeit sedimentäre alte DNA (sedaDNA) des Tiefen Sees in Nordostdeutschland verwendet, um die Ablagerung von Cyanobakterien entlang der Wassersäule in das Sediment zu verfolgen. Ein Hauptteil dieser Arbeit bildete jedoch die Rekonstruktion von Cyanobakteriengemeinschaften der letzten 11.000 Jahre, unter Verwendung einer Reihe von molekularen Techniken, darunter quantitative PCR, Biomarker, Metabarcoding und Metagenom-Sequenzanalysen. Die Ergebnisse dieser Arbeit beweisen, dass die Cyanobakterien-Zusammensetzung und der Artenreichtum zwischen verschiedenen Wassertiefen, Sedimentfallen und Oberflächensedimenten nicht signifikant unterschiedlich ist. Das bedeutet, dass die Zusammensetzung der Cyanobakteriengemeinschaften aus den Sedimenten die Gemeinschaften der Wassersäule widerspiegelt. Aufgrund von DNA-Veränderungen und/oder -Abbau während des Transports entlang der Wassersäule zum Sediment kommt es jedoch zu einer verzerrten Sedimentablagerung verschiedener Cyanobakterien Arten. Insbesondere sind filamentose Arten wie Planktothrix in Sedimenten schlecht vertreten, obwohl sie, laut Ergebnissen einer zusätzlichen Studie dieser Arbeit zur Saisonalität von Cyanobakterien, in der Wassersäule reichlich vorhanden sind. Im Gegensatz dazu sind aggregatbildende Arten wie Aphanizomenon in Sedimenten relativ gesehen überrepräsentiert, obwohl sie in der Wassersäule relativ selten vorkommen. Diese unterschiedlichen Muster zur Sedimentablagerung verschiedener Cyanobakterien Arten sollten in zukünftigen DNA-basierten paläolimnologischen Untersuchungen berücksichtigt werden. Die Dissertation zeigt auch eine deutliche Zunahme der Cyanobakterien Abundanz während der Bronzezeit, die in vorhergehenden Phasen des frühen und mittleren Holozäns nicht erkennbar war. Dies ist wahrscheinlich durch menschliche Landwirtschaft, Entwaldung und übermäßige Nährstoffzufuhr in den See verursacht worden. Nicht nur die Abundanz von Cyanobakterien wurde durch menschliche Aktivitäten beeinflusst, sondern auch die Zusammensetzung von deren Gemeinschaften, die sich signifikant zwischen Phasen unterscheidet, die durch keinen, moderaten, und intensiven menschlichen Einfluss gekennzeichnet sind. Die in dieser Dissertation präsentierten Daten sind die ersten zu sedimentärer Cyanobakterien-DNA seit dem frühen Holozän eines Sees der gemäßigte Klimazone. Die Ergebnisse vereinen archäologische, historische, klimatische und limnologische Daten mit hochaufgelöster und Hochdurchsatz-DNA-Sequenzierung und belegen, dass der menschliche Einfluss auf Cyanobakteriengemeinschaften in Seen etwa 4000 Jahre zurückreicht.

Description: The data set consists of dispersion curves and the corresponding 2D phase velocity maps based on earthquake generated Rayleigh surface waves and ambient noise, as well as the resultant shear-wave velocity model for entire Scandinavia (Norway, Sweden and Finland). We resolved the crust and mantle to 250 km depth to provide new insight into the maintenance of the Paleozoic Scandes mountain range and the lithospheric architecture of the Precambrian Baltic Shield (Mauerberger et al., in review). For this study, we use the virtual ScanArray network which consists of more than 220 seismic stations of the following contributing networks: The ScanArray Core (1G network, Thybo et al., 2012) consists of 72 broadband instruments which were operated by the ScanArray consortium (Thybo et al., 2021) between 2013-2017. We also used 28 stations from the NEONOR2 (2D network), 20 stations from the SCANLIPS3D (ZR network; England et al., 2015), 72 permanent stations from the Swedish National Seismic Network (SNSN; UP network; SNSN 1904) as well as further 35 permanent stations from the Finnish (HE and FN networks), Danish (DK network), Norwegian (NO network (NORSAR, 1971); NS (University of Bergen, 1982)) and international IU network (ALS/USGS, 1988). Since the exact operation times of the different temporary networks differ, we analyse data between 2014 and 2016, when most of the stations were operational. The pre-processing of the data involved the removal of a linear trend, application of a band-pass filter between 0.5 s and 200 s, downsampling to 5 Hz and deconvolution of the instrument response to obtain velocity seismograms. We also corrected for the misorientations stated in Grund et al., 2017.

Description: Climatically formed alluvial river-terrace sequences offer an exceptional opportunity to study valley-width evolution under similar discharge and lithologic conditions. To investigate additional parameters controlling valley width, we globally compiled alluvial-terrace sequences that have been associated with late Quaternary climate changes. All terrace cross-sections that are accepted to our compilation (1) include both valley sides, (2) show absolute values of distance and height, as well as profile location, and, (3) display a minimum of three terrace levels out of which at least one is preserved as a paired terrace. The terrace width and height measurements are summarized in this dataset. The data are presented as Excel and ASCII tables.

Description: This dataset provides Rapid Science Orbits (RSO) from the Low Earth Orbiter (LEO) satellite GRACE-A. It is part of the compilation of GFZ RSO products for various LEO missions and the appropriate GNSS constellation in sp3 format. The individual solutions for each satellite mission are published with individual DOI as part of the compilation (Schreiner et al., 2022). • The GRACE RSO cover the period: - GRACE-A from 2004 200 to 2017 334 - GRACE-B from 2004 200 to 2017 245 (this DOI) The LEO RSOs in version 1 are generated based on the 24-hour GPS RSOs in two pieces for the actual day with arc lengths of 14 hours and overlaps of 2 hours. One starting at 22:00 and ending at 12:00, one starting at 10:00 and ending at 24:00. For day overlapping arcs two 24h GNSS constellations are concatenated. The accuracy of the LEO RSOs is at the level of 1-2 cm in terms of SLR validation. Each solution in version 1 is given in the Conventional Terrestrial Reference System (CTS) based on the IERS 2003 conventions and related to the ITRF-2008 reference frame. The exact time covered by an arc is defined in the header of the files and indicated as well as in the filename.

Description: Mean S-wave coda quality factors (mean-Qc) were estimated from active ultrasonic transmission (UT) measurements acquired during the STIMTEC project in the URL Reiche Zeche (Saxony, Germany). We used S-coda waves of 88 selected UT measurements carried out in 3 differently oriented boreholes (BH10, BH12, BH16) to estimate the spatial change of the coda quality factor in the targeted rock volume, an anisotropic metamorphic gneiss. We also analysed temporal variation in attenuation before and after hydraulic stimulations performed in two boreholes (BH10, BH17). We formed in total 8 UT groups (see data table "2022-004_Blanke-and-Boese_mean_UT_event_locations") from neighbouring UT measurements within different depths and from separated time intervals (see also Tab. 1 in Blanke et al. 2023), and compare mean-Qc estimates of centre frequencies ranging 3-21 kHz of octave-width frequency bands. Our results show a characteristic frequency-dependence and we find that mean-Qc estimates reveal temporal-variations of attenuation more significantly than those obtained from velocity measurements. The temporal variations are strongly connected to hydraulic stimulation activities resulting in a reduction of the coda quality factor where AE events occurred. Analysis of mean-Qc estimates after a temporal resting phase (with no activity in the rock volume) suggests that frequencies 〉 15 kHz indicate healing of small-scale fractures induced by injections. The study shows that coda analysis is a powerful tool for the detection of damage zones and for monitoring changes of the local fracture network within reservoirs important for exploitation or underground storage of gases and liquids.

Description: This data set is part 2 of this series and compiles whole-rock chemical data for late-Variscan low-F biotite and two-mica granites in the German Erzgebirge, in the Saxothuringian Zone of the Variscan Orogen. The group of F-poor biotite granites is represented by the composite massifs of Kirchberg and Niederbobritzsch, the Plohn Granite Suite (PGS), the Aue Granite Suite (AGS), and the subsurface granites of Beiersdorf und Bernsbach. For the group of two-mica granites, compositional data for the multi-stage Bergen massif and the granites from Lauter and Schwarzenberg are reported (Figure 1). Crystal-melt fractionation was the dominant process controlling the evolution of bulk composition in the course of massif/pluton formation. However, metasomatic and hydrothermal processes involving late-stage residual melts and high-T late- to post-magmatic fluids became increasingly more important in highly evolved units and have variably modified the abundances of mobile elements. Interaction with the various metamorphic country rocks and infiltration of meteoric low-T fluids have further disturbed the initial chemical patterns in the endocontact zones and zones influenced by surface weathering. The data set reports whole-rock geochemical analyses for enclaves, granites, aplites, endocontact rocks, and some facial varieties. The data are presented as Excel (xlsx) and machine-readable txt formats. The content of the excel sheet and further information on the granites and regional geology are provided in the data description file.

Description: This data publication includes geochronological and fission track data used to derive the provenance and pressure-temperature-time-deformation evolution of Indian crust in central Myanmar (results from U/Th-Pb igneous zircon, monazite and titanite dating, U/Th-Pb detrital zircon dating, 40Ar/39Ar dating, Rb-Sr dating, zircon (U,Th)/He dating and zircon and apatite fission-track dating. The data are supplementary material to Min et al. (2022). The data are presented as Excel tables and further decribed by a README (pdf). LA-ICP-MS data fiollows the Community-Derived Standards for LA-ICP-MS U-(Th-)Pb Geochronology by Horstwood et al. (2016) and Ar/Ar geochronology was described in Schaen et al. (2020). The data format is ready to be read by Isoplot (Ludwig, 2008ff).

Description: Gas hydrates are ice-like crystalline compounds made of water cavities that retain various types of guest molecules. Natural gas hydrates are CH4-rich but also contain higher hydrocarbons as well as CO2, H2S, etc. They are highly dependent of local pressure and temperature conditions. Considering the high energy content, natural gas hydrates are artificially dissociated for the production of methane gas. Besides, they may also dissociate in response to global warming. It is therefore crucial to investigate the hydrate nucleation and growth process at a molecular level. The understanding of how guest molecules in the hydrate cavities respond to warming climate or gas injection is also of great importance. This thesis is concerned with a systematic investigation of simple and mixed gas hydrates at conditions relevant to the natural hydrate reservoir in Qilian Mountain permafrost, China. A high-pressure cell that integrated into the confocal Raman spectroscopy ensured a precise and continuous characterization of the hydrate phase during formation/dissociation/transformation processes with a high special and spectral resolution. By applying laboratory experiments, the formation of mixed gas hydrates containing other hydrocarbons besides methane was simulated in consideration of the effects from gas supply conditions and sediments. The results revealed a preferential enclathration of different guest molecules in hydrate cavities and further refute the common hypothesis of the coexistence of hydrate phases due to a changing feed gas phase. However, the presence of specific minerals and organic compounds in sediments may have significant impacts on the coexisting solid phases. With regard to the dissociation, the formation damage caused by fines mobilization and migration during hydrate decomposition was reported for the first time, illustrating the complex interactions between fine grains and hydrate particles. Gas hydrates, starting from simple CH4 hydrates to binary CH4—C3H8 hydrates and multi-component mixed hydrates were decomposed by thermal stimulation mimicking global warming. The mechanisms of guest substitution in hydrate structures were studied through the experimental data obtained from CH4—CO2, CH4—mixed gas hydrates and mixed gas hydrates—CO2 systems. For the first time, a second transformation behavior was documented during the transformation process from CH4 hydrates to CO2-rich mixed hydrates. Most of the crystals grew or maintained when exposed to CO2 gas while some others decreased in sizes and even disappeared over time. The highlight of the two last experimental simulations was to visualize and characterize the hydrate crystals which were at different structural transition stages. These experimental simulations enhanced our knowledge about the mixed gas hydrates in natural reservoirs and improved our capability to assess the response to global warming.

Description: Gashydrate sind eisähnliche, kristalline Verbindungen bestehend aus Wasserkäfigen, in denen verschiedene Arten von Gastmolekülen eingeschlossen sind. Natürliche Gashydrate sind CH4-reich, enthalten aber auch höhere Kohlenwasserstoffe sowie CO2, H2S usw. Sie sind stark von den lokalen Druck- und Temperaturbedingungen abhängig. Aufgrund ihres hohen Energiegehalts werden natürliche Gashydrate zur Produktion von Methangas kontrolliert zersetzt. Sie können sich aber auch als Reaktion auf die globale Erwärmung zersetzen. Daher ist es von entscheidender Bedeutung, den Hydratnukleation und des Wachstumsprozesses auf molekularer Ebene zu verstehen. Es ist auch von großer Bedeutung zu klären, wie die Gastmoleküle in den Hydratkäftigen auf die Erderwärmung oder die Gasinjektion antworten. Diese Arbeit beschäftigt sich mit einer systematischen Untersuchung von einfachen und gemischten Gashydraten unter Bedingungen, die für die natürlichen Hydratvorkommen im Qilian Mountain Permafrost, China, relevant sind. Eine in die konfokale Raman-Spektroskopie integrierte Hochdruckzelle gewährleistet eine präzise und kontinuierliche Charakterisierung der Hydratphase während des Bildungs-/Dissoziations-/Umwandlungsprozesses mit hoher örtlicher und spektraler Auflösung. Anhand von Laborversuchen wurde der Entstehungsprozess von gemischten Gashydraten unter Berücksichtigung der Auswirkungen unterschiedliches Gaszufuhr und Sedimenten simuliert. Die Ergebnisse zeigten eine bevorzugte Einlagerung verschiedener Gastmoleküle in die Hydratkäfige und widerlegen die gängige Hypothese der Bildung koexistierender Hydratphasen aufgrund einer sich ändernden Gasphase. Das Vorhandensein bestimmter Mineralien und organischer Verbindungen in Sedimenten kann ebenfalls erhebliche Auswirkungen auf die koexistierenden festen Phasen haben. Bezüglich der Hydratzersetzung konnte im Rahmen dieser Arbeit erstmals über die Formationsschädigung durch Feinkornmobilisierung und -migration beim Hydratabbau berichtet werden, was die komplexen Wechselwirkungen zwischen feinen Sedimentkörnern und Hydratpartikeln verdeutlicht. Gashydrate, angefangen von einfachen CH4-Hydraten über binäre CH4-C3H8-Hydrate bis hin zu Mehrkomponenten-Mischhydraten, wurden durch thermische Stimulation zersetzt, um die Reaktion auf die globale Erwärmung nachzuahmen. Die Mechanismen der Substitution der Gasmoleküle in Hydratstrukturen wurden anhand der experimentellen Daten von CH4-CO2-, CH4-Mischgashydraten und Mischgashydraten-CO2-Systemen untersucht. Erstmals wurde ein zweites Umwandlungsverhalten während des Umwandlungsprozesses von CH4-Hydraten zu CO2-reichen Mischhydraten dokumentiert. In den meisten Fällen wird das Modell des Schrumpfenden Kerns (Shrinking-core-model) unterstützt, während in einigen anderen Fällen die Kristalle mit konstanter Geschwindigkeit umwandelten. Der Höhepunkt der beiden letzten experimentellen Simulationen war die Visualisierung und Charakterisierung von Hydratkristallen, die sich in verschiedenen strukturellen Übergangsstadien befanden. Diese experimentellen Simulationen erweiterten unser Wissen über gemischte Gashydrate in natürlichen Lagerstätten und verbesserten unsere Fähigkeit, die Reaktion auf die globale Erwärmung zu bewerten.

Description: We present a new Moho map for the north-eastern part of Eurasia, which remains almost non-studied by seismic methods. The new map is based on the analysis of various data sets. The key fields are the residual gravity, topography and vertical gravity gradients of GOCE (Gravity field and steady-state Ocean Circulation Explorer). Using three fields enables improvement of the final results and better separation of the Moho effect. In the first step, the effects of sediments, crystalline crust and upper mantle were removed from the observed fields based on existing crustal and tomography models. The residual fields are then inverted in the next step to find perturbations in the initial Moho map. In the inversion, it is assumed that some density anomalies are still located in the crust and upper mantle. The new Moho map demonstrates several principal features, which were not resolved before. They well correspond to tectonic fragmentation of the study area. In particularly, the crustal root is now located under the Verkhoyansk Range and extends to the depth of 47 km, also the new model demonstrates the Moho deepening in the continental part of the Laptev rift system. Next, the zone of shallow Moho in the East Siberian Sea shore is now clearly traced and has a more isometric shape compared to the initial model. New patterns have been also found in the offshore part of the Chukotka microcontinent and for the Anadyr-Koryak folded system. The new Moho map is a significant improvement of the previous maps showing crustal thickness in north-eastern Eurasia.

Description: The dataset presented here is an earthquake catalog for the central Sea of Marmara (Turkey) obtained by applying a traditional STA/LTA technique to the continuous waveforms. The magnitude of completeness of this catalog is MW = 1.4. The full description of the data processing and creation of the catalog is provided in the paper “Near - fault monitoring reveals combined seismic and slow activation of a fault branch within the Istanbul-Marmara seismic gap in NW Turkey” published by Martínez-Garzón et al., in Seismological Research Letters. The data are provided as the following two ASCII tables: The file 2021-004_Martinez-Garcon-et-al_Initial_seismicity_catalog contains the seismic events for which we could successfully calculate an earthquake location. The ASCII table has the following columns: columns: id, year, month, day, hour, minute, second, serial time, latitude, longitude, depth [km], magnitude, horizontal error [km], vertical error [km], RMS, maximum azimuthal gap [degree]. The table 2021-004_Martinez-Garcon-et-al_Relocated_seismicity_catalog contains the seismic events for which we could refine the initial location and obtain a double-difference refined location. The ASCII table has the following columns: id, latitude, longitude, depth [km], horizontal error [km], vertical error [km].

Description: This data publication contains seismic catalog developed by the analysis of seismicity recorded during hydraulic stimulation campaign performed in May 2020 in the 5.8-km deep OTN-2 well near Helsinki, Finland as part of the St1 Deep Heat project (Kwiatek et al., 2022). The original seismic data to develop the seismic catalog were acquired with the high-resolution seismic network composed of 22 geophones surrounding the project site. The centerpiece of the network was a 10-level borehole array of Geospace OMNI-2400 geophones (3C/15 Hz) sampled at 2 kHz placed in the OTN-3 well adjacent to the OTN-2 injection well, and located at 1.93 - 2.55 km depth, approx. 3km from injection intervals. Additional 12 stations at distances 〈10 km from project site formed the satellite network that was equipped with short-period 3C 4.5 Hz Sunfull PSH geophones, completing the seismic network. Near-real-time processing of induced seismicity data started on Jan 26, 2020, i.e. about 3 months prior to the onset of the injection, covering entire period of the stimulation campaign in May 2020. The monitoring stopped end of June 2020, about one month after the stimulation finished. The monitoring campaign resulted in initial industrial seismicity catalog containing 6,243 events that was refined and further extended (cf. Kwiatek et al., 2022). The final catalog associated with this data publication contains 6,318 earthquakes, including 197, 5427 and 694 events recorded before, during, and after stimulation campaign. The core catalog data contains origin time, local magnitude, (re)location and focal mechanism data.

Description: Bed load sediment transport governed by particle saltation in supercritical open channel flows cause bedrock incision in high-gradient mountain streams, and hydro-abrasion at hydraulic structures. Hence, a better understanding of turbulent flow characteristics and particle dynamics are of prime importance for the prediction of river and landscape evolution, and for a sustainable design of hydraulic structures. To this end, we experimentally investigated single particle dynamics in supercritical open channel flows over fixed planar and abraded beds covering smooth, transitionally rough, and hydraulically rough regimes. The experiments were performed at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) of ETH Zürich in a wide range of hydraulic conditions with various channel width-to-depth aspect ratios (b/ho) and Froude numbers (F). We investigated the motions of five particle groups differing in shape, hardness, and diameter. By means of a high-speed camera, the particle velocities and trajectory parameters such as hop height and hop length were determined using Particle Tracking Velocimetry (PTV). The results reveal that at least 120 individual particles should be used in the tests to determine sound statistics of particle trajectories. In the present test conditions, the particles are dominantly transported in saltation. The effects of particle properties such as shape and diameter on the particle trajectories are negligible, while the rolling probability of the particles for a given flow condition increases with increasing diameter. Bed roughness was found to be the key parameter having a significant effect on the saltation trajectories and horizontal energy transfer. Hop height, hop length and particle velocities as well as horizontal energy transfer increase with increasing bed roughness. Based on the saltation trajectory data, non-dimensional equations are developed for each hydraulic regime and used to enhance the saltation-abrasion model by Sklar and Dietrich (2004). The present findings contribute to a better understanding of particle motion characteristics under different hydraulic and roughness conditions and their effect on mechanics and prediction of bedrock incision and hydro-abrasion in three-dimensional supercritical open channel flows occurring in steeply sloped rivers and at hydraulic structures.

Description: Fault zones are major sources of hazard for many populated regions around the world. Earthquakes still occur unanticipated, and research has started to observe fault properties with increasing spatial and temporal resolution, having the goal of detecting signs of stress accumulation and strength weakening that may anticipate the rupture. The common practice is monitoring source parameters retrieved from measurements; however, model dependence and strong uncertainty propagation hamper their usage for small and microearthquakes. Here, we decipher the ground motion (i.e., ground shaking) variability associated with microseismicity detected by dense seismic networks at a near-fault observatory in Irpinia, Southern Italy, and obtain an unprecedentedly sharp picture of the fault properties evolution both in time and space. We discuss the link between the ground-motion intensity and the source parameters of the considered microseismicity, showing a coherent spatial distribution of the ground-motion intensity with that of corner frequency, stress drop, and radiation efficiency. Our analysis reveals that the ground-motion intensity presents an annual cycle in agreement with independent geodetic displacement observations from two Global Navigation Satellite System stations in the area. The temporal and spatial analyses also reveal a heterogeneous behavior of adjacent fault segments in a high seismic risk Italian area. Concerning the temporal evolution of fault properties, we highlight that the fault segment where the 1980 Ms 6.9 Irpinia earthquake nucleated shows changes in the event-specific signature of ground-motion signals since 2013, suggesting changes in their frictional properties. This evidence, combined with complementary information on the earthquake frequency–magnitude distribution, reveals differences in fault segment response to tectonic loading, suggesting rupture scenarios of future moderate and large earthquakes for seismic hazard assessment.

Description: The study of serpentinites and ophicarbonates from ophiolitic terrains provides a three-dimensional perspective on the hydration and carbonation processes affecting modern oceanic lithosphere. The Chenaillet ophiolite (western Alps) is interpreted as a fragment of an oceanic core complex that resembles a modern slow spreading center, and it was weakly affected by Alpine metamorphism. Ophicarbonates from the Chenaillet ophiolite were targeted in this study for in situ analysis by Secondary Ion Mass Spectrometry (SIMS) of oxygen and carbon isotopes in serpentine, calcite, dolomite and magnetite. The high spatial resolution of SIMS allowed us to target different serpentine, carbonate and magnetite generations intergrown at scales ≤ 50 μm, and reveal systematic zoning in δ18O with a range of 5.8‰ in serpentine (from 3.0 to 8.8‰, V-SMOW), 21.2‰ in carbonate (9.4 to 30.6‰), and 5.6‰ in magnetite (–5.0 to –10.6‰). Coupled analysis of oxygen isotopes in seven different touching-pairs of co-crystallized serpentine+carbonate and serpentine+magnetite provides independent constraints on both the temperatures and δ18O(water) values during serpentinization and carbonation responsible for the formation of the Chenaillet ophicarbonates. The new stable isotope data and thermometric estimates can be directly linked to textural and petrographic observations. These new results identify at least four different stages of hydrothermal alteration in the Chenaillet ophicarbonates: (1) peridotite hydration during seafloor exhumation at temperatures down to 200-130 °C and water δ18O values varying from 5 to 2‰, as documented by serpentine+magnetite in mesh textures; (2) carbonation during exhumation near the seafloor at temperatures as low as 10 °C assuming water δ18O values of –1‰, as documented by the highest oxygen isotope ratios in texturally older calcite; (3) serpentinization and carbonation at temperatures up to 240 °C and water δ18O values of 2-3‰, as documented by serpentine+magnetite in veins crosscutting mesh textures (T = 192±66 °C, δ18O(water) = 2±1‰, 2 standard deviation), serpentine+magnetite (T = 182±32 °C, δ18O(water) = 2±1‰) and serpentine+dolomite (T = 243±79 °C, δ18O(water) = 3±2‰) in recrystallized hourglass domains within serpentinite clasts, serpentine+dolomite (T = 229±50 °C, δ18O(water) = 3±1‰) and serpentine+calcite (T = 208±40 °C, δ18O(water) = 2±1‰) within the fine-grained calcite matrix surrounding serpentinite clasts; (4) late stage carbonation at temperatures down to 70-40 °C assuming water δ18O values of 3 to –1‰, as documented by the highest oxygen isotope ratios in a large calcite vein crosscutting both serpentinite clasts and fine-grained carbonate matrix. We suggest that the textural and isotopic observations are consistent with a protracted serpentinization and carbonation of the lithospheric mantle that started during progressive exhumation to the seafloor and continued due to interaction with hot and isotopically shifted seawater, which circulated at depth in the oceanic crust and was then discharged near the seafloor, similar to modern mid-ocean ridge venting systems.

Description: Mineral exploration is facing greater challenges nowadays because of the increasing demand for raw materials and the lesser chance of finding large deposits at shallow depths. To be efficient and address new exploration challenges, high-resolution and sensitive methods that are cost-effective and environmentally friendly are required. In this work, we present the results of a sparse 3D seismic survey that was conducted in the Zinkgruvan mining area, in the Bergslagen mineral district of central Sweden. The survey covers an area of 10.5 km2 for deep targeting of massive sulphides in a polyphasic tectonic setting. A total of 1311 receivers and 950 shot points in a fixed 3D geometry setup were employed for the survey. Nine 2D profiles and a smaller 3D mesh were used. Shots were generated at every 10 m, and receivers were placed at every 10–20 m, along the 2D profiles, and 40–80 m in the mesh area. An analysis of the seismic fold coverage at depth was used to determine the potential resolving power of this sparse 3D setup. The data processing had to account for cultural noise from the operating mine and strong source-generated surface waves, which were attenuated during both pre- and post-stack processing steps. The processing workflow employed a combination of 2D and 3D refraction static corrections, and post-stack FK filters along inlines and crosslines. The resulting 3D seismic volume is correlated with downhole data (density and P-wave, acoustic impedance, reflection coefficient), synthetic seismograms, surface geology and a 3D model of mineral-bearing horizons in order to suggest new exploration targets at depth. The overall geological architecture at Zinkgruvan is interpreted as two EW overturn folds, an antiform and a synform, affected by later NS-trending folding. Two strong sets of shallow reflections, associated with the Zn–Pb mineralization, are located at the hinge of an EW-trending antiform, while a strong set of reflections, associated with the main mineralization, is located at the overturned apex of the EW synform. The NS Knalla fault that crosses the study area terminates the continuation of the mineral-bearing deposits at depth towards the west, a conclusion solely based on the reflectivity character of the seismic volume. This study illustrates that sparse 3D data acquisition, while it has its own challenges, can be a suitable replacement for 2D profiles while line cutting, and environmental footprints can totally be avoided.

Description: The Atacama Desert is a unique landscape to understand the evolution of the Earth in extremely arid environments. Clay pans are crucial to comprehend the surface and subsurface processes in areas limited by water availability. We present an integrated geoscientific study to investigate the sedimentary deposits of the Paranal clay pan located in the hyperarid core of the Atacama Desert. We used the loop source transient electromagnetic (TEM) method complemented by magnetics and active seismics to resolve different subsurface properties at different spatial scales. A total of 116 soundings were processed, analyzed, and inverted to investigate the resistivity distribution of the clay pan. The TEM-1D inversion results reveal a three-layered resistivity structure with reliable information down to a depth of 250 m. Colluvial and lacustrine sediments reach a maximum thickness of about 160 ± 10 m. The shape of the lacustrine sediments suggests the presence of an old paleochannel that might be part of the former main Paranal drainage network. In addition, the basement below the clay pan can be partly interpreted as a damaged zone of an inferred strike-slip fault system. Subsequent 2D magnetic modeling confirms the basement depth derived from the TEM results. The seismic transects reveal accurate structural information of the upper 60 m and are consistent with TEM-1D models. High P wave velocities correlate with high electrical conductivity layers and are interpreted as lacustrine sediments. Our work provides key information with respect to the sedimentary thickness above the basement contributing to paleoclimate research in northern Chile.

Description: The global gravitational potential generated by the attraction of the Earth’s topographic masses has been computed in spectral domain. The mass-source information is provided by the 1 arcmin resolution Earth2014 relief model and four averaged density values for rock, ocean, lake, and ice areas. The topography and bathymetry are split into confocal ellipsoidal shells of a defined thickness. Based on the provided mass-source information, the gravitational potential is expanded for each shell and then summed up to represent the complete gravitational potential of the topography (and bathymetry). In this contribution, we present the impact of different shell thicknesses to the model accuracy and computation time. Moreover, we expanded our topographic gravity field model up to spherical harmonic degree and order 5,494. Such short scale mass information represented by the topography can be used to complement high-resolution combined static gravity field models for the very high-frequency components of the gravity field. As an example, we enhanced (augmented) EIGEN-6C4 model with the high frequency components retrieved from the topographic model. The deflections of vertical values computed from the augmented model are compared w.r.t. ground truth observations in Germany, Southern Colorado and Iowa (USA) which suggest as expected a considerable improvement over rugged mountainous regions and comparable residuals in areas of moderate topography.

Description: The Bureau of Products and Standards (BPS) is a key component of the Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG). It supports GGOS in its goal to provide consistent geodetic products needed to monitor, map, and understand changes in the Earth’s shape, rotation, and gravity field. In its present structure, the two Committees “Earth System Modeling” and “Essential Geodetic Variables” as well as the Working Group “Towards a consistent set of parameters for the definition of a new Geodetic Reference System (GRS)” are associated to the BPS. This paper presents the structure and role of the BPS and it highlights some of the recent activities. A major focus is on the classification and description of geodetic products and their representation at the renewed GGOS website (www.ggos.org). This website serves as an “entrance door” to geodetic products to satisfy different user needs and communities (e.g., geodesists, geophysicists, other geosciences and further customers) in order to make geodesy more visible to other disciplines and to society.

Description: It is widely recognized that collisional mountain belt topography is generated by crustal thickening and lowered by river bedrock erosion, linking climate and tectonics. However, whether surface processes or lithospheric strength control mountain belt height, shape and longevity remains uncertain. Additionally, how to reconcile high erosion rates in some active orogens with long-term survival of mountain belts for hundreds of millions of years remains enigmatic. Here we investigate mountain belt growth and decay using a new coupled surface process and mantle-scale tectonic model. End-member models and the new non-dimensional Beaumont number, Bm, quantify how surface processes and tectonics control the topographic evolution of mountain belts, and enable the definition of three end-member types of growing orogens: type 1, non-steady state, strength controlled (Bm 〉 0.5); type 2, flux steady state, strength controlled (Bm ≈ 0.4−0.5); and type 3, flux steady state, erosion controlled (Bm 〈 0.4). Our results indicate that tectonics dominate in Himalaya–Tibet and the Central Andes (both type 1), efficient surface processes balance high convergence rates in Taiwan (probably type 2) and surface processes dominate in the Southern Alps of New Zealand (type 3). Orogenic decay is determined by erosional efficiency and can be subdivided into two phases with variable isostatic rebound characteristics and associated timescales. The results presented here provide a unified framework explaining how surface processes and lithospheric strength control the height, shape, and longevity of mountain belts.

Description: The present study investigates azimuthal anisotropy and its relation to the geodynamical processes beneath the back-arc of the Hellenic subduction zone in the eastern Aegean and western Anatolia where surface tectonics is dominated by the right-lateral strike-slip North Anatolian Fault Zone (NAFZ) in the north and E-W oriented normal fault systems. We obtained apparent SKS splitting parameters from 1,660 good quality and 137 null measurements extracted from 542 events recorded at 40 permanent broadband seismic stations. Overall, the station-averaged splitting parameters indicate NNE-SSW oriented fast directions (∼N20°E) and splitting delays around ∼1.5 s. The large splitting delays, particularly observed beneath the northern Aegean can be explained by either an enlarged mantle wedge thickness or increased strength of upper mantle anisotropy. We constrain complex anisotropy structures within two layer models from notable backazimuthal variations in individual splitting measurements observed beneath a few stations at the north located in a close proximity to the NAFZ and central-western Anatolia. At the western end of the NAFZ, our estimated upper layer anisotropy direction (at ∼120 km) is rather parallel to the NAFZ reflecting the imprint of a lithospheric petrofabric formed by recent deformation while in central-western Anatolia they correlate well with maximum shear directions and small splitting delays (∼0.6 s) appear to further support relatively thin lithosphere (∼90 km). An overall pattern of extension-parallel fast directions (N10°E) within lower layer can be attributed to the slab rollback-induced mantle flow that is highly oblique with respect to the WSW-ward motion of the Anatolian lithosphere.

Description: High-quality maps of Geothermal heat flow (GHF) are crucial when modeling ice dynamics, shape, and mass loss of the Antarctic Ice Sheet, which is one of the largest potential contributors to sea level rise. The determination of GHF remains challenging, as in situ data are sparse and geophysical models exhibit large discrepancies in amplitude and resolution, especially on regional scales. Using a novel approach implementing a joint inversion of gravity and seismic tomography data with various geophysical and mineral physics information, we estimate the 3D thermal lithospheric structure and present a new GHF map. The resulting surface heat flow correlates with the location of subglacial volcanism and can represent a boundary condition for accurate ice dynamics models that can explain observed acceleration in the ongoing ice mass loss. Absolute values are within the range of other seismology-based methods and are much lower than those obtained using for example, magnetic data. High uncertainties remain in the parametrization of the upper crustal structure and thermal parameters.

Description: The Critical Zone (CZ) is the thin, near-surface zone of terrestrial Earth, extending from the canopy of trees to the groundwater table. Within this system, coupled chemical, biological, physical, and geological processes operate together to support life at the Earth's surface. A major consideration in Critical Zone research is quantitatively predicting mass transfer fluxes between different compartments like soil, bedrock, water and biomass, and evaluating the influence of environmental forces on mass transfer. Elements (e.g., Li, Mg, Ca, Sr) concentrations and their isotopes have been widely employed to quantify mass transfer. Critical Zone processes, including primary mineral dissolution, secondary mineral formation, adsorption/desorption, biological recycling, are generally associated with different fractionation factors for a specific isotopic system. Therefore, measured isotope ratios along with concentrations could fingerprint the reaction pathways and magnitude of Critical Zone processes. In this study, I have chosen the stable isotopes of Lithium (Li) and Magnesium (Mg) isotope tools to investigate Critical Zone processes. Mg and Li constitute nutritive and non-nutritive elements, respectively, Conventwald (the Black Forest, south Germany) was chosen as the research site as this site has been intensively monitored. By comprehensive sampling (including plant tissues, soil, bedrock, saprolite,subsurface flow, groundwater, creek water and wet precipitation samples), Critical Zone processes encompassing different time scales were investigated, e.g. how rock was converted into soil, how water chemistry evolves from precipitation to runoff and how biomass recycle nutritive elements. In addition, effort was made to balance Li, Mg isotope budgets at the catchment scale. The Mg isotopic composition (the 26Mg/24Mg ratio expressed as δ26Mg in permil) is similar between soil and regolith samples, and is higher than that of bedrock. This was attributed to preferential dissolution of amphibole and formation of secondary minerals during pedogenesis. Mg hosted in neoformed secondary minerals accounts for ~ 50% of total Mg in the soil as calculated by mass balance. Water samples did not show seasonal variability, despite large variation in dissolved Mg concentration. Subsurface flow samples have similar δ26Mg values to the regolith exchangeable fraction at the respective sampling depths. Groundwater and creek water also show δ26Mg values that are identical to those of the exchangeable fraction in the deep regolith. I suggest that cation-exchange processes in the regolith buffer δ26Mg of creek water at our study site. To further explore this hypothesis, adsorption and desorption experiments using soil samples from our study site were carried out. The results showed negligible Mg isotope fractionation during adsorption-desorption, supporting our hypothesis that water δ26Mg is in equilibrium of corresponding exchangeable δ26Mg in this study site. The large pool of Mg in the exchangeable fraction of the deep regolith (〉3 m) is isotopically light and presents most likely the Mg residue in soil water that entered the exchangeable pool after secondary mineral II formation - a process which often favours heavy Mg isotopes. The exchangeable fraction in the shallow regolith (0-3 m depth) shows a strong imprint of biological cycling. Plant uptake of Mg starts from ~3m, which drives the exchangeable δ26Mg more negative towards the surface, but super-imposed on this the plant-recycled isotopically-heavy Mg is returned to the soil, enriching the exchangeable fraction of the top ~1.5m of soil in heavy Mg isotopes. Mg isotopes thus provide an exact depth image of the geogenic (weathering) and the organic (bio-cycled) nutrient cycle. At the catchment scale, dissolved Mg exported by creek water relative to the total export of solute and particulate Mg is 41 ±11% as calculated by an isotope balance equation. Li isotopes show different behaviour in the Critical Zone as compared to Mg isotopes. Li fluxes calculation show that wet precipitation and plant uptake have negligible impact on Li cycling in the catchment. Therefore, the 7Li/6Li ratio (expressed as δ7Li in permil) is a good tracer for abiotic weathering. Both subsurface flow and creek water show seasonal variation in δ7Li, while groundwater exhibits negligible δ7Li variation. Along with measurement of bedrock, bulk regolith, clay- sized fraction, vegetation and the exchangeable fraction of regolith, I suggest that δ7Li variation in different water reservoirs indicate different chemical evolution pathways. δ7Li in shallow subsurface flow (0-15 cm) become more positive with increasing Li concentration, and a binary mixing process could be identified with two endmembers being throughfall and pre-event soil solution. During rainfall events, dilute precipitation (enriched in 6Li) flushed old, concentrated soil solution (enriched in 7Li) retained in the soil matrix, and thus a mixing pattern was seen in 1/Li-δ7Li space. Groundwater exhibits negligible δ7Li variation despite Li concentration and groundwater table fluctuations, which most likely reflects a buffering effect of deep exchangeable pool. This interpretation is similar to the one I offer to explain the invariance of δ26Mg in groundwater. The only difference is that isotope fractionation occurs during Li exchange, as groundwater is ~ 4 ‰ heavier than the corresponding exchangeable pool δ7Li, while negligible fractionation is observed for Mg isotopes. In creek water samples, δ7Li covaried with proportion of Li remaining in the solution. This fractionation could be attributed to Li incorporation or adsorption to secondary minerals during downstream transport, favouring 6Li. Surprisingly, despite the heavy δ7Li exported in dissolved form, saprolite and soil are almost isotopically identical to bedrock. A reservoir or flux enriched in 6Li is missing. Several potential factors are discussed to account for this isotope imbalance and the potential reservoir or fluxes are listed. As separated clay-sized fraction from soil is enriched in 6Li, it is likely that fine particulates that are preferentially exported by subsurface flow could be the missing flux. In summary, contrasting Mg and Li recycling regimes were observed in this research. As anticipated, Mg was more involved in biological recycling compared to Li. Primary minerals in the bedrock showed homogenous δ7Li but heterogeneous δ26Mg, III and therefore preferential dissolution of hornblende induced δ26Mg variation in the weathering regolith but not for δ7Li. The biggest difference between δ7Li and δ26Mg variation is seen in water samples: subsurface flow, groundwater and creek water showed negligible seasonal variation in δ26Mg, but this is not the case for δ7Li. I attribute the invariance of water δ26Mg to the buffering effect of exchangeable pool. By contrast, only groundwater exhibited invariant δ7Li. While this might also reflect the buffering effect of exchangeable pool, large δ7Li variability in subsurface flow and creek water requires different explanations. Two-endmember mixing and further Li incorporation into secondary minerals were put forward to explain δ7Li variation in subsurface flow and creek water respectively. For both elements, secondary mineral formation is the most important process fractionating isotopic composition of water at this study site

Description: Die kritische Zone (Englisch: Critical Zone, CZ) ist die dünne, oberflächennahe Schicht der festen Erde, die sich von den Baumwipfeln bis zum Grundwasserspiegel erstreckt. Innerhalb dieser Zone wirken gekoppelte chemische, biologische, physikalische und geologische Prozesse zusammen, und schaffen dadurch die Bedingungen für Leben auf der Erdoberfläche. In der Erforschung der kritischen Zone sind die quantitative Berechnung des Massentransportflusses zwischen den verschiedenen Komponenten Boden, Grundgestein, Wasser und Biomasse, sowie die Messung von Umwelteinflüssen auf den Massentransport wesentliche Aspekte. Zur Quantifizierung dieses Massentransports wurden häufig Elementkonzentrationen (z.B. von Li, Mg, Ca, Sr) und deren stabile Isotope eingesetzt. Grundsätzlich sind mit den Prozessen in der kritischen Zone, zu denen die Auflösung von Primärmineralen, Bildung von Sekundärmineralen, Adsorption und Desorption und biologisches Recycling gehören, verschiedene Fraktionierungsfaktoren für bestimmte stabile Isotopensysteme verbunden. Daher können die gemessenen Isotopenverhältnisse zusammen mit den Konzentrationen einen Nachweis über Reaktionswege und Ausmaßder Prozesse in der kritischen Zone liefern. In dieser Studie habe ich zur Untersuchung von Prozessen in der kritischen Zone die Systeme der stabilen Isotope von Magnesium (Mg) und Lithium (Li) ausgewählt, wobei Mg als ein Nährstoff für Pflanzen gilt, während Li kaum aufgenommen wird. Das Untersuchungsgebiet Conventwald (Schwarzwald, Süddeutschland) wurde ausgewählt, da dort bereits intensive Beobachtungen durchgeführt wurden. Eine umfassende Beprobung einschließlich Pflanzengewebe, Boden, unverwittertes Gestein, Saprolith, unterirdischer Wasserfluss, Grundwasser, Bachwasser und Niederschlagswasser ermöglicht die Untersuchung von Prozessen in der kritischen Zone. Prozesse in dieser Zone laufen auf verschiedenen Zeitskalen ab, wie beispielsweise die Umwandlung von Gestein in Boden, die Änderung der Wasserchemie vom Niederschlag zum Abfluss oder das Nährstoffrecycling der Biomasse. Zusätzlich zu diesen Untersuchungen habe ich ermittelt, ob ein Gleichgewicht der Isotopenhaushalte von Li und Mg im Einzugsgebiet besteht. Die Isotopenzusammensetzung der stabilen Isotope des Mg (das Verhältnis 26Mg/24Mg wird ausgedrückt durch δ26Mg in Promille) ist ähnelt sich in Boden- und Regolithproben aber ist höher als im unverwitterten Gestein. Dies kann auf die bevorzugte Auflösung von Amphibol und die Bildung von Sekundärmineralen während der Verwitterung zurückgeführt werden. Das in den ausgefällten Sekundärmineralen enthaltene Mg macht in der Massenbilanz etwa 50% des gesamten Mg im Boden aus. In den Wasserproben zeigen sich keine saisonalen Schwankungen, obwohl die Konzentration des gelösten Mg stark variiert. Proben aus dem Bodenwasser weisen ähnliche δ26Mg Werte wie die austauschbare Fraktion des Regoliths in den jeweiligen Beprobungstiefen auf. Im Grund- und Bachwasser sind die δ26Mg Werte ebenfalls identisch mit der austauschbaren Fraktion des tiefen Regoliths. Vermutlich puffern Kationenaustauschprozesse im Regolith das δ26Mg des Bachwassers an unserem Untersuchungsstandort. Um diese Hypothese zu untersuchen, wurden Adsorptions- und Desorptionsexperimente an Bodenproben durchgeführt. Die Ergebnisse zeigen eine vernachlässigbare Mg Isotopenfraktionierung während Adsorption und Desorption. Das stützt unsere Hypothese, dass sich das δ26Mg des Wassers im Gleichgewicht mit dem zugehörigen austauschbaren δ26Mg befindet. Der große Mg Pool in der austauschbaren Fraktion des tiefen Regoliths (〉3 m) ist isotopisch leicht und stellt höchstwahrscheinlich die Mg Rückstände im Bodenwasser dar, die nach der Sekundärmineralbildung in den austauschbaren Pool gelangten – ein Prozess, der häufig schwere Mg Isotope bevorzugt. Die austauschbare Fraktion des flachen Regoliths (0-3 m) zeigt deutliche Spuren des biologischen Kreislaufs. In ~3 m Tiefe beginnt die Mg Aufnahme durch Pflanzen, wodurch das austauschbare δ26Mg zur Oberfläche hin negativer wird. Durch die Zurückführung von isotopisch schwerem Mg in den Boden wird dieses Signal überlagert, so dass die austauschbare Fraktion in den oberen ~1.5m des Bodens mit schweren Mg Isotopen angereichert wird. Daher liefern Mg Isotope ein exaktes Tiefenprofil des geogenen (Verwitterung) und organischen (biologisches Recycling) Nährstoffkreislaufs. In der Größenordnung des Einzugsgebiets beträgt der Export von gelöstem Mg durch das Bachwasser im Verhältnis zum Gesamtexport von gelösten und partikulärem Mg 41 ± 11%, berechnet mit einer Isotopen Massenbilanz. Die stabilen Isotope des Li Isotope zeigen ein anderes Verhalten in der kritischen Zone als Mg. Die Berechnung der Li Flüsse zeigt, dass Niederschlag und Pflanzenaufnahme einen vernachlässigbaren Einfluss auf den Li Kreislauf im Einzugsgebiet haben. Daher ist das 7Li/6Li Verhältnis (ausgedrückt durch δ7Li in Promille) ein guter Indikator für abiotische Verwitterung. Der Fluss von sowohl Bodenwasser als auch Abfluss zeigt saisonale Schwankungen in δ7Li, wobei im Grundwasser die δ7Li Schwankungen vernachlässigbar sind. Zusammen mit den Messungen von Proben des unverwitterten Gesteins, Regoliths, der tongroßen Fraktion, Vegetation und der austauschbaren Fraktion des Regoliths nehmen wir an, dass die δ7Li Schwankungen in verschiedenen Wasserreservoiren unterschiedliche chemische Entwicklungswege aufzeigen. Im Bodenwasser (0-15 cm) wird δ7Li mit zunehmender Li Konzentration höher; ein binärer Mischungsprozess mit den zwei Endgliedern - Baumkronendurchlass und Bodenlösung durch Wasser von vorherigen Niederschlagsereignissen - konnte bestimmt werden. Während Niederschlagsereignissen spült verdünnter Niederschlag (angereichert in 6Li) alte, konzentrierte Bodenlösung (angereichert in 7Li), die in der Bodenmatrix gespeichert ist, aus, wodurch ein Mischungsmuster im 1/Li-δ7Li Raum zu beobachten ist. Das Grundwasser weist trotz der Li Konzentrationen und Verändergen des Grundwasserspiegels vernachlässigbare Schwankungen von δ7Li auf, die wahrscheinlich auf eine Pufferwirkung des tiefen austauschbaren Pools zurückzuführen sind. Diese Interpretation ist ähnlich zu der, die ich zur Erklärung der Invariabilität von δ26Mg im Grundwasser gebe. Der einzige Unterschied ist, dass beim Austausch die Li Isotope fraktioniert werden, da das Grundwasser ~ 4 ‰ schwerer ist als der dazugehörige austauschbare δ7Li Pool, während die Isotopenfraktionierung für Mg vernachlässigbar ist. In Proben des Bachwassers kovariiert δ7Li mit dem Li Anteil, der in Lösung verbleibt. Diese Fraktionierung kann auf den Einbau von Li oder die Adsorption an Sekundärminerale während des Abwärtsflusses zurückgeführt werden, bei dem 6Li bevorzugt wird. Überraschenderweise sind Saprolith und Boden isotopisch nahezu identisch zum unverwitterten Gestein, obwohl schweres δ7Li in der gelösten Form exportiert wird. Um das Isotopenungleichgewicht zu erklären, fehlt ein Reservoir oder Fluss, der in 6Li angereichert ist. Einige potenzielle Faktoren, die dieses Ungleichgewicht erklären können, werden erörtert und potenzielle Reservoire und Flüsse aufgelistet. Es ist wahrscheinlich, dass der bevorzugte Transport von feinen Partikeln durch den unterirdischen Wasserfluss der fehlende Fluss ist, da die abgetrennte tongroße Fraktion des Bodens in 6Li angereichter ist. In dieser Studie wurden die gegensätzlichen Recycling-Regime Mg und Li untersucht. Mg ist im Vergleich zu Li wie erwartet stärker involviert in biologisches Recycling. Primärminerale im Grundgestein wiesen ein homogenes δ7Li, aber heterogenes δ26Mg auf, daher können wir annehmen, dass die bevorzugte Auflösung von Hornblende zu Variationen in δ26Mg, aber nicht in δ7Li führt. Der größte Unterschied der δ7Li und δ26Mg Schwankungen ist in den Wasserproben sichtbar: unterirdischer Wasserfluss, Grundwasser und Bachwasser zeigten vernachlässigbare saisonale Schwankungen in δ26Mg, was aber nicht für δ7Li zutrifft. Die Invariabilität von δ26Mg im Wasser führe ich auf den Puffereffekt des austauschbaren Pools zurück. Im Gegensatz dazu weist nur Grundwasser invariables δ7Li auf. Während das ebenfalls die Pufferwirkung des austauschbaren Pools reflektieren könnte, benötigt die große Variabilität in δ7Li im tiefen Wasserfluss und Bachwasser andere Erklärungen. Als Erklärung für diese Variabilität wurde ein binärer Mischungsprozess und weiterer Einbau von Li in Sekundärminerale vorgeschlagen. Für beide Elemente ist die Sekundärmineralbildung der wichtigste Prozess, der für die Fraktionierung der Isotope in den Wassern am Untersuchungsstandort verantwortlich ist. de

Description: Using first-principles calculations in combination with special quasirandom structure and occupation control matrix methods, we study the magnetic ordering and the effect of pressure on manganese sulfide polymorphs. At ambient conditions, MnS is commonly observed in paramagnetic rock-salt structure, but as temperature decreases at constant pressure it becomes antiferromagnetic. On the other hand, at room temperature MnS has shown to undergo structural transformations as pressure increases. Here, we show that our approach involving the ordering/disordering of the local magnetic moments in addition to the explicit control of the localization of the Mn d-electrons produces energy band gaps and local magnetic moments in excellent agreement with those observed experimentally, particularly for paramagnetic MnS. Finally, we focus on how MnS evolves under pressure and from its enthalpy landscape we identify at about 21 GPa, the structural transformation from rock-salt to orthorhombic MnP-type. This structural transformation resembles closely experimental results in which a new stable but unidentified MnS phase was previously reported.

Description: Machine-learning (ML) methods have seen widespread adoption in seismology in recent years. The ability of these techniques to efficiently infer the statistical properties of large datasets often provides significant improvements over traditional techniques when the number of data are large (millions of examples). With the entire spectrum of seismological tasks, for example, seismic picking and detection, magnitude and source property estimation, ground-motion prediction, hypocenter determination, among others, now incorporating ML approaches, numerous models are emerging as these techniques are further adopted within seismology. To evaluate these algorithms, quality-controlled benchmark datasets that contain representative class distributions are vital. In addition to this, models require implementation through a common framework to facilitate comparison. Accessing these various benchmark datasets for training and implementing the standardization of models is currently a time-consuming process, hindering further advancement of ML techniques within seismology. These development bottlenecks also affect “practitioners” seeking to deploy the latest models on seismic data, without having to necessarily learn entirely new ML frameworks to perform this task. We present SeisBench as a software package to tackle these issues. SeisBench is an open-source framework for deploying ML in seismology—available via GitHub. SeisBench standardizes access to both models and datasets, while also providing a range of common processing and data augmentation operations through the API. Through SeisBench, users can access several seismological ML models and benchmark datasets available in the literature via a single interface. SeisBench is built to be extensible, with community involvement encouraged to expand the package. Having such frameworks available for accessing leading ML models forms an essential tool for seismologists seeking to iterate and apply the next generation of ML techniques to seismic data.

Description: Overtopping flows in landslide dams erode and entrain materials on the dam surface resulting in erosional features that undermine the dam stability and facilitate the subsequent outburst flooding. A comprehensive understanding of dam surface evolution is therefore crucial for flood risk assessment and hazard mitigation. In this research, we study the mechanisms that influence the non-uniform morphology evolution of landslide dam breaches (i.e. non-linear variation of the dam surface gradient) through experiments and numerical modeling. Analog landslide dam models, constructed using unconsolidated poorly sorted soils, are exposed to different inflow discharges. We find that although the breach discharge evolves more consistently with the erosion along the sidewalls than with bed erosion, it is the erosion along the bed that controls the change in dam surface profiles. Erosion rates, expressed as a function of the difference between the flow shear stress and the apparent erosion resistance, vary at different points along the dam surface due to localized erosional features induced by scouring. The apparent erosion resistance is found to increase linearly along the dam surface. Dam failure is numerically modeled using depth-averaged equations which assume that the complex evolution of the dam profiles is due to the coupled effects of erosion, entrainment, and channel bed collapse. Good agreement between the observed and modeled dam profiles further demonstrates that the gradual saturation of the breach flow with entrained sediment is responsible for the linear variation of the apparent erosion resistance, which in turn contributes to the formation of the surface scouring.

Description: The current PhD thesis focuses on phengite and majorite as hosts for nitrogen in the deep Earth. NH4-phengite end member was synthesized in piston-cylinder experiments at 700 °C and 4.0 GPa, and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD) with Rietveld refinement, and Fourier transform infrared (FTIR) spectroscopy. Its devolatilization behavior (loss of OH and NH4+) was studied by means of in situ micro-FTIR spectroscopy under low and high temperatures (T) using a Linkam cooling-heating stage, and under high pressure (P) conditions in diamond anvil cell (DAC) experiments. To define the extent of NH4+ substitution for K+ in phengite at the same P-T conditions, NH4+/K+ exchange coefficients between aqueous fluids and phengite were experimentally determined in piston-cylinder experiments using the "synthesis exchange technique". Results show that at these P-T conditions, NH4+ partitions equally between phengite and coexisting fluid. Majorite was synthesized in multi-anvil experiments at P-T conditions of mantle transition zone and uppermost part of the lower mantle (18-23 GPa & 1450-1500 °C). Majorite as well as other run products were characterized by electron probe microanalysis (EPMA), XRPD with Rietveld refinement, vibrational spectroscopy (FTIR and Raman spectroscopy) and transmission electron microscopy (TEM). The effect of oxygen fugacity on controlling nitrogen speciation in the host mineral is elaborated here. It is shown that majoritic garnet can host N in different forms (N3- and NH4+) under different redox conditions by different mechanisms. The current PhD thesis therefore supports the argumentation that nitrogen can be introduced to the mantle through subduction, or in other words, that nitrogen in the mantle can be of recycled origin.

Description: Location of earthquakes is a primary task in seismology and microseismic monitoring, essential for almost any further analysis. Earthquake hypocenters can be determined by the inversion of arrival times of seismic waves observed at seismic stations, which is a non-linear inverse problem. Growing amounts of seismic data and real-time processing requirements imply the use of robust machine learning applications for characterization of seismicity. Convolutional neural networks have been proposed for hypocenter determination assuming training on previously processed seismic event catalogs. We propose an alternative machine learning approach, which does not require any pre-existing observations, except a velocity model. This is particularly important for microseismic monitoring when labeled seismic events are not available due to lack of seismicity before monitoring commenced (e.g., induced seismicity). The proposed algorithm is based on a feed-forward neural network trained on synthetic arrival times. Once trained, the neural network can be deployed for fast location of seismic events using observed P-wave (or S-wave) arrival times. We benchmark the neural network method against the conventional location technique and show that the new approach provides the same or better location accuracy. We study the sensitivity of the proposed method to the training dataset, noise in the arrival times of the detected events, and the size of the monitoring network. Finally, we apply the method to real microseismic monitoring data and show that it is able to deal with missing arrival times in efficient way with the help of fine tuning and early stopping. This is achieved by re-training the neural network for each individual set of picked arrivals. To reduce the training time we used previously determined weights and fine tune them. This allows us to obtain hypocenter locations in near real-time.

Description: A gravitational lensing event can occur when a gravitational field of, e.g., a cluster of galax- ies, distorts and magnifies the light from a distant, background galaxy that is almost in the same line of sight as the lensing mass. Among the ∼500 discovered gravitational lensed systems, the European Space Agency mission Gaia has detected at least one lensed image in ∼300 of these systems and released their astrometric parameters in EDR3. According to re- search, high accuracy VLBI observations to determine the relative positions between possible lensed images were carried out for 25 lensed systems. The lensed images refer to the various visible components in the field of view in the direction of the lensing system. Because these multiple lensed images of a source are typically a few arcseconds or less apart on the sky, they can be imaged on one map. This allows to determine the relative positions between them with an accuracy of tens of microarcseconds. This may enhance the study of the position differences between radio and optical, given that the multiple lensed images of an individual source are detected by both VLBI and Gaia. We report on the astrometric positions from historical VLBI observations, the results from the latest VLA observations, and the Gaia EDR3 results. We focus on the lensed system 1422+231, for which high-accuracy relative positions for the complete set of its lensed images are available from geodetic VLBI observations conducted in the 1990s. This study aims to understand the VLBI/Gaia position differences seen for 1422+231 and to potentially improve the modeling of the gravitationally lensed system, 1422+231, using more accurate astrometric positions from radio and optical.

Description: In some catchments, the distribution of annual maximum streamflow shows heavy tail behavior, meaning the occurrence probability of extreme events is higher than if the upper tail decayed exponentially. Neglecting heavy tail behavior can lead to an underestimation of the likelihood of extreme floods and the associated risk. Partly contradictory results regarding the controls of heavy tail behavior exist in the literature and the knowledge is still very dispersed and limited. To better understand the drivers, we analyze the upper tail behavior and its controls for 480 catchments in Germany and Austria over a period of more than 50 years. The catchments span from quickly reacting mountain catchments to large lowland catchments, allowing for general conclusions. We compile a wide range of event and catchment characteristics and investigate their association with an indicator of the tail heaviness of flood distributions, namely the shape parameter of the GEV distribution. Following univariate analyses of these characteristics, along with an evaluation of different aggregations of event characteristics, multiple linear regression models as well as random forests are constructed. A novel slope indicator, which represents the relation between the return period of flood peaks and event characteristics, captures the controls of heavy tails best. Variables describing the catchment response are found to dominate the heavy tail behavior, followed by event precipitation, flood seasonality and catchment size. The pre-event moisture state in a catchment has no relevant impact on the tail heaviness even though it does influence flood magnitudes.

Description: Statistical distributions of flood peak discharges often show heavy tail behavior, i.e., extreme floods are more likely to occur than would be predicted by commonly used distributions that have exponential asymptotic behavior. This heavy tail behavior may surprise flood managers and citizens, as human intuition tends to expect light tail behavior, and the heaviness of the tails is very difficult to predict, which may lead to unnecessarily high flood damage. Despite its high importance, the literature on the heavy tail behavior of flood distributions is rather fragmented. In this review, we provide a coherent overview of the processes causing heavy flood tails and the implications for science and practice. Specifically, we propose nine hypotheses on the mechanisms causing heavy tails in flood peak distributions related to processes in the atmosphere, the catchment and the river system. We then discuss to which extent the current knowledge supports or contradicts these hypotheses. We also discuss the statistical conditions for the emergence of heavy tail behavior based on derived distribution theory and relate them to the hypotheses and flood generation mechanisms. We review the degree to which the heaviness of the tails can be predicted from process knowledge and data. Finally, we recommend further research towards testing the hypotheses and improving the prediction of heavy tails.

Description: Effective flood risk management is highly relevant for advancing climate change adaptation. It needs to be based on risk modelling that considers the dynamics, complex interactions and feedbacks in human–flood systems. In this regard, we review recent advancements in understanding, quantifying and modelling changes in risk and its drivers. A challenge for integrating human behaviour in dynamic risk assessments and modelling is the combined consideration of qualitative and quantitative data. Advancements in this respect are (1) the compilation and analysis of comprehensive qualitative and quantitative data on flood risk changes in case studies following the paired event concept; (2) the integration of qualitative and quantitative data into socio-hydrological models using Bayesian inference; and (3) the coupling of hydrological flood risk models with behaviour models in socio-hydrological modelling systems. We recommend to further develop these approaches and use more such process-based, dynamic modelling also for large-scale flood risk analyses. These approaches are increasingly feasible due to significant improvements in computational power and data science.

Description: These short, informal newsletters, issued every month on approximately the first day of the month, are intended to keep IUGG Member National Committees informed about the activities of the IUGG Associations and actions of the IUGG Secretariat. Special issues are sometimes distributed mid-month as deemed appropriate. The content usually includes a synopsis of scientific meetings during the following three months in order to illustrate the disciplinary and geographical diversity of IUGG interests. E-Journals may be forwarded to those who will benefit from the information.

Description: Titanite is presented here as a tracer for reconstructing the mineralization history of Nb during magmatic and hydrothermal processes in the Fangcheng Nb deposit, central China. Three types of titanites with magmatic and hydrothermal origins are distinguished. The magmatic titanite (Ttn I), is generally wedge-shaped with larger grain size (up to 1.5 mm). The hydrothermal titanite, either overgrows the magmatic titanite as a thin rim (Ttn IIA), or occurs as bead-like clusters coexisting with hydrothermal albite, fluorite and/or Nb-rich oxides (Ttn IIB; anhedral and lesser than 200 μm). The Nb contents in the magmatic titanite (mean of 1.2 wt%), tend to be lower than in the hydrothermal types (mean of 1.7 wt%). The hydrothermal titanites show enrichment in Al2O3, F, Ta, Y, HREEs and Sn and depletion in TiO2, Zr, Hf, Th and LREEs relative to the magmatic titanite. Using Zr-in-titanite as a geothermometer, the magmatic titanite yields higher crystallization temperatures (mean of 760 °C) than the hydrothermal titanites (mean of 610 °C). Titanite U-Pb dating results reveal that the Fangcheng magmatic and hydrothermal titanites were formed at 870 Ma and 406 Ma, respectively. These results are consistent with the zircon U-Pb ages of this study and previous publication as well as the regional tectono-magmatic activities, indicating two discrete episodes of Nb mineralization events at Fangcheng. Isotopic data show distinctly lower εNd (t) values (−4.8 to −10.3) in the hydrothermal titanites as compared to the magmatic titanite (−0.6 to −4.1), confirming that these two generations of titanite involve distinct sources. Based on all results, we propose that the early magmatic titanite nucleated and crystallized in a high-T and Nb-rich alkaline magma during the Neoproterozoic. Early Paleozoic hydrothermal fluids partly replaced the magmatic titanite (Ttn I), forming the hydrothermal titanite rims (Ttn IIA). During this process, Nb and other HFSEs and REEs were re-activated and subsequently re-precipitated into secondary titanite (Ttn IIB), rutile, pyrochlore and euxenite.

Description: As recent developments regarding the increasing demand of renewable energy sources in the European energy sector demonstrate, the need for large-scale energy storage technologies intensifies. Since the availability of wind and photovoltaic energy are undergoing high fluctuations, excess energy has to be stored to be available at times of high energy demand. Implementation of pumped hydro power storage (PHS) plants in abandoned underground reservoirs are intensively studied as potential storage solution (e.g. Pickard, 2012), whereby open-pit lignite mines are also expected to contribute to this issue (Thema and Thema, 2019), but are hardly investigated, yet. PHS follows the concept of pumping and releasing water between two reservoirs located at different elevations. The success of energy storage by PHS in abandoned mines highly depends on the geo- and hydrochemical processes in the reservoirs and the surrounding porous media (Pujades et al., 2018). Oxidation of sulphur bearing minerals, especially of pyrite, might trigger the generation of Acid Mine Drainage (AMD; Akcil and Koldas, 2006), which can impact groundwater chemistry as well as slope stability, and further induce corrosion at critical technical infrastructure (Pujades et al., 2018). In the scope of the present study, we have investigated the major chemical reaction paths by numerical modelling to conceptualise comprehensive reactive transport simulations for environmental risk assessments. For that purpose, we considered available research findings from studies on the Lusatian and Rhenish lignite mining areas, and applied these to other European mining sites. Calcite buffering, mineral dissolution-precipitation balances, heavy metal contamination as well as mixing processes between the potential reservoirs and groundwater have been taken into account. In summary, geochemical impacts potentially occurring with PHS operation under hydrochemical boundary conditions representative for European open-pit lignite mines were investigated and quantified.

Description: The rewetting of peatlands is a promising measure to mitigate greenhouse gas (GHG) emissions by preventing the further mineralization of the peat soil through aeration. In coastal peatland, the rewetting with brackish water can increase the GHG mitigation potential by the introduction of sulfate, a terminal electron acceptor (TEA). Sulfate is known to lower the CH4 production and thus, its emission by favoring the growth of sulfate-reducers, which outcompete methanogens for substrate. The data contain porewater variables such as pH, electrical conductivity (EC) and sulfate, chloride, dissolved CO2 and CH4 concentrations, as well as absolute abundances of methane- and sulfate-cycling microbial communities. The data were collected in spring and autumn 2019 after a storm surge with brackish water inflow in January 2019. Field sampling was conducted in the nature reserve Heiligensee and Hütelmoor in North-East Germany, close to the Southern Baltic Sea coast. We took peat cores using a Russian peat corer in addition to pore water diffusion samplers and plastic liners (length: 60cm; inner diameter 10 cm) at four locations along a transect from further inland towards the Baltic Sea. We wanted to compare the soil and pore water geochemistry as well as the microbial communities after the brackish water inflow to the common freshwater rewetting state. Pore water was extracted using pore water suction samplers in the lab and environmental variables were quantified with an ICP. Microbial samples were sampled from the peat core using sterile equipment. We used quantitative polymerase chain reaction (qPCR) to characterize pools of DNA and cDNA targeting total and putatively active bacteria and archaea. qPCR was performed on key functional genes of methane production (mcrA), aerobic methane oxidation (pmoA) and sulfate reduction (dsrB) in addition to the 16S rRNA gene for the absolute abundance of total prokaryotes. Furthermore, we retrieved soil plugs to determine the concentrations and isotopic signatures of dissolved trace gases (CO2/DIC and CH4) in the pore water.

Description: The nature of Earth's earliest crust and crustal processes remain unresolved questions in Precambrian geology. While some hypotheses suggest that plate tectonics began in the Hadean, others suggest that the Hadean was characterized by long-lived protocrust and an absence of significant plate tectonic processes. Recently proposed trace-element proxies for the tectono-magmatic settings in which zircons formed are a relatively novel tool to understand crustal processes in the past. Here, we present high-spatial resolution zircon trace and rare earth element geochemical data along with Hf and O isotope data of a new location with Hadean materials, 4.1–3.3 Ga detrital zircons from the 3.31 Ga Green Sandstone Bed, Barberton Greenstone Belt. Together, the hafnium isotope and trace element geochemistry of the detrital zircons record a major transition in crustal processes. Zircons older than 3.8 Ga show evidence for isolated, long-lived protocrust derived by reworking of relatively undepleted mantle sources with limited remelting of surface-altered material. After 3.8 Ga, Hf isotopic evidence for this protocrust is muted while relatively juvenile source components for the zircon's parental magmas and flux-like melting signatures become more prominent. This shift mirrors changes in Hf isotopes and trace element geochemistry in other Archean terranes between ∼3.8 and 3.6 Ga and supports the notion that the global onset of pervasive crustal instability and recycling—A possible sign for mobile-lid tectonics—Occurred in that time period.

Description: Porphyry copper deposits represent very large differentiated hydrothermal alteration footprints resulting from convective fluid circulation. Hyperspectral imaging spectroscopy can provide a rapid and effective tool for systematic mapping of mineralogical footprints of many mineral systems including the porphyry copper deposits at local to regional scales. To demonstrate the capability of airborne hyperspectral imagery in deposit scale exploration, a portion of the HyMap data collected over a porphyry copper deposit named Shadan in eastern Iran was selected. By using a combination of spectral unmixing techniques and feature extraction methods, a large suite of alteration minerals was detected over this deposit. This includes white mica abundance, composition, and crystallinity, kaolinite abundance and crystallinity, ferric oxide content and composition, together with jarosite, chlorite-epidote, amphiboles, and tourmaline abundances and distribution. The results of this study indicate that airborne hyperspectral imagery and their mineral map products can be used to delineate porphyry copper systems and target the most promising areas for further exploration activities.

Description: Seismology, like many scientific fields, e.g., music information retrieval and speech signal pro- cessing, is experiencing exponential growth in the amount of data acquired by modern seismo- logical networks. In this thesis, I take advantage of the opportunities offered by "big data" and by the methods developed in the areas of music information retrieval and machine learning to predict better the ground motion generated by earthquakes and to study the properties of the surface layers of the Earth. In order to better predict seismic ground motions, I propose two approaches based on unsupervised deep learning methods, an autoencoder network and Generative Adversarial Networks. The autoencoder technique explores a massive amount of ground motion data, evaluates the required parameters, and generates synthetic ground motion data in the Fourier amplitude spectra (FAS) domain. This method is tested on two synthetic datasets and one real dataset. The application on the real dataset shows that the substantial information contained within the FAS data can be encoded to a four to the five-dimensional manifold. Consequently, only a few independent parameters are required for efficient ground motion prediction. I also propose a method based on Conditional Generative Adversarial Networks (CGAN) for simulating ground motion records in the time-frequency and time domains. CGAN generates the time-frequency domains based on the parameters: magnitude, distance, and shear wave velocities to 30 m depth (VS30). After generating the amplitude of the time-frequency domains using the CGAN model, instead of classical conventional methods that assume the amplitude spectra with a random phase spectrum, the phase of the time-frequency domains is recovered by minimizing the observed and reconstructed spectrograms. In the second part of this dissertation, I propose two methods for the monitoring and characterization of near-surface materials and site effect analyses. I implement an autocorrelation function and an interferometry method to monitor the velocity changes of near-surface materials resulting from the Kumamoto earthquake sequence (Japan, 2016). The observed seismic velocity changes during the strong shaking are due to the non-linear response of the near-surface materials. The results show that the velocity changes lasted for about two months after the Kumamoto mainshock. Furthermore, I used the velocity changes to evaluate the in-situ strain-stress relationship. I also propose a method for assessing the site proxy "VS30" using non-invasive analysis. In the proposed method, a dispersion curve of surface waves is inverted to estimate the shear wave velocity of the subsurface. This method is based on the Dix-like linear operators, which relate the shear wave velocity to the phase velocity. The proposed method is fast, efficient, and stable. All of the methods presented in this work can be used for processing "big data" in seismology and for the analysis of weak and strong ground motion data, to predict ground shaking, and to analyze site responses by considering potential time dependencies and nonlinearities.

Description: The Environmental Mapping and Analysis Program (EnMAP) is a spaceborne German hyperspectral satellite mission that aims at monitoring and characterizing the Earth's environment on a global scale. The mission is now ready to start with the sensor being by end of 2021 in Flight Acceptance Review, ready to be shipped to the launch pad in early 2022. This paper presents first an update of the mission status with recent activities and developments from the space and the ground segment. Then, an update of selected highlights of the science segment activities at launch phase are presented including preparation and if possible early results for the validation of EnMAP products, updates on EnMAP science algorithms (EnMAP-Box) developed at GFZ, online education initiative (HYPERedu), and further mission support activities such as background mission.

Description: Water is one of the most essential substances on Earth as it occurs in all three thermodynamic phases both in the atmosphere and the surface: solid water in terms of snow and ice grains, liquid water enclosed in-between ice crystals and leaves of vegetation, and gaseous water forming the water vapor in the atmosphere. The different phases of water control large amounts of the environmental energy cycle and a quantitative mapping on a global scale is of particular importance as it provides a valuable input to climate models and helps to understand underlying processes. The three phases of water show subtle differences in absorption shape in the optical range of the solar spectrum, so that a quantitative mapping requires high-resolution measurements of solar radiation reflected from Earth's surface. The technique of imaging spectroscopy provides such measurements, but has been almost entirely applied to small local scales based on airborne sensors. However, a new generation of orbital missions, including the Italian Hyperspectral Precursor of the Application Mission (PRISMA), NASA’s Earth Surface Mineral Dust Source Investigation (EMIT), the German Environmental Mapping and Analysis Program (EnMAP), ESA's Copernicus Hyperspectral Imaging Mission (CHIME), and NASA’s Surface Biology and Geology (SBG) designated observable, is expected to deliver high-resolution data both on a global scale and daily basis. This requests for independently applicable retrieval algorithms including a rigorous quantification of uncertainties. In this context, this thesis presents two new spectroscopic retrieval methods to quantify the three phases of water from space, which are aligned with future instrument characteristics, adapted to an increased atmospheric path as well as to a different ground sampling distance. Both algorithms use the optimal estimation formalism that assumes Gaussian error distribution and leverages prior knowledge as well as measurement noise in an inversion scheme that also produces posterior uncertainty estimates. The first method couples atmospheric radiative transfer simulations from the MODTRAN code to a surface reflectance model based on the Beer-Lambert law. A unique coupling of the 3D Hyperspectral Simulation of Canopy Reflectance (HySimCaR) model and the EnMAP end-to-end Simulation tool (EeteS) is exploited for a sensitivity analysis of estimated vegetation liquid water content. Furthermore, the retrieved values are validated with concurrent field measurements of canopy water content. The second algorithm is based on a simultaneous retrieval of atmosphere and surface state and exploits statistical relationships between reflectance spectra and additional surface parameters to estimate their most probable quantities. Retrieved snow and ice properties are investigated based on a sensitivity analysis and validated with laboratory and field measurements from the Greenland Ice Sheet. Finally, the applicability of the proposed methods to forthcoming spaceborne imaging spectrometers is demonstrated on the example of PRISMA cryosphere observations by providing retrieval maps of surface liquid water and ice grain size as well as associated retrieval uncertainties. The results from this thesis show that spaceborne imaging spectroscopy permits improved atmospheric water vapor estimations, facilitates a prediction of vegetation drought stress and wildfire potential, and contributes to the understanding of biophysical processes on Earth’s Ice Sheets in the context of climate change. Concurrently, three key aspects have been identified to be of particular importance for globally applicable retrieval algorithms: (i) considering topographic characteristics, such as surface slope and aspect as well as sky view factor and shadow fraction, (ii) integrating directional effects depending on illumination and observation conditions, (iii) accounting for mixed pixels by determining influences from background reflectance and fractional cover. Overall, this thesis demonstrates that upcoming launches of several imaging spectroscopy missions open new perspectives in regularly monitoring and mapping atmosphere and surface properties including the three phases of water on a global scale. These maps will provide a valuable input to the modeling of biological and physical processes that help to better understand climate change and to predict and adapt to its socioeconomic consequences.

Description: Wasser ist eine der wichtigsten Substanzen auf der Erde, da es in allen drei thermodynamischen Phasen sowohl in der Atmosphäre als auch auf der Oberfläche vorkommt: festes Wasser in Form von Schnee und Eiskörnern, flüssiges Wasser zwischen Eiskristallen und als Bestandteil von Pflanzenblättern sowie gasförmiges Wasser, das den Wasserdampf in der Atmosphäre bildet. Die verschiedenen Wasserphasen steuern große Teile des ökologischen Energiekreislaufes, so dass eine quantitative Kartierung auf globaler Ebene von besonderer Bedeutung ist. Sie leistet außerdem einen wertvollen Beitrag zur Klimamodellierung und hilft, die zugrunde liegenden Prozesse besser zu verstehen. Die drei Phasen des Wassers weisen feine Unterschiede in ihrer Absorptionsform im optischen Bereich des solaren Spektrums auf, so dass eine quantitative Bestimmung hochauflösende Messungen der von der Erdoberfläche reflektierten Sonnenstrahlung erfordert. Die Technik der abbildenden Spektroskopie liefert solche Messungen, wurde aber bisher fast ausschließlich auf der Grundlage von flugzeuggestützten Sensoren auf kleinen lokalen Skalen angewandt. Eine neue Generation von Weltraummissionen, darunter die italienische Hyperspectral Precursor of the Application Mission (PRISMA), die Earth Surface Mineral Dust Source Investigation (EMIT) der NASA, das deutsche Environmental Mapping and Analysis Program (EnMAP), die Copernicus Hyperspectral Imaging Mission (CHIME) der ESA und das NASA Surface Biology and Geology (SBG) Observable, soll jedoch hochauflösende Daten sowohl auf globaler Ebene als auch auf täglicher Basis liefern. Dies erfordert unabhängig anwendbare Kartierungsalgorithmen einschließlich einer präzisen Quantifizierung der Unsicherheiten. In diesem Zusammenhang werden in dieser Arbeit zwei neue spektroskopische Methoden zur Quantifizierung der drei Phasen von Wasser aus dem Weltraum vorgestellt, die auf die zukünftigen Instrumentencharakteristika abgestimmt sind und sowohl an einen längeren Weg der Strahlung durch die Atmosphäre als auch an eine andere räumliche Auflösung auf dem Erdboden angepasst sind. Beide Algorithmen verwenden den Formalismus der Maximum-a-posteriori-Schätzung, der von einer Gauß'schen Fehlerverteilung ausgeht und sowohl Vorwissen als auch Messrauschen in einem Inversionsschema nutzt, das zusätzlich a posteriori Unsicherheitsschätzungen liefert. Bei der ersten Methode werden atmosphärische Strahlungstransfersimulationen aus dem MODTRAN-Code mit einem auf dem Beer-Lambert-Gesetz basierenden Oberflächenreflexionsmodell gekoppelt. Eine einzigartige Kopplung des 3D Hyperspectral Simulation of Canopy Reflectance (HySimCaR) Systems und des EnMAP end-to-end Simulationstools (EeteS) wird für eine Sensitivitätsanalyse des geschätzten Flüssigwassergehalts von Vegetation genutzt. Außerdem werden die ermittelten Werte mit gleichzeitigen Feldmessungen des Wassergehalts von Vegetationskronen validiert. Der zweite Algorithmus basiert auf der simultanen Ermittlung des Zustands von Atmosphäre und Oberfläche und nutzt statistische Beziehungen zwischen Reflexionsspektren und zusätzlichen Oberflächenparametern, um deren wahrscheinlichste Größen zu schätzen. Die ermittelten Schnee- und Eiseigenschaften werden auf der Grundlage einer Sensitivitätsanalyse untersucht und mit Labor- und Feldmessungen vom grönländischen Eisschild validiert. Abschließend wird die Anwendbarkeit der vorgeschlagenen Methoden auf die kommenden weltraumgestützten abbildenden Spektrometer am Beispiel von PRISMA Aufnahmen von Schnee- und Eisflächen demonstriert, indem Karten von Flüssigwasser und Eiskorngröße sowie die damit verbundenen Unsicherheiten dargestellt werden. Die Ergebnisse dieser Arbeit zeigen, dass die weltraumgestützte abbildende Spektroskopie verbesserte Abschätzungen des atmosphärischen Wasserdampfs ermöglicht, die Vorhersage von Pflanzenstress und Waldbrandgefahr erleichtert und zum Verständnis der biophysikalischen Prozesse auf den Eisschilden der Erde im Zusammenhang mit dem Klimawandel beiträgt. Gleichzeitig werden drei Schlüsselaspekte identifiziert, die für global anwendbare Kartierungsalgorithmen von besonderer Bedeutung sind: (i) die Berücksichtigung topographischer Merkmale, wie z.B. Oberflächenneigung und -aspekt sowie Himmelslichtquotient und Schattenanteil, (ii) die Integration von Richtungseffekten in Abhängigkeit von Beleuchtungs- und Beobachtungsbedingungen, (iii) die Berücksichtigung von Mischpixeln durch die Bestimmung von Einflüssen der Hintergrundreflexion und des Bedeckungsgrades. Insgesamt zeigt diese Arbeit, dass die bevorstehenden Starts mehrerer abbildender Spektroskopiemissionen neue Perspektiven für die regelmäßige Überwachung und Kartierung von Atmosphären- und Oberflächeneigenschaften, einschließlich der drei Phasen des Wassers, auf globaler Ebene eröffnen. Diese Karten werden einen wertvollen Beitrag zur Modellierung biologischer und physikalischer Prozesse leisten, die zu einem besseren Verständnis des Klimawandels und zur Vorhersage und Anpassung an seine sozioökonomischen Folgen beiträgt. de

Description: It is not well known how much Earth’s surface temperature will change over the next few millennia as a result of increasing atmospheric CO2 concentrations. This is because we still have a limited understanding of many slow climate feedback mechanisms activated by climate change that will become important in the future. Most climate models project eventual global warming of 3–4°C for doubled CO2 concentration but exclude many slow climate feedbacks, such as shrinking ice sheets. The distant (geologic) past provides additional clues about the future because the climate system and all of its feedbacks were in equilibrium with naturally elevated CO2. Using up-to-date geologic information of the last 50 million years, we find that Earth’s climate history is best described by a switch from a moderate sensitivity, close to that found in climate models, to a much higher sensitivity in the last 3 million years. If Earth behaves the same way today as it has done in the past, melting ice sheets, natural aerosols, and shifting vegetation patterns will slowly continue to raise global warming above the 2°C target during the next few thousand years even if the human contribution does not increase any further.

Description: Despite advanced seismological techniques, automatic source characterization for microseismic earthquakes remains difficult and challenging since current inversion and modelling of high-frequency signals are complex and time consuming. For real-time applications such as induced seismicity monitoring, the application of standard methods is often not fast enough for true complete real-time information on seismic sources. In this paper, we present an alternative approach based on recent advances in deep learning for rapid source-parameter estimation of microseismic earthquakes. The seismic inversion is represented in compact form by two convolutional neural networks, with individual feature extraction, and a fully connected neural network, for feature aggregation, to simultaneously obtain full moment tensor and spatial location of microseismic sources. Specifically, a multibranch neural network algorithm is trained to encapsulate the information about the relationship between seismic waveforms and underlying point-source mechanisms and locations. The learning-based model allows rapid inversion (within a fraction of second) once input data are available. A key advantage of the algorithm is that it can be trained using synthetic seismic data only, so it is directly applicable to scenarios where there are insufficient real data for training. Moreover, we find that the method is robust with respect to perturbations such as observational noise and data incompleteness (missing stations). We apply the new approach on synthesized and example recorded small magnitude (M ≤ 1.6) earthquakes at the Hellisheiði geothermal field in the Hengill area, Iceland. For the examined events, the model achieves excellent performance and shows very good agreement with the inverted solutions determined through standard methodology. In this study, we seek to demonstrate that this approach is viable for microseismicity real-time estimation of source parameters and can be integrated into advanced decision-support tools for controlling induced seismicity

Description: The constant increase of geodetic instrumentation over the past decades enables us to not only detect ever smaller tectonic signals but also to monitor their evolution in time and space. We present spatial and temporal slip variations observed on a fault affected by a large, intermediate-field earthquake: the 2015 Mw7.2 Sarez, Central Pamir, earthquake ruptured the sinistral, NE-trending Sarez-Karakul fault system. 120–170 km North of the main rupture, the thin-skinned, E-trending Pamir thrust system bounding the Pamir to the North was co-seismically activated. We derived co-seismic offsets and post-seismic rates observed by two dense, high-rate Global Positioning System (GPS) profiles crossing the Pamir thrust system at different longitudes. The continuous GPS observations of the western profile focus on the dextral, NW-striking Aramkungey fault segment that connects two thrust faults with opposite dip. We compare inter-, co- and post-seismic displacement rates by complementing the continuous data with survey-mode GPS data and East rates derived from satellite radar interferometric displacement time-series. All the GPS stations were shifted toward the epicenter against the direction of the interseismic load with an increased gradient in the Aramkungey fault segment. During the postseismic stage, the fault-parallel and fault-perpendicular rates were affected differently, suggesting gradual re-locking of the Aramkungey fault after its unlocking by right-lateral co-seismic slip.

Description: Motional induction describes the induction of electric currents through charged particles moving perpendicular to an ambient magnetic field. A well-known device that uses motional induction to induce electric currents is the bicycle dynamo. The induction of electric currents in the ocean due to the motion of saltwater within the ambient geomagnetic field is, by contrast, lesser-known; this phenomenon is called the ocean-dynamo effect which indicates the similarity of both phenomena. The electromagnetic field signals emitted by ocean-dynamo induced electric currents are primarily sensitive to three factors: 1. the number of moving charged particles, 2. the magnetic field strength of the ambient field, and 3. the velocity with which the particles move perpendicular to said magnetic field. The amount of electrically charged particles in the seawater, a saline solution, is measured with the electrical seawater conductivity σ. σ is determined by the saline solution's chemical equilibrium, which in return is predominantly defined by the physical properties of seawater temperature and salinity. Thus, changes in the spatial distribution of seawater temperature and salinity cause changes in the spatial distribution of electrical seawater conductivity, which in return affect the ocean-dynamo signals. In theory, ocean-dynamo signals are therefore suitable for ocean observation applications. Out of all ocean-induced electromagnetic signals, signals induced by ocean tides play a unique role. The signatures of the periodic tidal flow are the only ocean-dynamo signals that have been successfully observed in magnetometer observations, space-borne and land-based. In addition to the proven measurability, the signals are also modelled with sufficient accuracy so that, on a global scale, observed tidal ocean-dynamo signatures agree well with model predictions. These two preconditions allow for an investigation of the relationship between ocean dynamics and tidal ocean-dynamo signals, a much-needed advancement towards practical ocean observation applications. In the past, sensitivity studies of tidal ocean-dynamo signals have focused mainly on changes on long time scales. By contrast, the present cumulative thesis examines the influence of ocean dynamics on tidal ocean-dynamo signals on short and intermediate time scales. In particular, it investigates the mechanisms and effects of ocean dynamics and recent seawater temperature and salinity changes on tidal ocean-dynamo signals. Furthermore, it investigates the detectability and measurability of short-term variations of said signals in magnetometer observations. Out of the presented three research studies, the first is a model-based characterization of tidal ocean-dynamo amplitude variations attributed to the El Niño/Southern Oscillation (ENSO). The study shows that tidal ocean-dynamo signal changes precede the onset of warm and cold ENSO phases and attributes these findings to the underlying oceanic processes. Furthermore, the study provides an assessment of the measurability of ENSO-induced tidal ocean-dynamo amplitude variations. The second study covers a time series analysis of modeled tidal ocean-dynamo amplitudes on a global scale. Here, the amplitudes were modeled based on existing oceanic seawater temperature and salinity observations. Based on the analysis of the underlying in-situ data, the study assesses recent developments in signal amplitudes to resolve a conflict between existing model-based sensitivity studies. Furthermore, the study identifies the heightened sensitivity of coastal tidal ocean-dynamo signals and provides a physical explanation for this fact. The third study focuses on local ocean phenomena and analyses time series of coastal island magnetometer observations. It presents evidence for seasonal amplitude variations and trends in amplitudes and phases of tidal ocean-dynamo signals. The advancements in the field contribute to the transition from retrospective or model-based analysis to an actual inference of the oceanic temperature and salinity dynamics from magnetometer observations.

Description: Cubic CaSiO3 perovskite is a major phase in subducted oceanic crust, where it forms at a depth of about 550 kilometres from majoritic garnet1,2,28. However, its rheological properties at temperatures and pressures typical of the lower mantle are poorly known. Here we measured the plastic strength of cubic CaSiO3 perovskite at pressure and temperature conditions typical for a subducting slab up to a depth of about 1,200 kilometres. In contrast to tetragonal CaSiO3, previously investigated at room temperature3,4, we find that cubic CaSiO3 perovskite is a comparably weak phase at the temperatures of the lower mantle. We find that its strength and viscosity are substantially lower than that of bridgmanite and ferropericlase, possibly making cubic CaSiO3 perovskite the weakest lower-mantle phase. Our findings suggest that cubic CaSiO3 perovskite governs the dynamics of subducting slabs. Weak CaSiO3 perovskite further provides a mechanism to separate subducted oceanic crust from the underlying mantle. Depending on the depth of the separation, basaltic crust could accumulate at the boundary between the upper and lower mantle, where cubic CaSiO3 perovskite may contribute to the seismically observed regions of low shear-wave velocities in the uppermost lower mantle5,6, or sink to the core–mantle boundary and explain the seismic anomalies associated with large low-shear-velocity provinces beneath Africa and the Pacific7,8,9.

Description: Life can be found even in extreme environments, e.g., near black smokers on the ocean floor at temperatures up to ca. 120 °C and hydrostatic pressures of 40 MPa. To maintain vital reactions under these hostile conditions, extremophiles are interacting with the surrounding geochemical system. In this context, the stabilities of the essential energy-storing adenosine triphosphate (ATP) and adenosine diphosphate (ADP) are of fundamental importance because reactions involving adenosine phosphates constrain the conditions at which carbon-based life can exist and might be also crucial information for the search of extra-terrestrial life. Adenosine phosphates react by non-enzymatic hydrolysis, which is kinetically enhanced at high temperatures. If these abiotic hydrolysis processes are too rapid, they will most likely prevent metabolisms from relying on ATP. Here, we report on an approach used in experimental geochemistry, i.e., in situ Raman spectroscopic analyses of a fluid phase at high temperature using a hydrothermal diamond anvil cell. This combination allowed the investigation of the hydrolysis of Adenosine Tri-Phosphate (ATP) in aqueous solution at pH 3 and 7 and at temperatures of 80, 100 and 120 °C, extending the so far measured temperature range substantially. We observed Arrhenian behaviour over this temperature interval. The rate constants at 120 °C were 4.34 × 10−3 s−1 at pH 3 and 2.91 × 10−3 s−1 at pH 7. This corresponds to ATP half-lives of a few minutes. These high decomposition rates of ATP suggest that organisms must have developed a mechanism to counteract this fast reaction at high temperatures to maintain the vital processes.

Description: The continued warming of the Arctic could release vast stores of carbon into the atmosphere from high-latitude ecosystems, especially from thawing permafrost. Increasing uptake of carbon dioxide (CO2) by vegetation during longer growing seasons may partially offset such release of carbon. However, evidence of significant net annual release of carbon from site-level observations and model simulations across tundra ecosystems has been inconclusive. To address this knowledge gap, we combined top-down observations of atmospheric CO2 concentration enhancements from aircraft and a tall tower, which integrate ecosystem exchange over large regions, with bottom-up observed CO2 fluxes from tundra environments and found that the Alaska North Slope is not a consistent net source nor net sink of CO2 to the atmosphere (ranging from −6 to +6 Tg C yr−1 for 2012–2017). Our analysis suggests that significant biogenic CO2 fluxes from unfrozen terrestrial soils, and likely inland waters, during the early cold season (September–December) are major factors in determining the net annual carbon balance of the North Slope, implying strong sensitivity to the rapidly warming freeze-up period. At the regional level, we find no evidence of the previously reported large late-cold-season (January–April) CO2 emissions to the atmosphere during the study period. Despite the importance of the cold-season CO2 emissions to the annual total, the interannual variability in the net CO2 flux is driven by the variability in growing season fluxes. During the growing season, the regional net CO2 flux is also highly sensitive to the distribution of tundra vegetation types throughout the North Slope. This study shows that quantification and characterization of year-round CO2 fluxes from the heterogeneous terrestrial and aquatic ecosystems in the Arctic using both site-level and atmospheric observations are important to accurately project the Earth system response to future warming.

Description: In the view of increasing water demands in agriculture, efficient water use is a key factor in potato production. The aim of this study was to compare two deficit (80% and 90%) and one abundant (120%) gun sprinkler irrigation levels with the longtime used irrigation level of a farmer (100%). Irrigation was supplied during the 2021 growing season on a loamy sand site in Mecklenburg–Western Pomerania, Germany. Yield and tuber quality of the high-amylopectin potato (HAPP) variety “Waxy/Henriette” were assessed in a three-grade tuber size distribution. Five economic indicators were used to assess the suitability of the investigated irrigation levels to secure economic responses. Yield and starch yield did not significantly differ between the 90% (561.1 dt ha−1 and 102.0 dt ha−1) and the 100% irrigation levels (559.1 dt ha−1 and 102.3 dt ha−1), with total production increasing by 2.0 dt ha−1 and starch production decreasing by 0.4 dt ha−1 at the 90% irrigation level. Tuber lesions decreased the economic responses at all irrigation levels. Potentially, 87,469 m3 of irrigation water (125.8 m3 ha−1) could have been saved on the loamy sand starch potato sites of the local farm (695.3 ha) in 2021.

Description: Oil-bearing fluid inclusions (FIs) are a widespread phenomenon in veins and vugs of petroleum systems. The occluded oils provide invaluable information on the composition and physical as well as chemical properties of these oils and on geochemical processes within the respective petroleum system. A specific advantage of fluid inclusions is that the trapped oils are protected against secondary processes impacting the petroleum system such as water washing, biodegradation, migration and drill mud contamination and, thus, fluid inclusions provide information on the original pristine petroleum charge. From an analytical point of view generally gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-MS) and gas chromatography-isotope ratio mass spectrometry (GC-IRMS) are applied to analyze the aliphatic and aromatic compounds of the FI oils and to solve the geological issues of the petroleum system. Less is known about co-occurring nitrogen, sulfur and oxygen (NSO)-containing compounds. NSO-compounds are components, which, due to their polarity, are prone to physical, chemical and biological interaction processes and therefore, are promising compounds for unravelling secondary alteration processes in petroleum systems. To explore the potential of the NSO fraction in FI oil research, a relatively new analytical technique has been applied here: the Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) in combination with Atmospheric Pressure Photoionization in positive ion mode (APPI (+)) and Electrospray Ionization in negative ion mode (ESI (–)). The technique allows an extension of the analytical window of NSO components into the high molecular weight compound range. Due to the high sensitivity of the FT-ICR-MS it was first necessary to develop an extremely thorough FI clean-up and sample preparation method. Then, in a second step, the application potential of the NSO fractions measured by FT-ICR-MS for FI research was explored in two case studies addressing the charge and leakage history in petroleum systems and petroleum fractionation during oil primary migration. In these studies, the data of the newly introduced FT-ICR-MS technique are combined in a multi-analytical approach with microscopy, GC-MS and GC-IRMS data. Due to the low compound yield in FIs, the FI compound inventory can easily be contaminated by compounds from outer surfaces and a thorough cleaning protocol is a prerequisite for FI oil research. Previous clean-up methods for host minerals are not suitable for the FT-ICR-MS analysis, and a more rigorous clean-up method had to be developed. For this purpose, two fluorite and two quartz samples, containing a high number of oil FIs, were selected to develop an improved clean up method for host minerals using Soxhlet and sonication apparatus with various inorganic and organic solvents used in sequence. Although not all contaminants from surrounding host mineral surfaces could be eliminated, the procedure enabled the external contaminants to be identified and thus to assess the level of contamination of individual NSO-compound classes. This allows a well-considered interpretation of the FT-results of FI samples including their contamination levels, especially for compounds measured in the APPI (+) but also in the ESI (–) mode. Furthermore, it was demonstrated that previously established NSO parameters developed for crude oils and sediment extracts can also be utilized in FI oil research. In the first case study the oil charge and leakage history of the Skarv field A reservoir segment in the Haltenbanken region offshore Norway was elucidated. FI oils in quartz cements from the Jurassic Garn and Tilje Formation (Fm) sandstones representing the initial oil charge were compared to the corresponding adsorbed (Ad) residual oils on host mineral surfaces representing the current reservoir oil filling. The comprehensive biomarker, stable carbon isotope and NSO-compound analyses shows that both FI oils from the Garn and Tilje Fm and the Ad oil from the Tilje Fm derive from a similar source of similar age, whereas the Ad oil from the Garn Fm shows a lower maturity level and differences in facies indicators. The similar geochemical signals for the FI oils from the Tilje and Garn Fm point to a first charging from the same source rock most likely the late-Jurassic/earliest-Cretaceous Spekk Fm. The fact that the Ad oil in the Tilje Fm is similar to the respective FI oil indicates that the Tilje Fm was charged only once. In contrast, differences between the FI and Ad oils in the Garn Fm suggest that first charge oil has leaked and was replenished by a later oil charge presumably from another less mature source of the Spekk Fm. The NSO data confirm the similarity between the FI oils of the Garn and Tilje Fm. However, due to very low NSO-compound contents in the Ad oils a comparison between the FI and Ad oil NSO-compounds for the two reservoirs using FT-ICR-MS was not possible in this case. In the second case study, the fractionation of hydrocarbon (HC) and NSO-compounds during oil primary migration of the Hosszúhetény Calcareous Marl Formation (HCMF) in the Mecsek Mountains area (Hungary) was revealed, where FI oils represent expelled fluids and extracts from the HCMF source rock (SR) represent retained bitumen as verified by the similar biomarker proxies and stable carbon isotope data. The comparison of FT-ICR-MS results from the FI oils and SR extracts shows that O1, N1, N1O1 and S1O1 compound classes are preferentially retained in the SR bitumen, while S1 compounds are preferentially expelled from SR. O2 and HC compounds seem to show at first glance no preference. In addition, a deeper look into the FT-NSO-compound classes reveals that compounds with a higher aromaticity are preferentially retained in SRs, which is especially true for compounds with a high number of double bond equivalents (DBEs) in the lower carbon number range. This indicates shorter alkyl side chains attached to the aromatic structures and thus a less pronounced shielding effect. Overall, this study provides significant indication that HC and NSO-compound fractionation during primary migration is influenced by the different functional groups with their associated polarities and by their molecular shape and size especially the degree of aromaticity.

Description: Ölhaltige Flüssigkeitseinschlüsse sind ein weit verbreitetes Phänomen in Gängen und Klüften von Erdölsystemen. Die eingeschlossenen Öle liefern wertvolle Informationen über die Zusammensetzung und physikalischen wie chemischen Eigenschaften dieser Öle sowie über geochemische Prozesse im entsprechenden Erdölsystem. Ein besonderer Vorteil von Flüssigkeitseinschlüssen besteht darin, dass die eingeschlossenen Öle vor verändernden sekundären Prozessen wie z. B. der Wasserauswaschung von Komponenten, dem biologischen Abbau, der Migration von Ölen und der Verunreinigung durch Bohrschlamm geschützt sind. Flüssigkeitseinschlüsse können damit unverfälschte Informationen über die ursprüngliche Erdölfüllung liefern. Aus analytischer Sicht werden im Allgemeinen Techniken wie die Gaschromatographie (mit einem Flammenionisationsdetektor, GC-FID), die Gaschromatographie-Massenspektrometrie (GC-MS) und die Gaschromatographie-Isotopenverhältnis-Massenspektrometrie (GC-IRMS) eingesetzt, um die aliphatischen und aromatischen Verbindungen der Öle in Flüssigkeitseinschlüssen zu analysieren und die geologischen Fragestellungen des Erdölsystems zu beantworten. Im Gegensatz zu aliphatischen und aromatischen Verbindungen ist nur sehr wenig über Stickstoff, Schwefel und Sauerstoff (NSO) enthaltende Verbindungen bekannt. Bei den NSO-Verbindungen handelt es sich um Komponenten, die aufgrund ihrer Polarität stark dazu neigen, physikalische, chemische und biologische Wechselwirkungsprozesse mit der Umgebung einzugehen. Sie sind daher vielversprechende Verbindungen, um anhand der Veränderung ihrer relativen Zusammensetzung sekundäre Alterationsprozesse in Erdölsystemen aufzudecken. Um das Potenzial der NSO-Komponenten in der Erforschung von Ölflüssigkeitseinschlüssen zu untersuchen, wird in dieser Arbeit eine relativ neue Analysetechnik angewandt: die Fourier-Transform-Ionen Zyklotron Resonanz-Massenspektrometrie (FT-ICR-MS) in Kombination mit Atmosphärendruck-Photoionisation im positiven Ionenmodus (APPI (+)) und Elektrospray-Ionisation im negativen Ionenmodus (ESI (–)). Gleichzeitig ermöglicht diese Technik eine Erweiterung des Analysefensters von NSO-Komponenten in den vorher nicht erfassten hochmolekularen Bereich. Aufgrund der hohen Empfindlichkeit des FT-ICR-MS ist es zunächst erforderlich, eine neue Reinigungs- und Probenvorbereitungsmethode für die Untersuchung von Flüssigkeitseinschlüssen zu entwickeln. In einem zweiten Schritt wird das Anwendungspotenzial der mit der FT-ICR-MS Technik bestimmten NSO Komponenten in zwei Fallstudien untersucht, die sich mit der Befüllungs- und Leckagegeschichte in einem Erdölsystem und der Erdölfraktionierung während der primären Ölmigration befassen. In diesen Studien werden die Daten der neu eingeführten FT-ICR-MS Methode mit herkömmlichen Daten der Flüssigkeitseinschlussanalyse wie der Mikroskopie, GC-MS und GC-IRMS kombiniert. Aufgrund der in der Regel geringeren Menge an Verbindungen in Flüssigkeitseinschlüssen kann diese Zusammensetzung leicht durch Komponenten von der äußeren Oberfläche des Wirtsminerals verunreinigt werden. Aus diesem Grund ist ein gründliches Reinigungsprotokoll eine zentrale Voraussetzung für die Erforschung von Flüssigkeitseinschlüssen. Bisherige Reinigungsmethoden für Wirtsminerale sind für die FT-ICR-MS Analyse nicht geeignet, und es musste eine rigorosere Reinigungsmethode entwickelt werden. Es wurden zwei Fluorit- und zwei Quarzproben, die eine große Anzahl von Ölflüssigkeitseinschlüssen enthielten, ausgewählt, um eine verbesserte Reinigungsmethode für die Wirtsmineralien zu entwickeln. Bei dieser Methode kommen verschiedene Extraktionsverfahren wie Soxhlet- und Ultraschallextraktion mit unterschiedlichen anorganischen und organischen Lösungsmitteln zum Einsatz. Obwohl nicht immer alle Verunreinigungen vollständig von den Wirtsmineraloberflächen entfernt werden konnten, ermöglicht das Verfahren die Identifizierung externer Verunreinigungen und damit die Bewertung des Verunreinigungsgrads einzelner NSO-Verbindungsklassen. Dies erlaubt eine ausgewogene Interpretation der FT-Ergebnisse aus Flüssigkeitseinschlüssen unter Berücksichtigung des Verunreinigungsgrades insbesondere für Verbindungen, die im APPI (+) aber auch im ESI (–) Modus gemessen wurden. Darüber hinaus konnte gezeigt werden, dass die zuvor bei der FT-Untersuchung von Rohölen und Sedimentextrakten entwickelten NSO-Parameter auch in der Erforschung von Ölflüssigkeitseinschlüssen verwendet werden können. In der ersten Fallstudie wurde die Ölfüllungs- und Leckagegeschichte des Skarv-Feldes A in der Haltenbanken-Region vor der norwegischen Küste untersucht. Ölflüssigkeitseinschlüsse in Quarzen aus den Sandsteinen der jurassischen Garn- und Tilje Formation (Fm), die die ursprüngliche Ölfüllung darstellen, wurden mit den entsprechenden adsorbierten Resten von Ölen auf den Wirtsmineraloberflächen verglichen, die die aktuelle Ölfüllung des Reservoirs repräsentieren. Die umfassenden Analysen von Biomarkern, stabilen Kohlenstoffisotopen und NSO-Verbindungen zeigen, dass sowohl die Ölflüssigkeitseinschlüsse aus der Garn- und Tilje Fm als auch das adsorbierte Öl aus der Tilje Fm aus einer ähnlichen Quelle mit vergleichbarem Alter stammen, während das adsorbierte Öl aus der Garn Fm einen niedrigeren Reifegrad und Unterschiede bei den Faziesindikatoren aufweist. Die ähnlichen geochemischen Signale für die Ölflüssigkeitseinschlüsse aus der Tilje- und Garn Fm deuten darauf hin, dass die Öle aus demselben Muttergestein stammen, höchstwahrscheinlich der spätjurassischen/frühkreidezeitlichen Spekk Fm. Die Tatsache, dass das adsorbierte Öl in der Tilje Fm dem aus den entsprechenden Flüssigkeitseinschlüssen ähnelt, deutet darauf hin, dass die Tilje Fm nur einmal befüllt wurde. Im Gegensatz dazu weisen die Unterschiede zwischen dem adsorbierten Öl und dem Öl aus den Flüssigkeitseinschlüssen in der Garn Fm darauf hin, dass das Öl der ersten Reservoirbefüllung bereits mittels tertiärer Migration aus der Fm migriert ist und durch eine spätere Ölcharge aufgefüllt wurde, die vermutlich aus einem anderen, weniger reifen Muttergestein der Spekk Fm stammt. Die FT-ICR-MS NSO-Daten bestätigen die Ähnlichkeit zwischen den Flüssigkeitseinschlussölen der Garn und Tilje Fm. Aufgrund der sehr geringen Gehalte an NSO-Verbindungen in den adsorbierten Ölen war ein Vergleich zwischen den NSO-Verbindungen der Flüssigkeitseinschluss- und adsorbierten Öle mittels FT-ICR-MS für die beiden Öllagerstätten in diesem Fall nicht möglich. In der zweiten Fallstudie wurde das Fraktionierungsverhalten von Kohlenwasserstoffen und NSO-Verbindungen während der primären Ölmigration in der kalkhaltigen Hosszúhetény Marl Formation (HCMF) im Mecsek-Gebirge (Ungarn) untersucht. Hierbei repräsentieren die Ölflüssigkeitseinschlüsse die primäre Ölmigrationsphase und die Extrakte aus dem HCMF-Muttergestein das zurückgehaltene Bitumen. Diese Öl-Muttergesteinsbeziehung wurde durch die Ähnlichkeit von Biomarkerparametern und stabilen Kohlenstoff-Isotopendaten bestätigt. Der Vergleich der Ergebnisse von Ölflüssigkeitseinschlüssen und Muttergesteinsextrakten zeigt, dass die Verbindungsklassen der O1-, N1-, N1O1- und S1O1-Komponenten bevorzugt im Muttergesteinsbitumen zurückgehalten werden, während S1-Verbindungen bevorzugt aus dem Muttergestein migrieren. O2- und Kohlenwasserstoffverbindungen scheinen auf den ersten Blick keine Präferenz zu zeigen. Darüber hinaus zeigt ein tieferer Blick in die NSO-Verbindungsklassen, dass Verbindungen mit einer höheren Aromatizität bevorzugt im Muttergestein zurückgehalten werden, was insbesondere für Verbindungen mit einer hohen Anzahl von Doppelbindungsäquivalenten (DBEs) im unteren Kohlenstoffzahlbereich gilt. Dies deutet auf kürzere Alkylketten an den aromatischen Strukturen und damit auf einen weniger stark ausgeprägten Abschirmungseffekt durch die Alkylseitenketten hin. Insgesamt liefert diese Studie deutliche Hinweise darauf, dass die Fraktionierung von Kohlenwasserstoffen und NSO-Verbindungen während der primären Migration von den verschiedenen funktionellen Gruppen und deren Polaritäten sowie von der Molekülform und -größe insbesondere dem Grad der Aromatizität beeinflusst wird.

Description: Knowledge of oxygen diffusion in garnet is crucial for a correct interpretation of oxygen isotope signatures in natural samples. A series of experiments was undertaken to determine the diffusivity of oxygen in garnet, which remains poorly constrained. The first suite included high-pressure (HP), nominally dry experiments performed in piston-cylinder apparatus at: (1) T = 1050–1600 °C and P = 1.5 GPa and (2) T = 1500 °C and P = 2.5 GPa using yttrium aluminum garnet (YAG; Y3Al5O12) cubes. Second, HP H2O-saturated experiments were conducted at T = 900 °C and P = 1.0–1.5 GPa, wherein YAG crystals were packed into a YAG + Corundum powder, along with 18O-enriched H2O. Third, 1 atm experiments with YAG cubes were performed in a gas-mixing furnace at T = 1500–1600 °C under Ar flux. Finally, an experiment at T = 900 °C and P = 1.0 GPa was done using a pyrope cube embedded into pyrope powder and 18O-enriched H2O. Experiments using grossular were not successful. Profiles of 18O/(18O+16O) in the experimental charges were analyzed with three different secondary ion mass spectrometers (SIMS): sensitive high-resolution ion microprobe (SHRIMP II and SI), CAMECA IMS-1280, and NanoSIMS. Considering only the measured length of 18O diffusion profiles, similar results were obtained for YAG and pyrope annealed at 900 °C, suggesting limited effects of chemical composition on oxygen diffusivity. However, in both garnet types, several profiles deviate from the error function geometry, suggesting that the behavior of O in garnet cannot be fully described as simple concentration-independent diffusion, certainly in YAG and likely in natural pyrope as well. The experimental results are better described by invoking O diffusion via two distinct pathways with an inter-site reaction allowing O to move between these pathways. Modeling this process yields two diffusion coefficients (D values) for O, one of which is approximately two orders of magnitude higher than the other. Taken together, Arrhenius relationships are: logDm2s−1=−7.2(±1.3)+(−321(±32)kJmol−12.303RT) for the slow pathway, and logDm2s−1=−5.4(±0.7)+(−321(±20)kJmol−12.303RT) for the fast pathway. We interpret the two pathways as representing diffusion following vacancy and inter-stitial mechanisms, respectively. Regardless, our new data suggest that the slow mechanism is prevalent in garnet with natural compositions, and thus is likely to control the retentivity of oxygen isotopic signatures in natural samples. The diffusivity of oxygen is similar to Fe-Mn diffusivity in garnet at 1000–1100 °C and Ca diffusivity at 850 °C. However, the activation energy for O diffusion is larger, leading to lower diffusivities at P-T conditions characterizing crustal metamorphism. Therefore, original O isotopic signatures can be retained in garnets showing major element zoning partially re-equilibrated by diffusion, with the uncertainty caveat of extrapolating the experimental data to lower temperature conditions.

Description: This repository contains the codes produced for the article "Long-term observations reveal rise in early summer methane emissions from Siberian tundra" by Norman Rößger, Torsten Sachs, Christian Wille, Julia Boike and Lars Kutzbach. In the article, the authors report an increasing trend of methane emissions for June and July at a permafrost site in Siberia (Lena River Delta). Using the longest set of observational methane flux data in the Arctic, the authors demonstrate that the continuous warming has begun to trigger the projected enhancement of methane release in Arctic permafrost ecosystems. This software is written in MATLAB. Running the codes ([.m files](Code)) and loading the data files ([.mat files](Data)) requires the pre-installation of [MATLAB](/https://de.mathworks.com/products/matlab.html). IMPORTANT: The repository only contains dummy data. The data that is needed to run the code can be requested by Torsten Sachs and Christian Wille (contact authors). Although the scripts and the data files have been tested for newer versions of MATLAB (〉= MATLAB R2017a). The code might also run in older versions of MATLAB, but this has not been tested.

Description: The Gram-positive bacterium Nocardioides alcanivorans NGK65T was isolated from plastic-polluted soil and cultivated on medium with polyethylene as the single carbon source. Nanopore sequencing revealed the presence of candidate enzymes for the biodegradation of polyethylene. Here, we report the draft genome of this newly described member of the terrestrial plastisphere.

Description: Volcano-seismic signals such as long-period events and tremor are important indicators for volcanic activity and unrest. However, their wavefield is complex and characterization and location using traditional seismological instrumentation is often difficult. In 2019 we recorded the full seismic wavefield using a newly developed 3C rotational sensor co-located with a 3C traditional seismometer on Etna, Italy. We compare the performance of the rotational sensor, the seismometer and the Istituto Nazionale di Geofisica e Vulcanologia-Osservatorio Etneo (INGV-OE) seismic network with respect to the analysis of complex volcano-seismic signals. We create event catalogs for volcano-tectonic (VT) and long-period (LP) events combining a STA/LTA algorithm and cross-correlations. The event detection based on the rotational sensor is as reliable as the seismometer-based detection. The LP events are dominated by SH-type waves. Derived SH phase velocities range from 500 to 1,000 m/s for LP events and 300–400 m/s for volcanic tremor. SH-waves compose the tremor during weak volcanic activity and SH- and SV-waves during sustained strombolian activity. We derive back azimuths using (a) horizontal rotational components and (b) vertical rotation rate and transverse acceleration. The estimated back azimuths are consistent with the INGV-OE event location for (a) VT events with an epicentral distance larger than 3 km and some closer events, (b) LP events and tremor in the main crater area. Measuring the full wavefield we can reliably analyze the back azimuths, phase velocities and wavefield composition for VT, LP events and tremor in regions that are difficult to access such as volcanoes.

Description: In site-specific site-response assessments, observation-based site-specific approaches requiring a target–reference recording pair or a regional recording network cannot be implemented at many sites of interest. Thus, various estimation techniques have to be used. How effective are these techniques in predicting site-specific site responses (average over many earthquakes)? To address this question, we conduct a systematic comparison using a large data set which consists of detailed site metadata and Fourier outcrop linear site responses based on observations at 1725 K-NET and KiK-net sites. We first develop machine learning (i.e. random forest (RF)) amplification models on a training data set (1580 sites). Then we test and compare their predictive powers at 145 independent testing sites with that of the one-dimensional (1D) ground response analysis (GRA). The standard deviation of residuals between observations and predictions, that is, between-site (site-to-site or inter-site) variability, is used as the benchmark. Results show that the machine learning model using a few predictor variables, surface roughness, peak frequency fP, HV, VS30, and depth Z2.5 achieves better performance than the physics-based modeling (GRA) using detailed 1D velocity profiles. This implies that machine learning can be more effective in using existing site information than 1D GRA which is inflicted by a high level of parametric and modeling uncertainties. This finding warrants the further exploration of machine learning in site effect characterization, especially on model transferability across different regions.

Description: The time-averaged shear-wave velocity in the upper 30 m of the ground, VS30, is a key soil descriptor for estimating site response despite its recognized limitations. It is employed in both, site-specific probabilistic hazard assessments (PSHAs) and regional seismic codes. This work presents a model for estimating VS30 in the Iberian Peninsula as a function of three proxies: topographic slope, geological age and lithology at each site. Tasks accomplished include: 1) gathering existing Vs profiles and calculating their VS30; 2) defining an adequate set of representative age and lithological groups; 3) classifying the available VS profiles according to these groups; and 4) carrying out a regression analysis between VS30, slopes, age and lithological groups. Based on the regression analysis and the dependency on the slope, some of the initially proposed groups were amalgamated, before proposing the final model. This model considers topographic slope values extracted from a digital elevation model (DEM) with 200 m horizontal resolution, plus six geological age groups and four lithological groups. It provides an estimate of the mean and standard deviation of (and hence VS30), which can be used for sites without direct estimates of velocity profiles (and VS30) in the Iberian Peninsula.

Description: It has been recently demonstrated that Machine Learning (ML) can predict laboratory earthquakes. Here we propose a prediction framework that allows forecasting future surface velocity fields from past ones for analog experiments of megathrust seismic cycles. Using data from two types of experiments, we explore the prediction performances of multiple Deep Learning (DL) and ML algorithms. In such a self-supervised regression, no feature extraction is required and the entire seismic cycle is forecasted. The onset, magnitude, and propagation of analog earthquakes can thus be predicted at different prediction horizons. From all architectures tested in this study, convolutional recurrent neural networks (CNN-LSTM and CONVLSTM) provide the best predictions although their performances depend on experiment characteristics and hyperparameters tuning. Analog earthquakes can be successfully anticipated up to a horizon of the order of their duration. This laboratory-based study may open new avenues for transfer learning applications with data from natural subduction zones.

Description: The interactive web page contains supplementary information to Acoustic signals of a meteoroid recorded on a large-N seismic network and fibre optic cables. It aggregates the probabilistic trajectory inversion results for the observed meteor explosion above south Iceland on July 2, 2022. These inversion results of a hypersonic moving source model (MSM) are based on travel time picks of the first arrival (A1) and the last arrival (LA), both, in homogeneous and layered atmospheric model. Additionally we present the inversion results of a simple point source model (PSM) based on the arrival times of A1 and LA.

Description: In Haeger et al. (2022), we created a three dimensional model of the temperature distribution and the geothermal heat flow of the Antarctic lithosphere as well as a new model of the lithosphere-asthenosphere boundary (LAB). The models were obtained in a three-step approach: First, we calculate the initial temperature distribution in the upper mantle by iteratively combining seismic tomography (An et al., 2015; Schaeffer amp; Lebedev, 2013) and gravity data (Förste et al., 2014; Scheinert et al., 2016) considering composition and density variations self-consistently (Haeger et al., 2019). Second, we define the lithosphere-asthenosphere boundary in a thermal sense based on the resulting geotherm by assuming it corresponds to the 1300°C isotherm. Third, we solve the steady-state heat equation to obtain the temperature distribution and the geothermal heat flow in the lithosphere. One crucial yet still largely unknown factor in the model is the parametrization of the crust. In order to overcome this, we calculated thermal models for a range of crustal properties that are described in detail in Haeger et al. (2022) and the related supplementary material. Here, we only share the conductive temperature and the geothermal heat flow model for the preferred model (n° 29 in the supplementary) in binary netCDF files. Additionally, we present the depth to LAB and surface and mantle heat flow maps, the latter represents the heat flow at the depth of the Moho discontinuity (Haeger et al., 2019) as .txt ascii tables. As a measure of uncertainty of the preferred surface heat flow model, the standard deviation of all calculated models is additionally given. The models are presented in polar stereographic projections with true scale at 71° South (Snyder, 1987) and span ±3700 km with a 10 km spacing in x- and y-direction, respectively. For the netCDF files, the depth ranges from the bedrock surface (BedMachine, Morlighem et al., 2020) which is defined as the 0 level to the LAB in a 1 km spacing. The depths to the Moho and the LAB are given relative to sea level.

Description: The study introduces an efficient methodology to perform the transformations between station coordinate and velocity solutions where either minimum or redundant datum constraints have been imposed employing the estimated state vector and the covariance matrix thereof. The analytical methodology presented herein facilitates the datum alignment of large-network solutions, especially for the GNSS technique. The computational complexity reduction is achieved by avoiding the expensive normal equation system reconstruction and the subsequent inversion thereof, which is the current norm, in favor of an elegant approach involving the inversion of an up to 14-order matrix. All information parsed in our algorithm is readily available in the widely used space geodetic solution files following the Solution Independent Exchange (SINEX) format. Our transformation approach is evaluated in two globally distributed GNSS-derived solutions and one terrestrial reference frame with a spatial concentration in South America. The results prove the equivalence of the current and proposed algorithm and that our approach is at least an order of magnitude faster. In addition, we test the Fast Constraints Transformation (FCT) through simulated networks, with a size of up to 5000 stations. The FCT presented here accelerates the transformation by almost 140 times compared to the commonly used strategy.

Description: Intervals of pulsations of diminishing periods (IPDPs) are a subtype of electromagnetic ion cyclotron (EMIC) waves that can be triggered by substorm onset. Pi1B waves are ultralow frequency (ULF) broadband bursts that are well correlated with substorm onset. IPDPs are associated with increased fluxes of 40–60 keV substorm-injected protons which undergo gradient-curvature drifting and interact with the cold plasmasphere population. While particle trajectories and the generation of IPDPs have been modeled in the past, those models neglect the role that drift shell splitting plays in the process. This research investigates the different pathways that Pi1B and IPDPs take from their shared origin in substorm onset to their distinct observations on the ground, including the effects of drift shell splitting en route. This paper presents two case studies using data from an array of four ground-based Antarctic magnetometers that cover the evening sector, as well as in situ magnetometer data, proton fluxes, and proton pitch angles from the Van Allen Probes spacecraft. These observations identify a separation in geomagnetic latitude between Pi1Bs and IPDPs, and pinpoint a separation in magnetic local time (MLT). From these observations we model the drift shell splitting which injected particles undergo post-onset. This study shows that simulations that incorporate drift shell splitting across a full injection front are dominated by injection boundary effects, and that the inclusion of drift shell splitting introduces a slight horizontal component to the time axis of the time–frequency dependence of the IPDPs.

Description: Systematic changes in whole-rock chemistry, mineralogy, mineral textures, and mineral chemistry are seen along a ca. 95-km traverse of late Archean granitoid orthogneisses in the Shevaroy Block, Eastern Dharwar Craton, southern India. The traverse passes from amphibolite-grade gneisses in the north to granulite-grade rocks (charnockite) in the south. Changes include whole-rock depletion of Rb, Cs, Th, and U in the granulite grade rocks as relative to the amphibolite grade gneisses, and oxidation trends regionally from highly oxidised granulite-facies rocks near the magnetite–haematite buffer to relatively reduced amphibolite-facies rocks below the fayalite-magnetite-quartz. Rare earth elements show limited mobility and are hosted a variety of minerals whose presence is dependent on the metamorphic grade ranging from titanite and allanite in the amphibolite-facies rocks to monazite in the vicinity of the orthopyroxene-in isograd to apatite in the granulite-grade charnockite. Cathodoluminescence and back-scattered electron sub-grain imaging and sensitive high-resolution ion microprobe analysis of zircon from 29 samples of dioritic, tonalitic, and granitic orthogneiss from the traverse reveals magmatic zircon cores that record the emplacement of the granitoid protoliths mostly about 2580 to 2550 Ma, along with a few older mid to late Archean tonalites. Protolith zircon was modified during metamorphism by overgrowth and/or replacement. Relative to igneous cores, U-enriched metamorphic zircon, dominant in the amphibolite-grade gneisses, formed at ca. 2530 Ma, predating retrograde titanite growth at ca. 2500 Ma. Uranium-depleted mantles grew on zircon between 2530 and 2500 Ma in granulite-grade samples south of the orthopyroxene-in isograd. In some of these samples, the U-depleted metamorphic zircon is preceded by mantles of U-undepleted zircon, indicating a progression of metamorphic zircon growth with increasingly depleted compositions between 2530 and 2500 Ma. With increasing metamorphic grade (from amphibolite to granulite) and oxidation state, allanite and monazite disappear from the assemblage and zircon became depleted in U and Th. Whole-rock U-Th compositions became decoupled from relict magmatic zircon compositions, reflecting the development of U-depleted metamorphic zircon and indicating that whole-rock chemical differences along the traverse were produced during metamorphism, rather than just reflecting differences in dioritic vs granitic protoliths. Although in situ anatexis and melt extraction may have played a role, whole-rock and zircon depletion of trace elements can be explained by the action of externally derived, oxidising, low-H2 O activity hypersaline fluids migrating up through the mid to lower crust. Fluids and element migration during metamorphism may be the end result of subduction related processes that cumulated in the collision and concatenation of island arcs and continental blocks. These tectonic processes assembled the Dharwar Craton at the end of the Archean.

Description: The understanding of the coupled thermo-hydro-mechanical behaviour of fault zones in naturally fractured reservoirs is essential both for fundamental and applied sciences and in particular for the safety assessment of radioactive waste disposal facilities. In this framework, an international research program callled CHENILLE was built to address key questions related to the impact of high temperatures (up to 150°C) on shear zones as well as fault reactivation processes in shale formations. The project includes a thermally controlled in situ fluid injection experiment on a strike-slip fault zone outcropping atIRSN’s Tournemire Underground Research Laboratory (URL) and a series of laboratory experiments to understand the chemical and structural evolution occurring within the fault zones during the thermal and hydraulic loading. The in situ experiment includes a heating system installed around an injection borehole will enable a precise and controlled incremental increase of the thermal load. The injection borehole will be equiped with a Step-Rate Injection Method for Fracture In-Situ Properties (SIMFIP) probe, in order to perform step pressure tests. The probe will not only measure the flow and pressure rate inside the injection borehole but also allow to monitor the borehole’s 3D deformation during the hydraulic and thermal loading steps. In addition, an array of seismicifferent sensors will be implemented around the injection area to measure the seismic and aseismic deformation induced either by thermal or by hydraulic loading. The seismic monitoring system is composed of Acoustic Emission (sensitive between 1kHz and 60kHz) enabling monitoring fracturing processes of sub-decimeter size. Furthermore, a fibre optic network will be installed in the heating boreholes to measure spatially temperature variationsvia Distributed Temperature Sensing technology in the investigation area. Active seismic surveys, using different source types, are scheduled before and after the experiment to determine the structural network but also to detect the appearance of new structures triggered from the hydro-thermal pressurization of the fault by tomography and reflection seismic methods. The overall goal of our work is to present the interaction between the different geophysical methods that we are using as well as some preliminary results. A first part is dedicated to the description of the fault zone through field and core samples observations as well as borehole to borehole correlation, whereas the second is dedicated to preliminary results on the thermal diffusion expected in the fault.

Description: As environmental seismology has been rapidly growing and developing over the past years, one of the fields that is benefitting from this seismic revolution is the study of geomorphic processes. Seismic methods provide a unique and powerful tool for the observation of geomorphic activity, allowing us to address questions that were not possible (or extremely difficult) to tackle with other techniques. From the perspective of geomorphologists, we give an overview of three general areas in which seismic techniques have been or have the potential to enable significant advances in our understanding of geomorphic processes: (1) the occurrence, timing, and triggering of geomorphic events, (2) the dynamics of geomorphic processes, (3) fluvial bedload transport, and we look towards future developments in integrative geomorphic system monitoring. In order to keep the seismic advances coming, integration between geomorphologists and seismologists is key, as the community continues to identify key geomorphic questions that seismology can help answer and in parallel develops the theory, analytical techniques, and measurement strategies needed for application to new geomorphic questions.

Description: The European Plate Observing System EPOS is the single coordinated framework for solid Earth science data, products and services on a European level. As one of the science domain structures within EPOS, EPOS Seismology brings together the three large European infrastructures in seismology: ORFEUS for seismic waveform data & related products, EMSC for parametric earthquake information, and EFEHR for seismic hazard and risk information. Across these three pillars, EPOS Seismology provides services to store, discover and access seismological data and products from raw waveforms to elaborated hazard and risk assessment. ORFEUS, EMSC and EFEHR are community initiatives / infrastructures that each have their own history, structure, membership, governance and established mode of work (including data sharing and distribution practices), developed in parts over decades. While many institutions and individuals are engaged in more than one of these initiatives, overall the active membership is quite distinct. Also, each of the initiatives has different connections to and interactions with other international organisations. Common to all is the adoption and promotion of recognized international standards for data, products and services originating from wider community organisations (e.g. FDSN, IASPEI, GEM), and the active participation in developing those further or creating new ones together with the community. In this presentation we will briefly review the history and development of the three initiatives and discuss how we set up EPOS Seismology as a joint coordination framework within EPOS. We will highlight issues encountered on the way and those that we are still trying to solve in our attempt to create and operate a coordinated research infrastructure that appropriately serves the needs of today’s scientific community. Among those issues is also the ‘timeliness’ of data and products: while a number of services offer almost-real-time access to newly available information at least in theory, this comes with various downstream implications that are currently actively discussed. We also cover the envisaged role of EPOS Seismology in supporting international multi-disciplinary activities that require and benefit from harmonized, open, and interoperable data, products, services and facilities from the waveform, catalogue and hazard / risk domains of seismology.

Description: Rainfall-triggered landslides in urban areas cause fatalities and damage globally, but landslide early warning systems operating in individual cities rely on different data sources and methods, making a comparison of thresholds challenging. In this study, we estimate the distribution of intensity-duration (I-D) and event-duration (E-D) rainfall thresholds for landslide occurrence in cities worldwide. We develop a global compilation of urban landslides and extract the coincident event rainfall from two global precipitation datasets: the hourly resolution, gauge-based Global Sub-Daily Rainfall Dataset (GSDR; Lewis et al., 2019) and the half-hourly resolution, gridded, satellite-based Global Precipitation Measurement mission (GPM-IMERG; Huffman et al., 2014). We then use Bayesian multi-level quantile regression to determine 5% I-D and E-D thresholds for each city within a single model. This approach offers an objective way to determine rainfall thresholds and their uncertainty while explicitly modeling variation between cities. Preliminary results show that I-D thresholds in urban areas are much lower than previously reported global thresholds (Guzzetti et al., 2008), and that posterior parameter estimates for the rainfall threshold slope are indistinguishable from zero in most cases. Rainfall thresholds in cities with widely varying climates, topography, and population densities are often indistinguishable from each other. At short durations (hours to days), landslide triggering rainfall has often been moderate, with high annual exceedance probabilities. At longer durations (days to weeks), landslide triggering rainfall has frequently been among the highest recorded events. We hypothesize that the processes controlling landsliding in cities are fundamentally different from those in natural settings. We surmise that anthropogenic controls such surface sealing, slope engineering, and artificial drainage play a dominant role for slope stability in urban areas, resulting in a harmonizing effect on rainfall thresholds in many cities throughout the world.

Description: For around 700 hundred years, the greater Ruhr region has been the heart of the coal mining industry in Germany. In 2018, the last coal mine ceased operation in the country, and the process of abandonment and repurposing of the vast amounts of unused subsurface infrastructure has begun. The operations of mine flooding as well as the recent geothermal exploration campaigns, aiming to utilize old mine infrastructure as well as permeable Massenkalk formations found below mining depths, pose serious questions regarding safety and potential seismic risks in the densely populated greater Ruhr region. To alleviate these concerns, we assess the probability of reactivation of major fault in the region. This study benefits from the astonishing amount of 429 stress magnitude and 38 stress orientation data records derived from hydrofracturing tests and borehole logs carried out in six coal mines and two coal bed methane boreholes between 1986 and 1995. Due to the change in subsurface data regulations, this data has been just recently made available to the public. Our study summarizes the results of this extensive in situ stress test campaign, assigns quality to each data record using the established quality ranking schemes of the World Stress Map project for both stress orientations and magnitudes, and, in combination with already published material, provides the first comprehensive stress database of the region. This unique data set, together with geometries of major faults revealed from coal mining activities and already published results from laboratory studies, serves as a base for the probabilistic assessment of fault reactivation potential, incorporating uncertainty of each Mohr-Coulomb parameter (i.e., stress tensor, pore pressure, frictional properties, and fault geometry). The probabilistic assessment of fault reactivation potential, as presented in this study, aims to de-risk future subsurface operations facilitating the green transition of the greater Ruhr region.

Description: Analyzing large seismic datasets and extracting information is becoming more challenging with the continuously growing amount of seismic records. Machine learning (ML) techniques have been utilized as powerful statistical tools for efficient seismic processing. Among other applications, ML algorithms allow the clustering of seismic data in order to reveal different patterns in the data or to identify types of signals for further analysis. The dominant uses of clustering algorithms in seismology have been in the realm of transient earthquake signal analysis. Clustering long lasting signals like volcanic tremors is however another appealing problem that could benefit from ML techniques albeit being slightly more complicated due to their high variability in signal properties such as time duration and time-frequency content. Here we use deep clustering (combination of deep learning and clustering) in order to cluster lava fountaining episodes which are recorded as tremor episodes in the seismic waveform between 2 May and 14 June 2021 during the Fagradalsfjall eruption in Iceland. Using an autoencoder, our model simultaneously learns feature representations and assigns clusters to them. The tremor episodes show systematic changes during the eruptive periods of Fagradalsfjall eruption consisting of distinct patterns with changing tremor duration, repose time and corresponding amplitude. The relation between tremor duration and repose time and their regular changes can indicate special volcanic activity stages containing starting, evolving, and stabilizing sequences. Unsupervised deep learning techniques help to automatically identify patterns in the data, find similar/dissimilar pulses, and lead to a better understanding of the subsurface processes and eruptive activities. The primary investigation on tremor pulses clustering is promising while further analysis is ongoing.

Description: Blooms of microalgae on glaciers and ice sheets are amplifying surface ice melting rates, which are already affected by climate change. Most studies on glacial microorganisms (including snow and glacier ice algae) have so far focused on the spring and summer melt season, leading to a temporal bias, and a knowledge gap in our understanding of the variations in microbial diversity, productivity, and physiology on glacier surfaces year-round. Here, we investigated the microbial communities from Icelandic glacier surface snow and bare ice habitats, with sampling spanning two consecutive years and carried out in both winter and two summer seasons. We evaluated the seasonal differences in microbial community composition using Illumina sequencing of the 16S rRNA, 18S rRNA, and ITS marker genes and correlating them with geochemical signals in the snow and ice. During summer, Chloromonas, Chlainomonas, Raphidonema, and Hydrurus dominated surface snow algal communities, while Ancylonema and Mesotaenium dominated the surface bare ice habitats. In winter, algae could not be detected, and the community composition was dominated by bacteria and fungi. The dominant bacterial taxa found in both winter and summer samples were Bacteriodetes, Actinobacteria, Alphaproteobacteria, and Gammaproteobacteria. The winter bacterial communities showed high similarities to airborne and fresh snow bacteria reported in other studies. This points toward the importance of dry and wet deposition as a wintertime source of microorganisms to the glacier surface. Winter samples were also richer in nutrients than summer samples, except for dissolved organic carbon—which was highest in summer snow and ice samples with blooming microalgae, suggesting that nutrients are accumulated during winter but primarily used by the microbial communities in the summer. Overall, our study shows that glacial snow and ice microbial communities are highly variable on a seasonal basis.

Description: This dataset provides annually resolved microfacies data from ICDP core 5017-1-A, retrieved from the deep northern Dead Sea basin in 2010/11, for the last glacial-interglacial transition (ca. 14-13 ka BP). Sediments of the Lisan Formation were investigated between ~94.7 and 91.8 m sediment depth below lake floor (lithozone C2) by continuous thin section microscopy. Thin sections were prepared following the standard procedure by Brauer and Casanova (2001) that was adjusted for salty sediments. Thin section analyses were performed on overlapping large-scale thin sections using a Zeiss Axiolab pol microscope at magnifications of 50-400x. Microfacies analyses included varve counting and measurements of varve and sublayer thickness. The amount of varves in erosional gaps was interpolated and the position of mass flow deposits (MFD) is marked.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: Organic carbon (OC) stored in Arctic permafrost represents one of Earth’s largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits are still poorly quantified. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ~52 ka. We show that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt%).We found that the OM quality, which we define as the intrinsic potential to further transformation, decomposition, and mineralization, is also high as inferred by the lipid biomarker inventory. The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal kyr BP) and is overlaid by Last Glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso and anteiso-branched FAs relative to long chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits, suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C / N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease of HPFA values downwards along the profile probably indicates a relatively stronger OM decomposition in the oldest (MIS 3) deposits of the cliff.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: These datasets describe sediment samples taken from the Batagay megaslump, located in Yana Uplands in northeastern Siberia. Most sediment samples were taken from the slump headwall (B19-P1) by rapelling down on a rope from the slump surface and taking samples with a hole saw (diameter 55 mm, 40 mm deep) mounted on a handheld power drill. A second profile (B19-02) of the lowest part of the slump headwall was sampled (~100 m south) using a hammer and axe from the slump floor. Two permafrost sediment blocks (B19-03 and B19-04) at the slump bottom that had fallen from the headwall were sampled using a chainsaw. Finally, a baidzherakh (thermokarst mound; B19-05) in the north of the slump was sampled using a hammer and axe. The samples cover 5 stratigraphical units: 1. lower ice complex, 2. lower sand unit, 3. woody layer, 4. upper ice complex, 5. Holocene cover.