ALBERT

Description: The Institute of Seismology, University of Helsinki (ISUH) was founded in 1961 as a response to the growing public concern for environmental hazards caused by nuclear weapon testing. Since then ISUH has been responsible for seismic monitoring in Finland. The current mandate covers government regulator duties in seismic hazard mitigation and nuclear test ban treaty verification, observatory activities and operation of the Finnish National Seismic Network (FNSN) as well as research and teaching of seismology at the University of Helsinki. The first seismograph station of Finland was installed at the premises of the Department of Physics, University of Helsinki in 1924. However, the mechanical Mainka seismographs had low magnification and thus the recordings were of little practical value for the study of local seismicity. The first short-period seismographs were set up between 1956 and 1963. The next significant upgrade of FNSN occurred during the late 1970’s when digital tripartite arrays in southern and central Finland became fully operational, allowing for systematic use of instrumental detection, location and magnitude determination methods. By the end of the 1990’s, the entire network was operating using digital telemetric or dial-up methods. The FNSN has expanded significantly during the 21st Century. It comprises now 36 permanent stations. Most of the stations have Streckeisen STS-2, Nanometrics Trillium (Compact/P/PA/QA) or Guralp CMG-3T broad band sensors. Some Teledyne-Geotech S13/GS13 short period sensors are also in use. Data acquisition systems are a combination of Earth Data PS6-24 digitizers and PC with Seiscomp/Seedlink software or Nanometrics Centaurs. The stations are connected to the ISUH with Seedlink via Internet and provide continuous waveform data at 40 Hz (array) or 100-250 Hz sampling frequency. Further information about instrumentation can be found at the Institute’s web site (www.seismo.helsinki.fi). Waveform data is available from the GEOFON data centre.

Description: Raw, SEGY and other supplementary data are presented from the seismic refraction / wide-angle reflection profile, TTZ-South, in Poland and Ukraine. The purpose of this 550 km long seismic profile was to reveal the lithospheric structure along the Teisseyre-Tornquist Zone (TTZ), a major geophysical boundary in Europe.

Description: Due to the major role of greenhouse gas emissions in global climate change, the development of non-fossil energy technologies is essential. Deep geothermal energy represents such an alternative, which offers promising properties such as a high base load capability and a large untapped potential. The present work addresses barite precipitation within geothermal systems and the associated reduction in rock permeability, which is a major obstacle to maintaining high efficiency. In this context, hydro-geochemical models are essential to quantify and predict the effects of precipitation on the efficiency of a system. The objective of the present work is to quantify the induced injectivity loss using numerical and analytical reactive transport simulations. For the calculations, the fractured-porous reservoirs of the German geothermal regions North German Basin (NGB) and Upper Rhine Graben (URG) are considered. Similar depth-dependent precipitation potentials could be determined for both investigated regions (2.8-20.2 g/m3 fluid). However, the reservoir simulations indicate that the injectivity loss due to barite deposition in the NGB is significant (1.8%-6.4% per year) and the longevity of the system is affected as a result; this is especially true for deeper reservoirs (3000 m). In contrast, simulations of URG sites indicate a minor role of barite (〈 0.1%-1.2% injectivity loss per year). The key differences between the investigated regions are reservoir thicknesses and the presence of fractures in the rock, as well as the ionic strength of the fluids. The URG generally has fractured-porous reservoirs with much higher thicknesses, resulting in a greater distribution of precipitates in the subsurface. Furthermore, ionic strengths are higher in the NGB, which accelerates barite precipitation, causing it to occur more concentrated around the wellbore. The more concentrated the precipitates occur around the wellbore, the higher the injectivity loss. In this work, a workflow was developed within which numerical and analytical models can be used to estimate and quantify the risk of barite precipitation within the reservoir of geothermal systems. A key element is a newly developed analytical scaling score that provides a reliable estimate of induced injectivity loss. The key advantage of the presented approach compared to fully coupled reservoir simulations is its simplicity, which makes it more accessible to plant operators and decision makers. Thus, in particular, the scaling score can find wide application within geothermal energy, e.g., in the search for potential plant sites and the estimation of long-term efficiency.

Description: Aufgrund der tragenden Rolle der Treibhausgasemissionen für den globalen Klimawandel ist die Entwicklung von nicht-fossilen Energietechnologien essenziell. Die Tiefengeothermie stellt eine solche Alternative dar, welche vielversprechende Eigenschaften wie eine hohe Grundlastfähigkeit und ein großes ungenutztes Potenzial bietet. Die vorliegende Arbeit befasst sich mit Barytausfällungen inner- halb geothermaler Systeme und der damit einhergehenden Verringerung der Gesteinsdurchlässigkeit, welche ein Haupthindernis für die Aufrechterhaltung einer hohen Effizienz darstellen. Dabei sind hydro-geochemische Modelle unerlässlich, um die Auswirkungen von Ausfällungen auf die Effizienz eines Systems zu quantifizieren und vorherzusagen. Ziel der vorliegenden Arbeit ist es, mittels numerischer und analytischer reaktiver Transportsimulationen, den induzierten Injektivitätsverlust zu quantifizieren. Für die Berechnungen werden die klüftig-porösen Reservoire der deutschen Geothermieregionen Norddeutsches Becken (NDB) und Oberrheingraben (ORG) betrachtet. Für beide untersuchte Regionen konnte ein ähnliches, tiefenabhängiges Fällungspotenzial bestimmt werden (2,8–20,2 g/m3 Fluid). Die Reservoirsimulationen zeigen jedoch, dass der Injektivitätsverlust aufgrund von Barytablagerungen im NDB erheblich ist (1,8%–6,4% pro Jahr) und die Langlebigkeit der Anlage dadurch beeinträchtigt wird, dies gilt insbesondere für tiefere Reservoire (3000 m). Im Gegensatz dazu deuten die Simulationen der ORG-Standorte auf eine untergeordnete Rolle von Baryt hin (〈 0,1%–1,2% Injektivitätsverlust pro Jahr). Die entscheidenden Unterschiede zwischen den untersuchten Regionen sind die Reservoirmächtigkeiten und das Vorhandensein von Rissen im Gestein sowie die Ionenstärke der Fluide. Der ORG weist in der Regel klüftig-poröse Reservoire mit deutlich höheren Mächtigkeiten auf, was zu einer größeren Verteilung der Präzipitate im Untergrund führt. Weiterhin sind die Ionenstärken im NDB höher, was die Barytausfällung beschleunigt und diese dadurch konzentrierter um das Bohrloch herum entstehen lässt. Je konzentrierter die Präzipitate um die Bohrung herum auftreten, desto höher ist der Injektivitätsverlust. In dieser Arbeit wurde ein Workflow erarbeitet, innerhalb dessen mittels numerischer und analytischer Modelle das Risiko von Barytausfällungen innerhalb des Reservoirs geothermischer Systeme abgeschätzt und quantifiziert werden kann. Ein zentrales Element ist ein neu entwickelter, analytischer Scaling-Score, der eine zuverlässige Schätzung des induzierten Injektivitätsverlustes ermöglicht. Der entscheidende Vorteil des präsentierten Ansatzes im Vergleich zu voll-gekoppelten Reservoirsimulationen liegt in ihrer Einfachheit, die sie für Anlagenbetreiber und Entscheidungsträger zugänglicher macht. Somit kann insbesondere der Scaling-Score eine breite Anwendung innerhalb der Geothermie finden, z.B. bei der Suche nach potenziellen Anlagenstandorten und der Abschätzung der langfristigen Effizienz.

Description: The current western margin of the South American continent is an active subduction orogeny, which is famous for the ’Andean-type’ subduction. The Andes orogeny extends more than 6000 km along the margin. The Central Andes is governed by plateau-style deformation and the subduction of the Nazca plate below Chile and western Argentina, which has caused drastic crustal shortening and thickening, magmatism and periodical back-arc lithosphere and lower crust delamination. The deformation is also influenced by the periodical dip angle variations of the Nazca plate. However, the interaction zone between the overriding plate and the subducting Nazca slab is still enigmatic. In my dissertation, I use earthquake multi-scale full waveform inversion (FWI) to image the crust and upper mantle structure providing new robust images to resolve the interactions between the slab and the Central Andean plateau. First, I performed FWI using 117 earthquakes to investigate the seismic structure for the northern Central Andes which cover the normal-dip subduction zone from southern Peru to central Chile, proceeding from long period data (40–80 s) over several steps down to 12–60 s. In this study, the subducting Nazca slab is clearly imaged in the upper mantle, with dip-angle variations from the north to the south. Bands of low velocities in the crust and mantle wedge indicate intense crustal partial melting and hydration of the mantle wedge beneath the frontal volcanic arc, respectively. They are also linked to the vigorous dehydration from the subducting Nazca plate and intermediate-depth seismicity within the slab. These low-velocity bands are interrupted at 19.8 –21 S, both in the crust and uppermost mantle with an absence of active volcanoes, hinting at the lower extent of crustal partial melting and hydration of the mantle wedge, associated with the weak dehydration from the Nazca plate. The variation of lithospheric high-velocity anomalies below the backarc from north to south allows insight into the evolutionary foundering stages of the Central Andes. An extended high-velocity layer at lithospheric depths beneath the southern Altiplano suggests underthrusting of the leading edge of the Brazilian Shield following the removal of the autochthonous lithosphere. In contrast, a steeply westward dipping high-velocity block and low-velocity lithospheric uppermost mantle beneath the southern Puna plateau hints at the ongoing lithospheric delamination. Second, I took advantage of 134 events to perform FWI and started from even longer period data 60- 120 s to 12-100 s. In this study, a new seismic velocity model for the southern Central Andes is derived, covering the Pampean flat and adjacent Payenia steep subduction segments. Strong focused crustal low-velocity anomalies indicate partial melts in the Payenia segment along the volcanic arc, whereas weaker low-velocity anomalies covering a wide zone in Pampean possibly indicate remnant melts in the past. Thinning and tearing of the flat Nazca slab below the Pampean is inferred by gaps in the high-velocity slab along the inland projection of the Juan-Fernandez-Ridge. A high-velocity anomaly in the upper mantle below the flat slab is interpreted as a relic Nazca slab segment, which indicates an earlier slab break-off during the flattening process, triggered by the buoyancy of the Juan-Fernandez-Ridge. In Payenia, large-scale low-velocity anomalies atop and below the re-steepened Nazca slab are associated with the re-opening of the mantle wedge and sub-slab asthenospheric flow, respectively.

Description: The accurate knowledge of the Earth’s orientation and rotation in space is essential for a broad variety of scientific and societal applications. Among others, these include global positioning, near-Earth and deep-space navigation, the realisation of precise reference and time systems as well as studies of geodynamics and global change phenomena. In this paper, we present a refined strategy for processing and combining Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Navigation Satellite Systems (GNSS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) observations at the normal equation level and formulate recommendations for a consistent processing of the space-geodetic input data. Based on the developed strategy, we determine final and rapid Earth rotation parameter (ERP) solutions with low latency that also serve as the basis for a subsequent prediction of ERPs involving effective angular momentum data. Realising final ERPs on an accuracy level comparable to the final ERP benchmark solutions IERS 14C04 and JPL COMB2018, our strategy allows to enhance the consistency between final, rapid and predicted ERPs in terms of RMS differences by up to 50% compared to existing solutions. The findings of the study thus support the ambitious goals of the Global Geodetic Observing System (GGOS) in providing highly accurate and consistent time series of geodetic parameters for science and applications.

Description: This field campaign aimed at densifying the station coverage on the Armutlu Peninsula in the eastern Sea of Marmara. The Armutlu peninsula is directly crossed by the Armutlu fault, located roughly ~50 km away from the Istanbul metropolitan region. The main objective of this experiment is to characterize the seismic and aseismic deformation of this region. Waveform data are available from the GEOFON data centre, under network code 9P.

Description: This dataset contains subaquatic passive seismic recordings taken in September 2021 at 88 locations off Tuktoyaktuk Island as well as in a small lake (“Lake 3”) between the villages of Tuktoyaktuk and Inuvik, Northwest Territories, Canada. The measurements were part of the “Mackenzie Delta Permafrost Field Campaign” (mCan2021) within the “Modular Observation solutions for Earth Systems” (MOSES) program. Data is from a seismic intermediate-bandwidth seismic sensor lowered for few minutes to the bottom of the sea and lake, respectively, and from underwater short-period sensors deployed for a few days. The aim of the study was to determine the depth of the subaquatic permafrost (local lake and oceanic locations). Raw data is provided in proprietary “Cube” format and standard mseed format.

Description: This data publication contains a seismic survey which was acquired in the Mont Terri Underground Rock Laboratory (URL) in January 2019. The aim of the SI-A experiment (Seismic Imaging Ahead of and around underground infrastructure) is to provide a seismic characterization at the meso scale and to investigate the feasibility of tomographic and reflection imaging in argillaceous environments. The survey covered the different facies types of Opalinus Clay: shaly facies, carbonate -rich sandy facies and sandy facies (Bossart et al. 2017). Three different seismic sources (impact, vibro, ELVIS) were used to acquire the seismic data. The impact and magnetostrictive vibro sources were particularly designed for seismic exploration in the underground (Giese et al. 2005, Richter et al. 2018). The ELVIS source was mainly designed for near-surface investigations on roads or in open terrain (Krawczyk et al. 2012). All data were recorded on 32 3-component geophones (GS-14-L3, 28 Hz) which were deployed in 2 m deep boreholes, fixed at the tip of rock anchors. The data publication covers raw and preprocessed data stored in SEG-Y format.

Description: BACKGROUND AND OBJECTIVES: Soil or rock types in a region are often interpreted qualitatively by visually comparing various geophysical properties such as seismic wave velocity and vulnerability, as well as gravity data. Better insight and less human-dependent interpretation of soil types can be obtained from a joint analysis of separated and independent geophysical parameters. This paper discusses the application of a neural network approach to derive rock properties and seismic vulnerability from horizontal-to-vertical seismic ratio and seismic wave velocity data recorded in Majalengka-West Java, Indonesia.METHODS: Seismic microtremors were recorded at 54 locations and additionally multichannel analyses of surface wave experiments were performed at 18 locations because the multichannel analyses of surface wave experiment needs more effort and space. From the two methods, the values of the average shear wave velocity for the upper 30 meters, peak amplitudes and the dominant frequency between the measurement points were obtained from the interpolation of those geophysical data. Neural network was then applied to adaptively cluster and map the geophysical parameters. Four learning model clusters were developed from the three input seismic parameters: shear wave velocity, peak amplitude, and dominant frequency. FINDINGS: Generally, the values of the horizontal to vertical spectral ratios in the west of the study area were low (less than 5) compared with those in the southeastern part. The dominant frequency values in the west were mostly low at around 0.1–3 Hertz, associated with thick sedimentary layer. The pattern of the shear wave velocity map correlates with that of the horizontal to vertical spectral ratio map as the amplification is related to the soil or rock rigidity represented by the shear wave velocity. The combination of the geophysical data showed new features which is not found on the geological map such as in the eastern part of the study area. CONCLUSION: The application of the neural network based clustering analysis to the geophysical data revealed four rock types which are difficult to observe visually. The four clusters classified based on the variation of the geophysical parameters show a good correlation to rock types obtained from previous geological surveys. The clustering classified safe and vulnerable regions although detailed investigation is still required for confirmation before further development. This study demonstrates that low-cost geophysical experiments combined with neural network-based clustering can provide additional information which is important for seismic hazard mitigation in densely populated areas.

Description: The Walvis Ridge (WR) is the most prominent hotspot track related to the opening in the South Atlantic Ocean. Several hypotheses have been developed to explain its origin and evolution. The presence of a massive magmatic structure at the landfall of the WR in Northwest Namibia raised speculation about the role of a hotspot during the opening of the South Atlantic ocean. To investigate its deeper velocity structure at the junction of the WR with the African continent was the focus of the amphibious seismological WALPASS experiment. In total 12 ocean-bottom seismometers and 28 broad-band land stations were installed between 2010 and 2012 to acquire seismological data. Here, we present the results of seismic ambient noise tomography to investigate to which extent the Tristan hotspot modified the crustal structure in the landward prolongation of the ridge and in the adjacent oceanic basins. For the tomography, vertical and hydrophone component cross correlations for 〉300 d for OBS stations and between 1 and 2 yr for land stations data were analysed. More than 49 000 velocity measurements (742 dispersion curves) were inverted for group velocity maps at 75 individual signal periods, which then had been inverted for a regional 3-D shear wave velocity model. The resulting 3-D model reveals structural features of the crust related to the continent–ocean transition and its disturbance caused by the initial formation of the WR ∼130 Ma. We found relatively thick continental crust below Northwest Namibia and below the near-shore part of the WR, a strong asymmetry offshore with typical, thin oceanic crust in the Namibe Basin (crossing over into the Angola Basin further offshore) to the North and a wide zone of transitional crust towards the Walvis Basin south of the WR.

Description: The identification of the chemical status of groundwater is a prerequisite for the sustainable management and development of groundwater resources. A better assessment of the chemical status of the groundwater requires the knowledge and understanding of the natural background concentrations to establish threshold values of chemical pollutants in groundwater. The aim of this study is to estimate the natural background levels, the threshold value (TV) of nitrate-nitrogen (NO3--N) and to identify its source in the groundwater in the Bono, Ahafo and Bono East regions of Ghana. A total of 165 groundwater samples were taken from the crystalline and sedimentary aquifers in the study area. Iterative outlier removal technique and a Gaussian mixture model were then used to assess the natural background and threshold nitrate-nitrogen concentrations in the groundwater. Chloride data was then used to trace the NO3-–N source in the groundwater. The estimated NBL of –NO3-–N in the area ranges from [0.001–3.9] mg/L with an expected value of 1.25 mg/L and calculated TV of 6.95 mg/L. The data suggest that NO3-–N concentrations are homogeneous across all the lithologies underlying the study area. The results showed that agricultural, domestic, and denitrification contribute significantly to the loading of NO3-–N concentration in the groundwater. The estimated threshold range of NO3-–N provides the baseline nitrate-nitrogen concentration for future studies in the region. However, the results are inconclusive, and we recommend using isotopic detection (15N-NO3- and 18O- NO3-) in future studies through comprehensive and sustainable regional monitoring of the aquifer system in order to further limit the source of nitrate-nitrogen in the groundwater system.

Description: This dataset provides friction data from ring-shear tests on glass beads with a diameter of 200-300 µm used in analogue modelling of tectonic processes as a rock analogue for “weak” layers in the earth’s upper crust (e.g. Klinkmüller et al., 2016; Ritter et al., 2016; Lohrmann et al., 2003) or as “seismogenic” crust (Rudolf et al., 2022). The glass beads are characterized by means of internal friction coefficients µ and cohesion C. According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of the glass beads are µP = 0.51 , µD = 0.40, and µR = 0.44, respectively (Table 5). Cohesion of the material ranges between 40 Pa and 70 Pa. The material shows a minor rate-weakening of ~1% per ten-fold change in shear velocity v and a stick-slip behaviour at low shear velocities and at high loads.

Description: This dataset provides friction data from ring-shear tests on glass beads with a diameter of 100-200 µm used in analogue modelling of tectonic processes as a rock analogue for “weak” layers in the earth’s upper crust (e.g. Klinkmüller et al., 2016; Ritter et al., 2016; Lohrmann et al., 2003) or as “seismogenic” crust (Rudolf et al., 2022). The glass beads are characterized by means of internal friction coefficients µ and cohesion C. According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of the glass beads are µP = 0.50 , µD = 0.39, and µR = 0.46, respectively (Table 5). Cohesion of the material is close to zero Pa. The material shows a minor rate-weakening of ~1% per ten-fold change in shear velocity v and a stick-slip behaviour at low shear velocities and at high loads.

Description: This dataset provides friction data from ring-shear tests on glass beads with a diameter of less than 50 µm used in analogue modelling of tectonic processes as a rock analogue for “weak” layers in the earth’s upper crust (e.g. Klinkmüller et al., 2016; Ritter et al., 2016; Lohrmann et al., 2003) or as “seismogenic” crust (Rudolf et al., 2022). The glass beads are characterized by means of internal friction coefficients µ and cohesion C. According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of the glass beads are µP = 0.47 , µD = 0.44, and µR = 0.47, respectively (Table 5). Cohesion of the material ranges between 50 Pa and 70 Pa. The material shows a neglectable rate-weakening of 〈1% per ten-fold change in shear velocity v.

Description: The history of sea level across the Quaternary is essential for assessing past and future climate. Global sea-level reconstructions are typically derived from oxygen isotope curves, but require calibration with geological constraints that are scarce prior to the last glacial cycle (〉130 thousand years ago). Here we show that the coral reef terrace sequence at the Huon Peninsula (Papua New Guinea) provides such constraints up to ∼420 thousand years ago, through a geometric analysis of high-resolution topographic data. We derive a northward tectonic tilt as regional deformation pattern, and estimate relative sea level for 31 Quaternary periods, including several periods for which no relative sea level data exists elsewhere. Supported by numerical reef models, these estimates suggest that oxygen isotope-based global mean sea-level curves systematically underestimate interstadial sea-level elevations, by up to ∼20 m. Compared to those curves, our results imply a stronger degree of non-linearity between ice-sheet volumes and global temperatures within Quaternary glacial cycles.

Description: The magnitude of earthquakes on continental normal faults rarely exceeds 7.0 Mw. However, because of their vicinity to large population centers they can be highly destructive. Long recurrence time, relatively small deformations, and limited observations hinder our understanding of the deformation patterns and mechanisms controlling the magnitude of events. Here, this problem is addressed with 2D thermomechanical modeling of normal fault seismic cycles. The 2020 Samos, Greece Mw7.0 earthquake is used as an example as it is one of the largest and most studied continental normal fault earthquakes. The modeling approach employs visco-elasto-plastic rheology, compressibility, free surface, and a rate-and-state friction law for the fault. Modeling of the Samos earthquake suggests the pore fluid pressure ratio on the fault ranges from 0 to 0.7. The model demonstrates that most of the deformation during interseismic and coseismic periods, besides on the fault, occurs in the hanging wall and footwall below the seismogenic part of the fault. The largest vertical surface displacement during the earthquake is the subsidence of the hanging wall in the vicinity of the fault, while the uplift of the footwall and remote part of the hanging wall is significantly smaller. Modeling of the seismic cycles on normal faults with different setups shows the dependency of the magnitude on the thermal profile and dipping angle of the fault; low heat flow and low dipping angle are favorable conditions for the largest events, while steep normal faults in the areas of high heat flow tend to have the smallest magnitudes.

Description: We present a series of analogue models inspired by the geology of the Zürcher Weinland region in the Northern Alpine Foreland Basin of Switzerland to explore the influence of rheological weak, i.e. (partially) ductile layers on the 3D evolution of tectonic deformation. Our model series test the impact of varying weak layer thickness and rheology, as well as different kinematics of an underlying “basal fault”. Model analysis focuses on deformation in the weak layer overburden and, uniquely, within the weak layer itself. We find that for low to moderate basal fault displacements, the above-mentioned parameters strongly influence the degree of coupling between the basal fault and the weak layer overburden. Coupling between the basal fault and overburden decreases by reducing the strength of the weak layer, or by increasing the weak layer’s thickness. As a result, basal fault displacement is less readily transferred through the weak layer, leading to a different structural style in the overburden. By contrast, increasing the amount, or rate, of basal fault slip enhances coupling and leads to a more similar structural style between basal fault and overburden. Moreover, dip-slip displacement on the basal fault is more readily transferred to the overburden than strike-slip displacement of the same magnitude. Our model results compare fairly well to natural examples in the Northern Alpine Foreland Basin, explaining various structural features. These comparisons suggest that rheological weak layers such as the Jurassic Opalinus Clay have exerted a stronger control on fault zone architecture than is commonly inferred, potentially resulting in vertical fault segmentation and variations in structural style. Furthermore, the novel addition of internal marker intervals to the weak layer in our models reveals how complex viscous flow within these layers can accommodate basal fault slip. Our model results demonstrate the complex links between fault kinematics, mechanics and 3D geometries, and can be used for interpreting structures in the Alpine Foreland, as well as in other settings with similar weak layers and basal faults driving deformation in the system.

Description: Basin inversion involves the reversal of subsidence in a basin due to compressional tectonic forces, leading to uplift of the basin's sedimentary infill. Detailed knowledge of basin inversion is of great importance for scientific, societal, and economic reasons, spurring continued research efforts to better understand the processes involved. Analogue tectonic modelling forms a key part of these efforts, and analogue modellers have conducted numerous studies of basin inversion. In this review paper we recap the advances in our knowledge of basin inversion processes acquired through analogue modelling studies, providing an up-to-date summary of the state of analogue modelling of basin inversion. We describe the different definitions of basin inversion that are being applied by researchers, why basin inversion has been historically an important research topic and what the general mechanics involved in basin inversion are. We subsequently treat the wide range of different experimental approaches used for basin inversion modelling, with attention to the various materials, set-ups, and techniques used for model monitoring and analysing the model results. Our new systematic overviews of generalized model results reveal the diversity of these results, which depend greatly on the chosen set-up, model layering and (oblique) kinematics of inversion, and 3D along-strike structural and kinematic variations in the system. We show how analogue modelling results are in good agreement with numerical models, and how these results help researchers to better understand natural examples of basin inversion. In addition to reviewing the past efforts in the field of analogue modelling, we also shed light on future modelling challenges and identify a number of opportunities for follow-up research. These include the testing of force boundary conditions, adding geological processes such as sedimentation, transport, and erosion; applying state-of-the-art modelling and quantification techniques; and establishing best modelling practices. We also suggest expanding the scope of basin inversion modelling beyond the traditional upper crustal “North Sea style” of inversion, which may contribute to the ongoing search for clean energy resources. It follows that basin inversion modelling can bring valuable new insights, providing a great incentive to continue our efforts in this field. We therefore hope that this review paper will form an inspiration for future analogue modelling studies of basin inversion.

Description: The 1989 Mw 6.9 Loma Prieta earthquake is the first major event to occur along the San Andreas fault (SAF) zone in central California since the 1906 M 7.9 San Francisco earthquake. Given the complexity of this event, uncertainty has persisted as to whether this earthquake ruptured the SAF itself or a secondary fault. Recent work on the SAF in the Coachella Valley in southern California has revealed similar complexity, arising from a nonplanar, nonvertical fault geometry, and has led us to reexamine the Loma Prieta event. We have compiled data sets and data analyses in the vicinity of the Loma Prieta earthquake, including the 3D seismic velocity model and aftershock relocations of Lin and Thurber (2012), potential field data collected by the U.S. Geological Survey following the earthquake, and seismic refraction and reflection data from the 1991 profile of Catchings et al. (2004). The velocity model and aftershock relocations of Lin and Thurber (2012) reveal a geometry for the SAF that appears similar to that in the Coachella Valley (although rotated 180°): at Loma Prieta the fault dips steeply near the surface and curves with depth to join the moderately southwest‐dipping main rupture below 6 km depth, itself also nonplanar. The SAF is a clear velocity boundary, with higher velocities on the northeast, attributable to Mesozoic accretionary and other rocks, and lower velocities on the southwest, attributable to Cenozoic sedimentary and volcanic rocks of the La Honda block. Rocks of the La Honda block have been offset right‐laterally hundreds of kilometers from similar rocks in the southern San Joaquin Valley and vicinity, providing evidence that the curved northeast fault boundary of this block is the plate boundary. Thus, we interpret that the Loma Prieta earthquake occurred on the SAF and not on a secondary fault.

Description: Magnetometers are a key component of heliophysics research providing valuable insight into the dynamics of electromagnetic field regimes and their coupling throughout the solar system. On satellites, magnetometers provide detailed observations of the extension of the solar magnetic field into interplanetary space and of planetary environments. At Earth, magnetometers are deployed on the ground in extensive arrays spanning the polar cap, auroral and sub-auroral zone, mid- and low-latitudes and equatorial electrojet with nearly global coverage in azimuth (longitude or magnetic local time—MLT). These multipoint observations are used to diagnose both ionospheric and magnetospheric processes as well as the coupling between the solar wind and these two regimes at a fraction of the cost of in-situ instruments. Despite their utility in research, ground-based magnetometer data can be difficult to use due to a variety of file formats, multiple points of access for the data, and limited software. In this short article we review the Open-Source Python library GMAG which provides rapid access to ground-based magnetometer data from a number of arrays in a Pandas DataFrame, a common data format used throughout scientific research.

Description: Me4+-bearing (Me4+ = Sn, Ti) dravite analogs were synthesized in the system MeO2–MgO–Al2O3–B2O3–SiO2–NaO–H2O at 700 °C and 4 / 0.2 GPa in four hydrothermal experiments. Tourmalines form rosette-like aggregates and needle-like crystals that are chemically homogeneous. Tourmaline crystals obtained in high-pressure runs (4 GPa) are much smaller (up to 0.1 × 2 μm) and have lower Me4+ (0.27 wt. % SnO2, 0.57 wt. % TiO2) than those from the low-pressure (0.2 GPa)runs (up to 1 × 5 μm; 1.77 wt. % SnO2, 2.25 wt. % TiO2). Synthetic analogs of rutile, quartz and coesite were obtained in the system TiO2–MgO–Al2O3–B2O3–SiO2–NaO–H2O, whereas synthetic analogs of cassiterite, tin-rich (up to ~19.55 wt. % SnO2) Na-pyroxene, MgSn(BO3)2 (Mg-analogue of tusionite), quartz and coesite were synthesized in the system SnO2–MgO–Al2O3–B2O3–SiO2–NaO–H2O. We suggest that at a high temperature (≥ 700 ºC), the pressure negatively affects the Ti incorporation into the tourmaline structure. In contrast, at relatively low pressures, the Ti incorporation in tourmaline structures is governed by the Ti content in the mineral-forming medium. Low-pressure conditions are feasible for Sn incorporation in the tourmaline structure. The presence of Ti 4+ and Sn4+ cations in structures of the synthesized tourmalines (probably at octahedrally coordinated sites), is also indicated by changes in the unit-cell parameters.

Description: Since 1991, induced earthquakes have been observed and linked to gas production in the Groningen field. Recorded waveforms are complex, resulting partly from a Zechstein salt layer overlying the reservoir and partly from free‐surface reverberations, internal multiples, interface conversions, guided waves, and waves diving below the reservoir. Therefore, picking of polarities or amplitudes for use in moment tensor inversion is problematic, whereas phase identification may be circumvented employing full waveform techniques. Although moment tensors have become a basic tool to analyze earthquake sources, their uncertainties are rarely reported. We introduce a method for probabilistic moment tensor estimation and demonstrate its use on the basis of a single event within the Groningen field, concentrating on detailed tests of input data and inversion parameters to derive rules of good practice for moment tensor estimation of events recorded in the Groningen field. In addition to the moment tensor, event locations are provided. Hypocenters estimated simultaneously with moment tensors are often less sensitive to uncertainties in crustal structure, which is pertinent for the application to the Groningen field, because the task of relating earthquakes to specific faults hitherto suffers from a limited resolution of earthquake locations. Because of the probabilistic approach, parameter trade‐offs, uncertainties, and ambiguities are mapped. In addition, the implemented bootstrap method implicitly accounts for modeling errors affecting every station and phase differently. A local 1D velocity model extracted from a full 3D velocity model yields more consistent results than other models applied previously. For all velocity models and combinations of input data tested, a shift in location of 1 km to the south is observed for the test event compared to the public catalog. A full moment tensor computed employing the local 1D velocity model features negative isotropic components and may be interpreted as normal fault and collapse at reservoir level.

Description: Mg-carbonate is one of the main carbonates subducting from the Earth’s surface into the mantle and possible reactions of this compound with the main mantle minerals determine the stability of carbonates into the Earth’s mantle. Recently, we have theoretically shown that at pressures and temperatures of the Earth’s lower mantle MgCO3 should react with MgO, producing Mg2CO4. Here, using diamond anvil cell technique, we have performed in situ investigation of the product of MgCO3+MgO reaction at pressures around 50 GPa and temperatures above 2000 K. Investigation of Raman and X-ray diffraction patterns unambiguously indicates that reaction has been realized and as the reaction product we suggest the modification similar to M-g2CO4-P21/c. Using the transmission electron microscopy technique, we show the presence of the new Mg-orthocarbonate/carbonate phase in the sample extracted from high-pressure environment.

Description: Tropical Lake Sentani in the Indonesian Province Papua consists of four separate basins and is surrounded by a catchment with a very diverse geology. We characterized the surface sediment (upper 5 cm) of the lake’s four sub-basins based on multivariate statistical analyses (principal component analysis, hierarchical clustering) of major element compositions obtained by X-ray fluorescence scanning. Three types of sediment are identified based on distinct compositional differences between rivers, shallow/proximal and deep/distal lake sediments. The different sediment types are mainly characterized by the correlation of elements associated with redox processes (S, Mn, Fe), carbonates (Ca), and detrital input (Ti, Al, Si, K) derived by river discharge. The relatively coarse-grained river sediments mainly derive form the mafic catchment geology and contribution of the limestone catchment geology is only limited. Correlation of redox sensitive and detrital elements are used to reveal oxidation conditions, and indicate oxic conditions in river samples and reducing conditions for lake sediments. Organic carbon (TOC) generally correlates with redox sensitive elements, although a correlation between TOC and individual elements change strongly between the three sediment types. Pyrite is the quantitatively dominant reduced sulfur mineral, monosulfides only reach appreciable concentrations in samples from rivers draining mafic and ultramafic catchments. Our study shows large spatial heterogeneity within the lake’s sub-basins that is mainly caused by catchment geology and topography, river runoff as well as the bathymetry and the depth of the oxycline. We show that knowledge about lateral heterogeneity is crucial for understanding the geochemical and sedimentological variations recorded by these sediments. The highly variable conditions make Lake Sentani a natural laboratory, with its different sub-basins representing different depositional environments under identical tropical climate conditions.

Description: Along the Northern Chilean active continental margin, the subducting Nazca plate is characterized by a rough sea floor topography that has been suggested to control the rupture behaviour of megathrust earthquakes. However, there is still debate of what structures exactly controlled the extent of the rupture of the Mw 8.12014 April 1st Iquique earthquake and why it only broke 1/3 of a large seismic gap that last ruptured completely in 1877. To better understand the seismotectonic segmentation of the northern Chilean convergent margin, we use datasets from different geophysical and geodetic studies in this area to produce a 3D model. We combine depth migrated images of the two northernmost multi-channel seismic reflection CINCA’95 (Crustal Investigations off- and onshore Nazca Plate/Central Andes) lines, bathymetry data, coseismic slip models, geodetic coupling, seismic b values, relocated seismic events and the morphology of the subduction interface from gravity modelling. The interface morphology shows a prominent surface relief that spacially correlates with the rupture process of the mainshock on April 1st and also for the largest aftershock on April 3rd. The main slip area exhibits a strong correlation with a large elongated topographic depression of the subducting slab. An elongated topographic high on the subducting plate to the south of that depression correlates with low pre-seismic locking and very likely acted as a barrier for rupture propagation for the main shock, as well as for the largest after shock. A subducted circular topographic high of 25 km in diameter located updip of the rupture area, possibly prevented coseismic slip to rupture all the way up to the trench axis. Thus, our observations support that subducting sea floor morphology plays an important role controlling rupture processes.

Description: A temporary seismic network consisting of 48 long-term and 15 short-term stations was deployed from June 2021 to June 2022. The network comprises 27 broadband stations and 20 short period geophones from the Ruhr-University Bochum, the Geophysical Instrument Pool Potsdam (GIPP) and the RWTH Aachen. The inter-station spacing of the longer-term network is about 2 km and the total extent of the network is about 20 km. The densely populated area and vicinity of active pit mining demanded a balance between dense station placement and avoidance of anthropogenic noise sources. The network serves as a pre-study for the installment of a field laboratory in Eschweiler-Weisweiler, Germany. Details can be found in the accompanying data publication (Finger et al., in preparation). This project has been subsidized through the Cofund GEOTHERMICA, which is supported by the European Union’s HORIZON 2020 programme for research, technological development and demonstration under grant agreement No 731117. Furthermore, this study was supported by the Interreg North-West Europe (Interreg NWE) Programme through the Roll-out of Deep Geothermal Energy in North-West Europe (DGE-ROLLOUT) Project (http://www.nweurope.eu/DGE-Rollout), NWE 892. The Interreg NWE Programme is part of the European Cohesion Policy and is financed by the European Regional Development Fund (ERDF). Waveform data are available from the GEOFON data centre, under network code ZB. Data from some stations are embargoed until Januar 2026 but might be available on request.

Description: A sequence of three strong (M W 7.2–6.4) and several moderate (M W 4.4–5.7) earthquakes struck the Pamir Plateau and surrounding mountain ranges of Tajikistan, China, and Kyrgyzstan in 2015–2017. With a local seismic network in operation in the Xinjiang province since August 2015, an aftershock network on the Pamir Plateau of Tajikistan since February 2016, and additional permanent regional seismic stations, we were able to record the succession of the fore-, main-, and aftershock sequences at local distances with good azimuthal coverage. We located 11,784 seismic events and determined the moment tensor for 33 earthquakes. The seismicity delineates the major tectonic structures of the Pamir, i.e., the thrusts that absorb shortening along the plateau thrust front, and the strike-slip and normal faults that dissect the Plateau into a westward extruding and a northward advancing block. Fault ruptures were activated subsequently at increasing distances from the initial M W 7.2 Sarez. All mainshock areas but the initial one exhibited foreshock seismicity which was not modulated by the occurrence of the earlier earthquakes. The tabular ASCII data of the seismic event catalog consist of origin date, time, location, depth and magnitude of the events, along with the quality measures: number of P- and S-wave arrival time picks, location root-mean-square misfit and localization method. The tabular ASCII data of the moment tensor catalog consist of origin date, time, location, the six independent components of the moment tensor, the moment magnitude, and the orientation of the preferred fault plane parameterized as fault strike, dip and rake.

Description: In this study, we explored the capability of coda wave interferometry (CWI) for monitoring CO2 storage by estimating the seismic velocity changes caused by CO2 injection. Given that the CWI method is highly efficient, the primary aim of this study was to provide a quick detection tool for the long-term monitoring of CO2 storage safety. In particular, we looked at monitoring with a cross-well geometry. We also expected that CWI could help to reduce the inversion errors of existing methods. Time-lapse upgoing waves and downgoing waves from two-component datasets were utilized to efficiently monitor the area between the wells and provide a quick indication of possible CO2 leakage. The resulting mean velocity changes versus the depth indicated the depth where velocity changes occurred. Combining the upgoing and downgoing wavefields provided a more specific indication of the depth range for changes. The calculated velocity changes were determined using the time shift between the time-lapse wavefields caused by CO2 injection/leakage. Hence, the resulting velocity changes were closely related to the ratio of propagation path length through the CO2 injection/leakage layer over the length of the entire travel path. The results indicated that the noise level and repeatability of the time-lapse datasets significantly influenced the results generated using CWI. Therefore, denoising and time-lapse processing were very important for improving the detectability of any change. Applying CWI to time-lapse cross-well surveys can be an effective tool for monitoring CO2 in the subsurface at a relatively low computational cost. As a highly efficient monitoring method, it is sensitive to changes in the seismic response caused by velocity changes in the subsurface and provides additional constraints on the inversion results from conventional travel time tomography and full waveform inversion.

Description: Understanding physical processes prior and during eruptions remains challenging, due to uncertainties about subsurface structures and undetected processes within the volcano. Here, the authors use a dedicated fibre-optic cable to obtain strain data and identify volcanic events and image hidden near-surface volcanic structural features at Etna volcano, Italy. In the paper Jousset et al. (2022), we detect and characterize strain signals associated with explosions, and we find evidences for non-linear grain interactions in a scoria layer of spatially variable thickness. We also demonstrate that wavefield separation allows us to incrementally investigate the ground response to various excitation mechanisms, and we identify very small volcanic events, which we relate to fluid migration and degassing. We recorded seismic signals from natural and man-made sources with 2-m spacing along a 1.5-km-long fibre-optic cable layout near the summit of actives craters of Etna volcano, Italy. Those results provide the basis for improved volcano monitoring and hazard assessment using DAS. This data publication contains the full data set used for the analysis. This data set comprises strain-rate data from 1 iDAS interrogator (~750 traces), velocity data from 15 geophones and 4 broadband seismometers, and infrasonic pressure data from infrasound sensors. For further explanation of the data and related processing steps, please refer to Jousset et al. (2022).

Description: The goal of Inter-Wind is to investigate and predict the induced seismic signals of wind turbines at different locations in Southern Germany. The experiments involve various sensor types and data loggers.

Description: We compiled a dataset of continuous recordings from the temporary and permanent seismic networks to compute the high-resolution 3D S-wave velocity model of the Southeastern Alps, the western part of the external Dinarides, and the Friuli and Venetian plains through ambient noise tomography. Part of the dataset is recorded by the SWATH-D temporary network and permanent networks in Italy, Austria, Slovenia and Croatia between October 2017 and July 2018. We computed 4050 vertical component cross-correlations to obtain the empirical Rayleigh wave Green’s functions. The dataset is complemented by adopting 1804 high-quality correlograms from other studies. The fast-marching method for 2D surface wave tomography is applied to the phase velocity dispersion curves in the 2–30 s period band. The resulting local dispersion curves are inverted for 1D S-wave velocity profiles using the non-perturbational and perturbational inversion methods. We assembled the 1D S-wave velocity profiles into a pseudo-3D S-wave velocity model from the surface down to 60 km depth. A range of iso-velocities, representing the crystalline basement depth and the crustal thickness, are determined. We found the average depth over the 2.8–3.0 and 4.1–4.3 km/s iso-velocity ranges to be reasonable representations of the crystalline basement and Moho depths, respectively. The basement depth map shows that the shallower crystalline basement beneath the Schio-Vicenza fault highlights the boundary between the deeper Venetian and Friuli plains to the east and the Po-plain to the west. The estimated Moho depth map displays a thickened crust along the boundary between the Friuli plain and the external Dinarides. It also reveals a N-S narrow corridor of crustal thinning to the east of the junction of Giudicarie and Periadriatic lines, which was not reported by other seismic imaging studies. This corridor of shallower Moho is located beneath the surface outcrop of the Permian magmatic rocks and seems to be connected to the continuation of the Permian magmatism to the deep-seated crust. We compared the shallow crustal velocities and the hypocentral location of the earthquakes in the Southern foothills of the Alps. It revealed that the seismicity mainly occurs in the S-wave velocity range between ∼3.1 and ∼3.6 km/s.

Description: The dataset contains SEG-Y data of a 3D seismic in situ experiment in the Mont Terri URL, Switzerland. The data were acquired using a pneumatic impact source and 3-C geophones, installed in boreholes or on the tunnel wall. The data publication covers the raw data (individual hits per shot point) and the vertically stacked data stored in SEG-Y format. The survey geometry (source coordinates, receiver coordinates) is included.

Description: Modern continental crust has evolved to a more potassic, granitic composition than early continental crust, which comprises largely sodic TTG-suite magmas. The present paradigm holds that the latter are largely “juvenile” (in the sense that the time from mantle extraction to felsic crust production is comparatively short, of the order 10–100 Ma) while the former represent recycled older crust of igneous or sedimentary composition. The data from high-Mg diorites, tonalites, granodiorites and potassic granites of the 125–115 Ma Menglian Batholith (SE Tibet) exemplify the modern situation and can therefore be used to constrain current crust formation processes. These rocks have higher concentrations of incompatible elements than magmatic rocks from typical continental arc settings, with a continuum of increasing K2O/Na2O ratios, SiO2, K2O, Rb, and Th concentrations juxtaposed with decreasing MgO, CaO, and Sr. They consistently record both higher zircon δ18O values than mantle values and decoupled Ndsingle bondHf isotope systems caused by the interaction of subducted sediments with the mantle wedge. Petrogenetic mechanisms that connect the suite include crystal fractionation within the diorites, melting of the lower crust induced by advection of heat and water by the diorites, and high-level fractionation of the tonalite-granodiorite suite to produce the high-silica granites. Therefore, this example of modern fertile continental crust had a five-stage evolution: (1) subduction-enrichment of the mantle source, (2) mantle melting to produce mafic magmas that pooled in or below the lower crust, (3) mafic magma differentiation to produce the tonalite-granodioritic magmas controlled by crystal-liquid equilibria, (4) crustal melting and admixture to the evolving felsic magmas and (5) final high-level fractionation and melt extraction to produce the silicic extreme, enriched in incompatible elements such as Rb, Th and K. This model could be a general mechanism for how modern mature continental crust evolves. Importantly, it indicates a significant role for mafic magmas and thence a more important role for juvenile additions than is generally accepted.

Description: Advanced geodetic and astronomical tasks, such as precise positioning and navigation require forecasted Earth Orientation Parameters (EOP). The Second Earth Orientation Parameters Prediction Comparison Campaign (2nd EOP PCC) aims to compare various EOP forecast methods implemented by different institutes from all over the world. Here we focus on universal time (UT1-UTC) and Length-of-Day (LOD) predictions received in the period between September 1st, 2021 and May 29th, 2022. The forecasts are preliminarily evaluated against the EOP 14 C04 solution delivered by the International Earth Rotation and Reference System Service (IERS) by using the mean absolute error (MAE) as the prediction quality measure. Exemplarily, we compare forecasts from IERS delivered by U.S. Naval Observatory (USNO) and a selected campaign participant to assess the impact of both input data and computation methodology on predictions. We show that improper treatment of long-periodic ocean tides has severely degraded LOD forecasting until this issue has been brought to the attention of the participant during a meeting of the 2nd EOP PCC. We consider this as a good example for the benefit of the campaign to the overall scientific community by providing specific feedback to individual processing centres on deficits in their products, which lead to quick and effective adaptations. The lessons learned from this analysis could be applied to other EOP forecasting methods based on Effective Angular Momentum (EAM) predictions.

Description: Geothermal exploration will help move towards a low-carbon economy and provide a basis for green and sustainable growth. The development of new practical, reliable methods for geophysical characterization of a reservoir has the potential to facilitate a broader application of deep geothermal energy. At the Groß Schönebeck in situ laboratory, a unique vertical seismic profiling (VSP) dataset was recorded in two 4.3 km deep geothermal boreholes using fibre-optic cables in early 2017. The experiment set-up consisted of 61 vibrator points organized in a spiral pattern around the well site to ensure a proper offset and azimuth distribution in the target reservoir section. Data were processed using a standard workflow for VSP. As a result, a detailed three-dimensional  km image around the existing boreholes was created using the Kirchhoff migration algorithm with restricted aperture. The imaging resolved small-scale features in the reservoir essential for the future exploration of the geothermal research site. Borehole data with vertical resolution up to 16 m revealed the existing depth variations of the Elbe reservoir sandstone horizon at 4.08–4.10 km depth and indications of an unconformity in the area where we expect volcanic rocks. In addition, in the borehole data a complex interlaying with numerous pinch-outs in the Upper Rotliegend reservoir section (3.8 to 4 km depth) was discovered. Thereby, we demonstrate that wireline fibre-optic data can significantly contribute to exploration by providing an efficient and reliable method for deep geothermal reservoir imaging.

Description: Salt deposits offer a variety of usage types. These include the mining of rock salt and potash salt as important raw materials, the storage of energy in man-made underground caverns, and the disposal of hazardous substances in former mines. The most serious risk with any of these usage types comes from the contact with groundwater or surface water. It causes an uncontrolled dissolution of salt rock, which in the worst case can result in the flooding or collapse of underground facilities. Especially along potash seams, cavernous structures can spread quickly, because potash salts show a much higher solubility than rock salt. However, as their chemical behavior is quite complex, previous models do not account for these highly soluble interlayers. Therefore, the objective of the present thesis is to describe the evolution of cavernous structures along potash seams in space and time in order to improve hazard mitigation during the utilization of salt deposits. The formation of cavernous structures represents an interplay of chemical and hydraulic processes. Hence, the first step is to systematically investigate the dissolution and precipitation reactions that occur when water and potash salt come into contact. For this purpose, a geochemical reaction model is used. The results show that the minerals are only partially dissolved, resulting in a porous sponge like structure. With the saturation of the solution increasing, various secondary minerals are formed, whose number and type depend on the original rock composition. Field data confirm a correlation between the degree of saturation and the distance from the center of the cavern, where solution is entering. Subsequently, the reaction model is coupled with a flow and transport code and supplemented by a novel approach called ‘interchange’. The latter enables the exchange of solution and rock between areas of different porosity and mineralogy, and thus ultimately the growth of the cavernous structure. By means of several scenario analyses, cavern shape, growth rate and mineralogy are systematically investigated, taking also heterogeneous potash seams into account. The results show that basically four different cases can be distinguished, with mixed forms being a frequent occurrence in nature. The classification scheme is based on the dimensionless numbers Péclet and Damköhler, and allows for a first assessment of the hazard potential. In future, the model can be applied to any field case, using measurement data for calibration. The presented research work provides a reactive transport model that is able to spatially and temporally characterize the propagation of cavernous structures along potash seams for the first time. Furthermore, it allows to determine thickness and composition of transition zones between cavern center and unaffected salt rock. The latter is particularly important in potash mining, so that natural cavernous structures can be located at an early stage and the risk of mine flooding can thus be reduced. The models may also contribute to an improved hazard prevention in the construction of storage caverns and the disposal of hazardous waste in salt deposits. Predictions regarding the characteristics and evolution of cavernous structures enable a better assessment of potential hazards, such as integrity or stability loss, as well as of suitable mitigation measures.

Description: Salzlagerstätten bieten eine Vielzahl an Nutzungsmöglichkeiten. Diese umfassen den Abbau von Steinsalz und Kalisalz als wichtige Rohstoffe, die Speicherung von Energie in künstlich erzeugten Hohlräumen, sowie die Entsorgung gefährlicher Substanzen in stillgelegten Bergwerken. Die größte Gefahr bei jeder dieser Nutzungsarten ist der Kontakt mit Grund- oder Oberflächenwasser. Er bewirkt eine unkontrollierte Lösung des Salzgesteins, was im schlimmsten Fall zur Flutung oder zum Einsturz unterirdischer Infrastrukturen führt. Insbesondere entlang von Kaliflözen können sich kavernöse Strukturen schnell ausbreiten, da Kalisalze eine wesentlich höhere Löslichkeit besitzen als Steinsalz. Ihr chemisches Verhalten ist jedoch komplex, weshalb bisherige Modelle diese hochlöslichen Zwischenschichten vernachlässigen. Ziel der vorliegenden Doktorarbeit ist es daher, die Ausbreitung kavernöser Strukturen entlang von Kaliflözen räumlich und zeitlich zu beschreiben und damit die Möglichkeiten zur Gefahrenprävention bei der Nutzung von Salzlagerstätten zu verbessern. Die Bildung kavernöser Strukturen ist ein Zusammenspiel chemischer und hydraulischer Prozesse. Zunächst wird daher mithilfe eines geochemischen Reaktionsmodells systematisch untersucht, welche Lösungs- und Fällungsreaktionen beim Kontakt von Wasser und Kalisalz auftreten. Die Ergebnisse zeigen, dass nur ein Teil der Minerale gelöst wird, wodurch sich eine poröse, schwammartige Struktur bildet. Mit zunehmender Aufsättigung der Lösung treten verschiedene Sekundärminerale auf, deren Anzahl und Art vom Ausgangsgestein abhängen. Felddaten belegen dabei eine Korrelation zwischen Sättigungsgrad und Abstand vom Kavernenzentrum, wo die Lösung ein- und austritt. Anschließend wird das Reaktionsmodell mit einem Strömungs- und Transportcode gekoppelt und um einen neuartigen Ansatz namens "interchange" ergänzt. Dieser ermöglicht den Austausch von Lösung und Gestein zwischen Bereichen unterschiedlicher Porosität und Mineralogie, und damit letztlich das Wachstum der kavernösen Struktur. In mehreren Szenarienanalysen werden Kavernenform, Ausbreitungsgeschwindigkeit und Mineralogie systematisch untersucht und dabei auch heterogene Kaliflöze betrachtet. Die Ergebnisse zeigen, dass grundsätzlich vier Fälle zu unterscheiden sind, wobei in der Natur häufig Mischformen auftreten. Die Klassifizierung erfolgt auf Basis der dimensionslosen Kennzahlen Péclet und Damköhler und ermöglicht eine erste Abschätzung des Gefahrenpotentials. In Zukunft kann das Modell auf beliebige Feldbeispiele angewandt und mithilfe von Messdaten kalibriert werden. Die vorliegende Arbeit liefert ein reaktives Transportmodell, mit dem die Ausbreitung kavernöser Strukturen entlang von Kaliflözen erstmals räumlich und zeitlich beschrieben werden kann. Auch Mächtigkeit und Zusammensetzung der Übergangszone zwischen Kavernenzentrum und unberührtem Salzgestein können damit bestimmt werden. Letzteres ist insbesondere im Kalibergbau von Bedeutung, um natürliche kavernöse Strukturen rechtzeitig zu lokalisieren und damit das Risiko für eine Flutung von Bergwerken zu verringern. Auch bei der Herstellung von Speicherkavernen und der Einlagerung gefährlicher Substanzen im Salzgestein können die Modelle zu einer besseren Gefahrenprävention beitragen. Sie ermöglichen Prognosen über Beschaffenheit und Ausbreitungsverhalten kavernöser Strukturen, wodurch sowohl potentielle Gefahren, wie der Verlust von Dichtigkeit oder Stabilität, als auch geeignete Gegenmaßnahmen besser abschätzbar werden.

Description: Since the nineteen-eighties, the depth, number, position and shape of the heat sources feeding the super-hot geothermal system of the Los Humeros caldera (Mexico) is under debate. With the aim of providing a seismic constraint of this region, we present a high resolution three-dimensional anisotropic shear wave velocity model. We used the continuous records of ambient seismic noise at 45 seismic stations deployed for more than one year. From the data, we obtained a set of about 1444 phase and 1534 group velocity dispersion curves, for Love and Rayleigh waves, respectively. By using the dispersion data, we obtained three dimensional models for shear wave velocities and radial anisotropy down to 17 km of depth. These models allowed to image three low velocity bodies at different depths: 1) a deep storage of potential molten material rising from the depth and stopping at ~11 km of depth, 2) a second storage region from 3 to 8 km of depth, related with the Los Humeros caldera collapse, and that feeds the 3) shallow low-velocity bodies between 1.3 and 2.2 km, representing the expression of the geothermal reservoir currently exploited. All these low velocity bodies are interconnected and represent part of the remnant magmatic plumbing system beneath the Los Humeros caldera. These seismic images provide insights to the deep upward pathways of fluids feeding the geothermal reservoir from the heat source(s) and its relationship with the structures controlling the hydrothermal system. Previous article in issue

Description: A dense seismological array and profile reveal the deep structure across the Longmenshan from the Songpan-Ganzi terrane of the Tibetan plateau to the Sichuan basin. Receiver function and tomographic images reveal that the Pengguan Complex which cores the Longmenshan in the region where the Ms. 8 Wenchuan earthquake of 2008 occurred, is marked by high velocities in the upper 15 km of the crust. At about 15 km depth both P- and S-wave velocities decrease at a flat-lying boundary around which the aftershock hypocentres of the Wenchuan earthquake are concentrated. Thus, this boundary may be a faulted interface or detachment, marking the base of the Pengguan Complex. Moho depths change significantly in going from the Tibetan plateau to the Sichuan basin. At the location of the dense profile a Moho step occurs, located about 50 km NW of the surface trace of the Yingxiu-Beichuan fault (YBF). The boundary at about 15 km depth below the Pengguan Complex seems to deepen at around the Wenchuan-Maoxian fault (WMF) by about 3 km and merge to the NW with another interface at about 18 km depth. This interface, NW of the WMF, which correlates with the top of a zone of high conductivity is interpreted to represent the top of the Tibetan mid-crustal low velocity, high conductivity zone. The tomographic image indicates that the boundary between the low velocities of the Songpan-Ganzi terrane and the high velocities of the Sichuan basin in the middle and lower crust occurs NW of the surface trace of the YBF. Thus, it is proposed that a zone extending from the WMF at about 15 km depth to the Moho step about 25 km further NW marks the boundary between the Tibetan plateau and the Sichuan basin in the middle and lower crust.

Description: The 100 km wide Mérida Andes extend from the Colombian/Venezuelan border to the Coastal Cordillera. The mountain chain and its associated major strike-slip fault systems in western Venezuela formed due to oblique convergence of the Caribbean with the South American Plates and the north-eastwards expulsion of the North Andean Block. Due to the limited knowledge of lithospheric structures related to the formation of the Mérida Andes research projects have been developed to illuminate this zone with deep geophysical data. In this study, we present three-dimensional inversion of broadband magnetotelluric data, collected along a 240 km long profile crossing the Mérida Andes and the Maracaibo and Barinas–Apure foreland basins. The distribution of the stations limits resolution of the model to off-profile features. Combining 3D inversion of synthetic data sets derived from 3D modelling with 3D inversion of measured data, we could derive a 10 to 15 km wide corridor with good lateral resolution to develop hypotheses about the origin of deep-reaching anomalies of high electrical conductivity. The Mérida Andes appear generally as electrically resistive structures, separated by anomalies associated with the most important fault systems of the region, the Boconó and Valera faults. Sensitivity tests suggest that the Valera Fault reaches to depths of up to 12 km and the Boconó Fault to more than 35 km depth. Both structures are connected to a sizeable conductor located east of the profile at 12–15 km depth. We propose that the high conductivity associated with this off-profile conductor may be related to the detachment of the Trujillo Block. We also identified a conductive zone that correlates spatially with the location of a gravity low, possibly representing a SE tilt of the Maracaibo Triangular Block under the mountain chain to great depths (30 km). The relevance of these tectonic blocks in our models at crustal depths seems to be consistent with proposed theories that describe the geodynamics of western Venezuela as dominated by floating blocks or orogens. Our results stress the importance of the Trujillo Block for the current tectonic evolution of western Venezuela and confirm the relevance of the Boconó Fault carrying deformation to the lower crust and upper mantle. The Barinas–Apure and the Maracaibo sedimentary basins are imaged as electrically conductive with depths of 4 to 5 km and 5 to 10 km, respectively. The Barinas–Apure basin is imaged as a simple 1D structure, in contrast to the Maracaibo Basin, where a series of conductive and resistive bodies could be related to active deformation causing the juxtaposition of older geological formations and younger basin sediments.

Description: Most tectonic models consider that the “Samail subduction zone” was the only subduction zone at the mid-Cretaceous convergent Arabian margin. We report four new Rb-Sr multimineral isochron ages from high-pressure (HP) rocks and a major shear zone of the uppermost Ruwi-Yiti Unit of the Saih Hatat window in the Oman Mountains of NE Arabia. These ages demand a reassessment of the intraoceanic suprasubduction-zone evolution that formed the Samail Ophiolite and its metamorphic sole in the Samail subduction zone. Our new ages constrain waning HP metamorphism of the Ruwi subunit at ∼99-96 Ma and associated deformation in the Yenkit shear zone between ∼104 and 93 Ma. Our ages for late stages of deformation and HP metamorphism (thermal gradients of ∼8–10°C km−1) overlap with published ages of ∼105-102 Ma for Samail-subduction-zone prograde-to-peak metamorphism (thermal gradients of ∼20–25°C km−1), subsequent decompressional partial melting of the metamorphic sole and suprasubduction-zone crystallization of the Samail Ophiolite (thermal gradients of ∼30°C km−1) between ∼100 and 93 Ma. Thermal considerations demand that two subduction zones existed at the mid-Cretaceous Arabian margin. High-pressure metamorphism of the Ruwi-Yiti rocks occurred in a mature, thermally equilibrated “Ruwi subduction zone” that formed at ∼110 Ma. Initiation of the infant, thermally unequilibrated and, thus, immature, outboard intraoceanic Samail subduction zone occurred at ∼105 Ma. The Samail Ophiolite and its metamorphic sole were then thrust over the exhuming Ruwi-Yiti HP rocks and onto the Arabian margin after ∼92 Ma, while the bulk of the Saih Hatat HP rocks below the Ruwi-Yiti Unit started to be underthrust in the Ruwi subduction zone.

Description: Ambient seismic noise tomography is a novel, low-impact method for investigating the earth's structure. Although most passive seismic studies focus on structures on crustal scales, there are only a few examples of this technique being applied in a mineral exploration context. In this study, we performed an ambient seismic experiment to ascertain the relationship between the shallow shear wave velocity and mineralized zones in the Erzgebirge in Germany, one of the most important metal provinces in Europe. Late Variscan mineralized greisen and veins occurring in the Geyer-Ehrenfriedersdorf mining district of the Central Erzgebirge were mined from medieval times until the end of the 19th century. These occurrences represent a significant resource for commodities of high economic importance, such as tin, tungsten, zinc, indium, bismuth and lithium. Based on ambient noise data from a dense “LARGE-N” network comprising 400 low-power, short-period seismic stations, we applied an innovative tomographic inversion technique based on Bayesian statistics (transdimensional, hierarchical Monte Carlo search with Markov Chains using a Metropolis/Hastings sampler) to derive a three-dimensional shear wave velocity model. An auxiliary 3D airborne time-domain electromagnetic dataset is used to provide additional insight into the subsurface architecture of the area. The velocity model shows distinct anomalies down to approximately 500 m depth that correspond to known geological features of the study area, such as (a) gneiss intercalations in the mica schist-dominated host rock, imaged by a SW–NE striking low-velocity zone with a moderately steep northerly dip, and (b) a NW-trending strike-slip fault, imaged as a subvertical linear zone cross-cutting and offsetting this low-velocity domain. Similar to the velocity data, the electromagnetic data exhibit north-dipping (high-conductivity) structures in the mica schists, corresponding to the strike and dip of the predominant metamorphic fabric. An unsupervised classification performed on the bivariate 3D dataset yielded nine spatially coherent classes, one of which shows a high correspondence with drilled greisen occurrences in the roof zone of a granite pluton. The relatively high mean shear velocity and resistivity values of this class could be explained by changes in density and composition during greisen formation, as observed in other areas of the Erzgebirge. Our study demonstrates the great potential of the cost-efficient and low-impact ambient noise technology for mineral exploration, especially when combined with other independent geophysical datasets.

Description: In this study, 3-D models of P-wave velocity (Vp) and P- and S-wave ratio (Vp/Vs) of the crust and upper mantle in the Eastern and eastern Southern Alps (northern Italy and southern Austria) were calculated using local earthquake tomography (LET). The dataset includes high-quality arrival-times from well-constrained hypocenters observed by the dense, temporary seismic networks of the AlpArray AASN and SWATH-D. The resolution of the LET was checked by synthetic tests and analysis of the Model Resolution Matrix. The small inter-station spacing (average of ∼15 km within the SWATH-D network) allowed us to image crustal structure at unprecedented resolution across a key part of the Alps. The derived P velocity model revealed a highly heterogeneous crustal structure in the target area. One of the main findings is that the lower crust is thickened, forming a bulge at 30-50 km depth just south of and beneath the Periadriatic Fault and the Tauern Window. This indicates that the lower crust decoupled both from its mantle substratum as well as from its upper crust. The Moho, taken to be the iso-velocity contour of Vp=7.25 km/s, agrees with the Moho depth from previous studies in the European and Adriatic forelands. It is shallower on the Adriatic side than on the European side. This is interpreted to indicate that the European Plate subducted beneath the Adriatic Plate in the Eastern and eastern Southern Alps.

Description: We present results derived from a seismic refraction experiment and gravity measurements about the crustal structure of southern Sri Lanka and the adjacent Indian Ocean. A P-wave velocity model was derived using forward modelling of the observed travel times along a 509 km long, N-S trending profile at 81°E longitude. Our results show that the continental crust below southern Sri Lanka is up to 38 km thick. A ~ 65 km wide transition zone, which thins seawards to ~7 km thickness, divides stretched continental from oceanic crust. The adjacent, 4.7 to 7 km thick normal oceanic crust is covered by up to 4 km thick sediments. The oceanic crust is characterized by intra-crustal reflections and displays P-wave velocity variations, especially in oceanic layer 2, along our profile. In the central part of the profile, the uppermost mantle layer is characterized by normal P-wave mantle velocities of 8.0–8.1 km/s. At the southern end of the profile, unusual low upper mantle seismic velocities, ranging from 7.5 to 7.6 km/s only, characterize the uppermost mantle layer. These low upper mantle velocities are probably caused by partially serpentinized upper mantle. At even greater depths the upper mantle layer is characterized by velocities of 8.3 km/s on average. The type of margin along our profile is difficult to identify, since it is characterized by features typical for different types of margins.

Description: The TTZ-South seismic profile follows the Teisseyre-Tornquist zone (TTZ) at the SW margin of the East European craton (EEC). Investigation results reveal the upper lithospheric structure as representing the NW-vergent, NE-SW striking overthrust-type, Paleoproterozoic (~1.84–1.8 Ga) Fennoscandia-Sarmatia suture. The Sarmatian segment of the EEC comprises two crustal-scale tectonic thrust slices: the Moldavo-Podolian and Lublino-Volhynian basement units, overriding the northerly located Lysogoro-Radomian unit of Fennoscandian affinity. The combined results of the TTZ-South and other nearby deep seismic profiles are consistent with a continuation of the EEC cratonic basement across the TTZ to the SW and its plunging into the deep substratum of the adjacent Paleozoic platform. Extensional deformation responsible for the formation of the mid to late Proterozoic (~1.4–0.6 Ga), SW-NE trending Orsha-Volhynia rift basin is probably also recorded. The thick Ediacaran succession deposited in the rift was later tectonically thickened due to Variscan deformation. The Moho depth varies between 37 and 49 km, resulting in the thinnest crust in the SE, sharp depth changes across the TTZ, and slow shallowing from 49 to 43 km to the NW. The abrupt Moho depth increase from 43 to 49 km is considered to reflect the overlying lower crust tectonic duplication within the suture zone.

Description: The region of West Bohemia and Upper Palatinate belongs to the West Bohemian Massif. The study area is situated at the junction of three different Variscan tectonic units and hosts the ENE-WSW trending Ohře Rift as well as many different fault systems. The entire region is characterized by ongoing magmatic processes in the intra-continental lithospheric mantle expressed by a series of phenomena, including e.g. the occurrence of repeated earthquake swarms and massive degassing of mantle derived CO2 in form of mineral springs and mofettes. Ongoing active tectonics is mainly manifested by Cenozoic volcanism represented by different Quaternary volcanic structures. All these phenomena make the Ohře Rift a unique target area for European intra-continental geo-scientific research. With magnetotelluric (MT) measurements we image the subsurface distribution of the electrical resistivity and map possible fluid pathways. Two-dimensional (2D) inversion results by Muñoz et al. (2018) reveal a conductive channel in the vicinity of the earthquake swarm region that extends from the lower crust to the surface forming a pathway for fluids into the region of the mofettes. A second conductive channel is present in the south of their model; however, their 2D inversions allow ambiguous interpretations of this feature. Therefore, we conducted a large 3D MT field experiment extending the study area towards the south. The 3D inversion result matches well with the known geology imaging different fluid/magma reservoirs at crust-mantle depth and mapping possible fluid pathways from the reservoirs to the surface feeding known mofettes and spas. A comparison of 3D and 2D inversion results suggests that the 2D inversion results are considerably characterized by 3D and off-profile structures. In this context, the new results advocate for the swarm earthquakes being located in the resistive host rock surrounding the conductive channels; a finding in line with observations e.g. at the San Andreas Fault, California.

Description: This data set includes digital image correlation data from analog earthquakes experiments. The data consists of grids of surface strain and time series of surface displacement (horizontal and vertical) and strain. The data have been derived using a stereo camera setup and processed with LaVision Davis 10 software. Detailed descriptions of the experiments and results regarding the surface pattern of the strain can be found in Kosari et al. (in review), to which this data set is supplementary. We use an analog seismotectonic scale model approach (Rosenau et al., 2019 and 2017) to generate a catalog of analog megathrust earthquakes (Table 1). The presented experimental setup is modified from the 3D setup used in Rosenau et al. (2019) and Kosari et al. ( 2020). The subduction forearc model wedge is set up in a glass-sided box (1000 mm across strike, 800mm along strike, and 300 mm deep) with a dipping, elastic basal conveyor belt and a rigid backwall. An elastoplastic sand-rubber mixture (50 vol.% quartz sandG12: 50 vol.% EPDM rubber) is sieved into the setup representing a 240 km long forearc segment from the trench to the volcanic arc. The shallow part of the wedge includes a basal layer of sticky rice grains characterized by unstable stick-slip sliding representing the seismogenic zone. Stick-slip sliding in rice is governed by a rate-and-state dependent friction law similar to natural rocks. According to Coulomb wedge theory (Dahlen et al., 1984), two types of wedge configurations have been designed: a “compressional” configuration represents an interseismically compressional and coseismically stable wedge (compressional configuration), and a “critical” configuration, which is interseismically stable (close to critically compressional) and may reach a critical extensional state coseismically (critical configuration). In the compressional configuration, a flat-top (surface slope α=0) wedge overlies a single large rectangular in map view stick-slip patch (Width*Length=200*800 mm) over a 15-degree dipping basal thrust. In the critical configuration, the surface angle of the elastoplastic wedge varies from the coastal segment onshore (α=10) to the inner-wedge offshore (α=15) segments over a 5-degree dipping basal thrust. Slow continuous compression of the wedge by moving the basal conveyor belt at a speed velocity of 0.05 mm/s simulates plate convergence and results in the quasi-periodic nucleation of quasi-periodic stick-slip events (analog earthquakes) within the rice layer. The wedge responds elastically to these basal slip events, similar to crustal rebound during natural subduction megathrust earthquakes.

Description: This dataset provides friction data from ring-shear tests (RST) on twice broken rice used in the GEC Laboratory in CY Cergy Paris University in stick-slip experiments. They were obtained by Sarah Visage as part of her doctoral training (funded by the ANR DISRUPT programme) during an invitation at the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam. Like any granular material, the twice broken rice is characterized by several internal friction coefficients μ and cohesions C, classicaly qualified as dynamic, static, and reactivation coefficients. In adition, since the rice exhibits a stick slip behaviour, the various shear - velocity or shear-displacement curves exhibit high frequency oscillations and we therefore define maximum, minimum, and mean values corresponding respectively to the curve peaks, curve troughs and smoothed curve.

Description: This dataset provides friction data from ring-shear tests (RST) for wheat flour used as a fine-grained, cohesive analogue material for simulating brittle upper crustal rocks in the analogue labor-atory of the Institute of Geophysics of the Czech Academy of Science (IGCAS). It is characterized by means of internal friction coefficients µ and cohesion C. According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak friction coefficients µP of the tested material is ~0.72, dynamic friction coeffi-cients µD is ~0.67 and reactivation friction coefficients µR is ~0.70. Cohesions of the material range between 27 and 50 Pa. The material shows a minor rate-weakening of ~1.5% per ten-fold change in shear velocity v and a stick-slip behaviour at low shear velocities.

Description: As a supplement to Huang et al. (2022) “The influence of sediments, lithosphere and upper mantle (anelastic) with lateral heterogeneity on ocean tide loading and ocean tide dynamics”, we provide for the advanced earth model LH-Lyon-3Dae [consisting of 3D elastic sediments, lithosphere and 3D anelastic upper mantle structures, see Huang et al.(2022) for details] the solutions of vertical ocean tide loading (OTL) displacement, self-attraction and loading (SAL) elevation, and ocean tides. Solutions for three tidal constituents, i.e., M2, K1 and Mf, are given. As a comparison, solutions based on the 1D elastic model PREM and the 1D anelastic LH-Lyon-1Dae are also presented. With these solutions, the primary results in Huang et al. (2022) such as the model amplitude differences, RMS differences and the predictions in GNSS stations can be reconstructed.

Description: The Earth System Modelling Group of GeoForschungsZentrum Potsdam (ESMGFZ) provides geodetic products for gravity variations, Earth rotation excitations, and Earth surface deformations related to mass redistributions and mass loads in the atmosphere, ocean, and terrestrial water storage. Earth rotation excitation compiled as effective angular momentum (EAM) functions for each Earth subsystem (atmosphere, ocean, continental hydrology) are important for Earth rotation prediction. Especially the 6-day forecasts extending the model analysis runs offer essential information for the improvement of ultra-short-term Earth rotation predictions. In addition to the individual effective angular momentum function of each subsystem, ESMGFZ calculates a combined EAM prediction product. Adjusted to the official Earth orientation parameter (EOP) products IERS 14C04 and Bulletin A, this EAM prediction product allows to extrapolate the polar motion and Length-of-Day parameter time series for 90 days into the future via the Liouville equation. ESMGFZ submits such an EOP prediction to the 2nd EOPPCC campaign.

Description: Precise positioning and navigation on the Earth’s surface and in space require accurate earth orientation parameters (EOP) data and predictions. In the last few decades, EOP prediction has become a subject of increased attention within the international geodetic community, e.g., space agencies, satellite operators, researchers studying Earth rotation dynamics, and users of navigation systems. Due to this fact, many research centres from around the world have developed dedicated methods for the forecasting of EOP. An assessment of the various EOP prediction capabilities is currently being pursued in the frame of the Second Earth Orientation Parameters Prediction Comparison Campaign (2nd EOP PCC), which began in September 2021 and will be continued until the end of the year 2022. The new campaign was prepared by the EOP PCC Office run by Centrum Badań Kosmicznych Polskiej Akademii Nauk (CBK PAN) in Warsaw, Poland, in cooperation with GeoForschungsZentrum (GFZ) and under the auspices of the International Earth Rotation and Reference Systems Service (IERS). In this paper, we provide an overview of the 2nd EOP PCC five months after its start. We discuss the technical aspects and present statistics about the participants and valid prediction files received so far. Additionally, we present the results of preliminary comparisons of different reference solutions with respect to the official IERS 14 C04 EOP series. Root mean square values for different solutions for polar motion, length of day, and precession-nutation components show discrepancies at the level from 0.04 to 0.36 mas, from 0.01 to 0.10 ms, and from 0.01 to 0.18 mas, respectively.

Description: Previous studies have revealed that hydraulic fracturing behavior in crystalline rock (i.e., granite) is highly dependent on mineral content, grain size, and heterogeneity and is therefore quite different from the behavior observed in sedimentary rock (i.e., sandstone). We investigated hydraulic fracture paths generated via continuous and cyclic injections in Gonghe granite through uniaxial testing. Hydraulic fracturing breakdown pressure was reduced by 20% in cyclic injection. In particularly, we analyzed the role of biotite grains and pre-existing defects – such as natural fractures – in controlling hydraulic fracture propagation. We found that hydraulic fracture crossed natural fracture either without or with an offset in continuous injection, while hydraulic fracture was arrested by natural fracture in cyclic injection, and NF is more likely to be activated during high-cycle injection. This can be beneficial if hydro-shearing of pre-existing flaws is anticipated.

Description: The data set is a compilation of more than 300 CO2-rich mineral waters and mofettes in the NW Bohemia/Vogtland region. It is a combination of historical data from numerous books and reports, recent scientific papers, as well as own field observations. The oldest literature sources related to these geogenic CO2 gas emissions were mentioned in the 18th century. These springs were famous for their delicious acidic mineral water – so called “Sauerbrunnen” or "Säuerlinge". However, some gas emission sites and their springs dried and disappeared during the centuries, but they were an important meeting point in the villages (water supply) and were therefore mentioned in old geological or historical reports. The coordinates of these former locations could only be estimated. The dataset contains geographic coordinates, Czech and German site names, as well as the location type.

Description: This data repository contains the 3D steady-state thermal field computed for the South Caribbean and NW South America down to 75 km depth, the modelled hypocentral temperatures, the depths to the upper and lower stability transitions, as well as the seismogenic thickness calculated from selected earthquakes of the ISC Bulletin (International Seismological Centre, 2022). All methodological details can be found in the main publication (see section 2). We used the uppermost 75 km of the gravity-constrained structural and density model of Gómez-García et al. (2020, 2021) to derive the 3D thermal configuration of the study area. A steady-state approach was followed, in which upper and lower boundary conditions were set to run the thermal experiments using the software GOLEM (Cacace amp; Jacquey, 2017; Jacquey amp; Cacace, 2017). We selected earthquakes from the ISC Bulletin from January 1980 to January 2021 (International Seismological Centre, 2022), considering the magnitude of completeness for different periods, removing earthquakes without depth, set as 0 km or fixed, as well as those with reported hypocentral depth errors gt;30 km. Of this set, we selected the crustal earthquakes, located between the topo-bathymetry from the GEBCO relief (Weatherall et al., 2015) and the Moho depth from the GEMMA model (Reguzzoni amp; Sampietro, 2015), interpolated to a resolution of 5 km. From this earthquake subset we computed the upper and lower stability transitions for seismogenesis, as the 10th and 90th percentiles (D10 and D90), respectively, of the hypocentral depths. These percentiles were mapped on a latitude-longitude grid, using for each grid node its 20 closest earthquakes as sample. The hypocentral temperatures and the temperatures at the D10 and D90 crustal depths were calculated from the lithospheric-scale thermal model. Lastly, the crustal seismogenic thickness was computed as the difference between D90 and D10 for each grid node. For more details about the modelling approach and interpretation of the results, we kindly ask the reader to refer to the main publication: Gomez-Garcia et al., (2022).

Description: Stress maps show the orientation of the current maximum horizontal stress (SHmax) in the earth's crust. Assuming that the vertical stress (SV) is a principal stress, SHmax defines the orientation of the 3D stress tensor; the minimum horizontal stress Shmin is than perpendicular to SHmax. In stress maps SHmax orientations are represented as lines of different lengths. The length of the line is a measure of the quality of data and the symbol shows the stress indicator and the color the stress regime. The stress data are freely available and part of the World Stress Map (WSM) project. For more information about the data and criteria of data analysis and quality mapping are plotted along the WSM website at http://www.world-stress-map.org. The stress map of Taiwan 2022 is based on the WSM database release 2016. However, all data records have been checked and we added a large number of new data from earthquake focal mechanisms from the national earthquake catalog and from publications. The total number of data records has increased from n=401 in the WSM 2016 to n=6,498 (4,234 with A-C quality) in the stress map of Taiwan 2022 The update with earthquake focal mechanims is even larger since another 1313 earthquake focal mechanism data records beyond the scale of this map have been added to the WSM database. The digital version of the stress map is a layered pdf file generated with GMT (Wessel et al., 2019). It also provide estimates of the mean SHmax orientation on a regular 0.1° grid using the tool stress2grid (Ziegler and Heidbach, 2019). Two mean SHmax orientations are estimated with search radii of r=25 and 50 km, respectively, and with weights according to distance and data quality. The stress map and data are available on the landing page at https://doi.org/10.5880/WSM.Taiwan2022 where further information is provided. The earthquake focal mechanism that are used for this stress map are provided by the Taiwan Earthquake Research Center (TEC) available at the TEC Data Center (https://tec.earth.sinica.edu.tw).

Description: This dataset provides information about the hydrostatic and wet signal delays from a network of 23 GNSS stations in northwestern Argentina between 2010-2021. It is based on Global Navigation Satellite System (GNSS) remote sensing techniques for the estimation of the atmospheric total delay and its gradients. Additionally, the hydrostatic counterpart and its gradients were calculated from the ERA5 dataset of the European Centre for Medium-Range Weather Forecasts (ECMWF) with ray-tracing algorithms. The wet delays, as well as their gradients, were calculated by subtracting the hydrostatic fraction from the total proportion. Lastly, the wet signal delays were also computed using solely the ERA5 dataset.

Description: For the first time, rain effects on the polarimetric observations of the global navigation satellite system reflectometry (GNSS-R) are investigated. The physical feasibility of tracking the modifications in the surface roughness by rain splash and the surface salinity by the accumulation of freshwater is theoretically discussed. An empirical analysis is carried out using measurements of a coastal GNSS-R station with two side-looking antennas in right- and left-handed circular polarizations (RHCP and LHCP). Discernible drops in RHCP and LHCP powers are observed during rain over a calm sea. The power drop becomes larger at higher elevation angles. The average LHCP power drops by ≈ 5 dB at an elevation angle of 45°. The amplitude of the correlation sum shows a dampening, responding to rain rate systematically. The LHCP observations show higher sensitivity to rainfall compared to RHCP observations. The retrieved standard deviation of surface heights shows a steady increase with the rain rate. The derived surface salinity shows a decrease at rains higher than 10 mm/h. This study confirms the potential under environmental conditions of the GNSS-R ground-based station, e.g., with salinity mostly lower than 30 psu, over a calm sea, being a starting point for future investigations.

Description: This dataset comprises the PCEEJ equatorial electrojet model current intensity values (mA/m). The PCEEJ is an empirical model based on the principal component analysis of satellite and ground equatorial electrojet data, described in detail in Soares et al. (2022), to which this data publication is supplement to. The model data is provided as text files (.csv extension) and Matlab-formatted files (.mat extension). For text files, there is one file per year (file name labeled with the corresponding year). For the Matlab format, there is only one Matlab file that contains all years as separate variables (variable name labeled with the corresponding year). Each yearly file/variable corresponds to a matrix: the rows represent local time/longitude bins and the columns represent days of year. The local time/longitude bins (rows) always sum up to 432 (12 local time intervals and 36 longitude intervals). The day of year (columns) always starts in January 1st and ends in December 31st, leading to a total of 365 or 366. The PCEEJ model values of 13 years from 2003 to 2010 and from 2014 to 2018 are provided. The PCEEJ basis functions (principal components) are provided in the text and Matlab files labeled as ‘PC\_Functions’. The ‘PC\_Functions’ data is given as a 432x10 matrix, in which 432 stands for the aforementioned local time/longitude bins and 10 represents the 10 principal components used to obtain the PCEEJ model (in ascending order). Two additional auxiliary indices, namely ‘lt\_index’ and ‘lon\_index’ are also contained as text and Matlab files. These indices represent the corresponding local time and longitude values of each row of the PCEEJ yearly files and ‘PC\_Functions’ files.

Description: Storm sudden commencements (SSC) often precede geomagnetic storms. Commonly, it takes some hours from the step-like change that marks the SSC to the start of the magnetic storm activity. In a subset of cases, however, auroral activity starts almost instantaneously after the SSC. To the authors knowledge, the conditions that enable this rapid activation have not been investigated in detail before. Here we consider all the sudden commencements (SC) during the years 2000–2020. Our focus is on the initial response of the auroral currents on the nightside. For that purpose, we make use of the IMAGE Magnetometer Network in Fennoscandia. In about 30% of SC events an initial activation of the westward electrojet is observed. Magnetic deflections of the northward component, surpassing frequently 1,000 nT, are observed only 4 min after the SC. These intense westward currents, flowing typically in narrow channels of 1°–2° latitudinal width, last some 10 min. The electrojets are conjugate to regions in the magnetosphere near geostationary orbits. In several cases geomagnetic substorm onsets are observed about 30 min after the SC. These start typically at fairly high latitude, around 71° magnetic latitude. This is an indication for rather quiet conditions preceding the onset. The magnetic pulse of the SC seems to play an important role in initiating the strong electrojets and the substorms. These initial activities are of relevance for space weather effects because of their strong and rapid variations. This paper provides detailed observations of the initial auroral activity following some SCs.

Description: Ionospheric currents have widely been investigated by using magnetic measurements from low-Earth orbiting satellites. However, the assumptions of deriving currents from the magnetic measurements have not always been well considered. In this study we performed a detailed analysis of the ionospheric radial current (IRC) and inter-hemispheric field-aligned current (IHFAC) estimates at equatorial and low latitudes derived from the single-satellite and dual-spacecraft (dual-SC) approaches of European Space Agency (ESA's) Swarm constellation. Data considered cover a 5-year period, from 17 April 2014 to 16 April 2019. We found for most of the cases, the IRCs and IHFACs derived from both approaches show consistent latitudinal profiles. However, there are several cases with discrepancy exceeding 5 nA/m2 between two approaches. On average, the diurnal variations of IHFACs from both approaches agree well with each other for all seasons. But the amplitudes of single-satellite results reach only about 70% of those from the dual-SC. This difference is attributed to the fact that only the magnetic field By component is utilized in the single-satellite approach, while both Bx and By components are considered in the dual-SC approach. Above the magnetic equator, the IRCs derived from single-satellite approach show clear tidal signatures, while such signature cannot be found in the IRCs from dual-SC approach. We interpret these tidal-signature of IRCs as spurious results, caused by equatorial electrojet contributions to the ∆By component. The dual-SC derived IRCs show notable differences between ascending and descending orbits. Such differences might be due to a violation of the assumed perfect calibration of Swarm A and C. We suggest a systematic spacecraft-fixed bias in the along-track magnetic field component (Bx) between Swarm A and C. By interpreting the IRC differences, we obtain bias values of ∆Bx reaching 1 nT. Our results reveal that ionospheric currents are better characterized by the dual-SC approach. But comparison with single-satellite current estimates can help to identify weakness.

Description: Despite the importance of surface energy budgets (SEBs) for land-climate interactions in the Arctic, uncertainties in their prediction persist. In situ observational data of SEB components - useful for research and model validation - are collected at relatively few sites across the terrestrial Arctic, and not all available datasets are readily interoperable. Furthermore, the terrestrial Arctic consists of a diversity of vegetation types, which are generally not well represented in land surface schemes of current Earth system models. This dataset describes the data generated in a literature synthesis, covering 358 study sites on vegetation or glacier (〉=60°N latitude), which contained surface energy budget observations. The literature synthesis comprised 148 publications searched on the ISI Web of Science Core Collection.

Description: Strain NGK35T is a motile, Gram-stain- negative,rod-shaped (1.0–2.1 μm long and 0.6–0.8 μm wide), aerobic bacterium that was isolated from plastic-polluted landfill soil. The strain grew at temperatures between 6 and 37 °C (optimum, 28 °C), in 0–10 % NaCl (optimum, 1 %) and at pH 6.0–9.5 (optimum, pH 7.5–8.5). It was positive for cytochrome c oxidase, catalase as well as H2S production, and hydrolysed casein and urea. It used a variety of different carbon sources including citrate, lactate and pyruvate. The predominant membrane fatty acids were C16 : 1 cis9 and C16 : 0, followed by C17 : 0 cyclo and C18 : 1 cis11. The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine, followed by diphosphatidyglycerol. The only quinone was ubiquinone Q-8. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NGK35T belongs to the genus Paenalcaligenes (family Alcaligenaceae), appearing most closely related to Paenalcaligenes hominis CCUG 53761AT (96.90 %) and Paenalcaligenes suwonensis ABC02-12T (96.94 %). The genomic DNA G+C content of strain NGK35T was 52.1 mol %. Genome-based calculations (genome-to-genome distance, average nucleotide identity and DNA G+C content) clearly indicated that the isolate represents a novel species within the genus Paenalcaligenes. Based on phenotypic and molecular characterization, strain NGK35T can clearly be differentiated from its phylogenetic neighbours establishing a novel species, for which the name Paenalcaligenes niemegkensis sp. nov. is proposed. The type strain is NGK35T (=DSM 113270T=NCCB 100854T).

Description: The intensity of the equatorial electrojet (EEJ) shows temporal and spatial variability that is not yet fully understood nor accurately modeled. Atmospheric solar tides are among the main drivers of this variability but determining different tidal components and their respective time series is challenging. It requires good temporal and spatial coverage with observations, which, previously could only be achieved by accumulating data over many years. Here, we propose a new technique for modeling the EEJ based on principal component analysis (PCA) of a hybrid ground-satellite geomagnetic data set. The proposed PCA-based model (PCEEJ) represents the observed EEJ better than the climatological EEJM-2 model, especially when there is good local-time separation among the satellites involved. The amplitudes of various solar tidal modes are determined from PCEEJ based tidal equation fitting. This allows to evaluate inter- and intra-annual changes of solar tidal signatures in the EEJ. On average, the obtained time series of migrating and non-migrating tides agree with the average climatology available from earlier work. A comparison of tidal signatures in the EEJ with tides derived from neutral atmosphere temperature observations show a remarkable correlation for non-migrating tides such as DE3, DE2, DE4 and SW4. The results indicate that it is possible to obtain a meaningful EEJ spectrum related to solar tides for a relatively short time interval of 70 days.

Description: This data publication includes the half-hourly Hp30 and ap30 indices as well as the hourly Hp60 and ap60 indices, collectively denoted as Hpo. This dataset is based on near real-time geomagnetic observatory data provided by 13 contributing observatories. It is derived and distributed by GFZ German Research Centre for Geosciences. When using the Hpo index, please cite this data publication as well as the accompanying publication Yamazaki et al. (submitted), which serves as documentation of the Hpo. The dataset is organised in yearly files, which, for the current year, are updated on a monthly basis. Typically, during the second week of a month, the data for the previous month is appended to the current year's file. The files are in ASCII files and start with header lines marked with # (hash). The Hpo index was developed within the H2020 project SWAMI (grant agreement No 776287) and is produced by Geomagnetic Observatory Niemegk, GFZ German Research Centre for Geosciences. It derives from the same 13 geomagnetic observatories that also contribute to the Kp index (Matzka et al., 2021, https://doi.org/10.5880/Kp.0001). They are listed as contributors to this data publication. With the introduction of the DOI for the Hpo index (Matzka et al, 2021, https://doi.org/10.5880/Hpo.0001), this DOI landing page and the associated HTTPS server linked to the DOI become the primary archive of Hpo (while the other established index distribution mechanisms at GFZ will be maintained in parallel). With the DOI, the dataset can grow with time, but a change of the data, once published, is not possible. If necessity arises in the future to correct already published values, then the corrected dataset will be published with a new DOI. Older DOIs and data sets will then still be available. For each DOI, an additional versioning mechanism will be available to document changes to the files such as header or format changes, which do not affect the integrity of the data. The DOI https://doi.org/10.5880/Hpo.0002 identifies the current version. A format description and a version history are provided in the data download folder.

Description: The Flood Similarity Workflow is part of the Flood Event Explorer (FEE, Eggert et al., 2022), developed at the GFZ German Research Centre for Geosciences . It is funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project (https://www.digitalearth-hgf.de/). River floods and associated adverse consequences are caused by complex interactions of hydro-meteorological and socio-economic pre-conditions and event characteristics. The Flood Similarity Workflow supports the identification, assessment and comparison of hydro-meteorological controls of flood events. The analysis of flood events requires the exploration of discharge time series data for hundreds of gauging stations and their auxiliary data. Data availability and accessibility and standard processing techniques are common challenges in that application and addressed by this workflow. The Flood Similarity Workflow allows the assessment and comparison of arbitrary flood events. The workflow includes around 500 gauging stations in Germany comprising discharge data and the associated extreme value statistics as well as precipitation and soil moisture data. This provides the basis to identify and compare flood events based on antecedent catchment conditions, catchment precipitation, discharge hydrographs, and inundation maps. The workflow also enables the analysis of multidimensional flood characteristics including aggregated indicators (in space and time), spatial patterns and time series signatures. The added value of the Flood Event Explorer comprises two major points. First, scientist work on a common, homogenized database of flood events and their hydro-meteorological controls for a large spatial and temporal domain , with fast and standardized interfaces to access the data. Second, the standardized computation of common flood indicators allows a consistent comparison and exploration of flood events.

Description: We present a dataset of in-situ measurements in the marginal area of a CO2- and brine-rich cavernous structure in an underground salt mine. The data were collected within the framework of the BMBF-project ProSalz. One aim was to reveal the sources and dynamics of fluid movement as well as temporal and spatial distribution of fluids in a potentially weakened cavern rim. Over a period of three years pressure and gas monitoring was carried out along a transect from a cavernous structure to undisturbed rock salt. In addition, temperature and relative humidity data from the underground gallery were recorded. The gas inflow into isolated borehole sections provided an insight into short- and long-term changes of gas migration patterns in rock salt. Pressure increases of up to 4kPa/day and CO2 concentrations of up to 1.2%, especially at the start of the campaign were measured. The gas migration is coupled to discrete fractures and was limited spatially and temporary. Overall, gas occurrences were not correlated to their distance to the cavern, suggesting no wide-ranging fluid-rock interaction within the rim of the investigated natural cavernous structure in rock salt.

Description: The dataset comprises a range of variables describing characteristics of flood events and river catchments for 480 gauging stations in Germany and Austria. The event characteristics are asscoiated with annual maximum flood events in the period from 1951 to 2010. They include variables on event precipitation, antecedent catchment state, event catchment response, event timing, and event types. The catchment characteristics include variables on catchment area, catchment wetness, tail heaviness of rainfall, nonlinearity of catchment response, and synchronicity of precipitation and catchment state. The variables were compiled as potential predictors of heavy tail behaviour of flood peak distributions. They are based on gauge observations of discharge, E-OBS meteorological data (Haylock et al. 2008), mHM hydrological model simulations (Samaniego et al., 2010), 4DAS climate reanalysis data (Primo et al., 2019), and the 25x25 m resolution EU-DEM v1.1. A short description of the data processing is included in the file inventory and more details can be found in Macdonald et al. (2022).

Description: This dataset provides Rapid Science Orbits (RSO) from the Low Earth Orbiter (LEO) satellite GRACE-FO-1. 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-FO RSO cover the period: - from 2019 049 to up-to-date The LEO RSOs in version 2 are generated based on the 30-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. Due to the extended length of the constellation, there is no need to concatenate several constellations for day-overlapping arcs. The accuracy of the LEO RSOs is at the level of 1-2 cm in terms of SLR validation. Each solution in version 2 is given in the Conventional Terrestrial Reference System (CTS) based on the IERS 2010 conventions and related to the ITRF-2014 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: floodsimilarity provides classes and methods to conduct a similarity analysis between multiple flood events. The library mainly consists of two parts: (1) algorithms to compute indices and other statistics based on pandas and xarray (2) well-defined data structures for data exchange (e.g. through the Similarity Backend Module) floodsimilarity is used by the Digital Earth Similarity Backend Module (Eggert, 2021) as part of the Digital Earth Flood Event Explorer. It is developed at the GFZ German Research Centre for Geosciences and funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project.

Description: The Smart Monitoring Workflow (Tocap) is part of the Flood Event Explorer (FEE, Eggert et al., 2022), developed at the GFZ German Research Centre for Geosciences in close collaboration with the Helmholtz-Centre for Environmental Research UFZ Leipzig. It is funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project (https://www.digitalearth-hgf.de/). A deeper understanding of the Earth system as a whole and its interacting sub-systems depends not only on accurate mathematical approximations of the physical processes but also on the availability of environmental data across time and spatial scales. Even though advanced numerical simulations and satellite-based remote sensing in conjunction with sophisticated algorithms such as machine learning tools can provide 4D environmental datasets, local and mesoscale measurements continue to be the backbone in many disciplines such as hydrology. Considering the limitations of human and technical resources, monitoring strategies for these types of measurements should be well designed to increase the information gain provided. One helpful set of tools to address these tasks are data exploration frameworks providing qualified data from different sources and tailoring available computational and visual methods to explore and analyse multi-parameter datasets. In this context, we developed a Smart Monitoring Workflow to determine the most suitable time and location for event-driven, ad-hoc monitoring in hydrology using soil moisture measurements as our target variable. The Smart Monitoring Workflow consists of three main steps. First is the identification of the region of interest, either via user selection or recommendation based on spatial environmental parameters provided by the user. Statistical filters and different color schemes can be applied to highlight different regions. The second step is accessing time-dependent environmental parameters (e.g., rainfall and soil moisture estimates of the recent past, weather predictions from numerical weather models and swath forecasts from Earth observation satellites) for the region of interest and visualizing the results. Lastly, a detailed assessment of the region of interest is conducted by applying filter and weight functions in combination with multiple linear regressions on selected input parameters. Depending on the measurement objective (e.g highest/lowest values, highest/lowest change), most suitable areas for monitoring will subsequently be visually highlighted. In combination with the provided background map, an efficient route for monitoring can be planned directly in the exploration environment. The added value of the Smart Monitoring Workflow is multifold. The workflow gives the user a set of tools to visualize and process their data on a background map and in combination with data from public environmental datasets. For raster data from public databases, tailor-made routines are provided to access the data in the spatial-temporal limits required by the user. Aiming to facilitate the design of terrestrial monitoring campaigns, the platform and device-independent approach of the workflow gives the user the flexibility to design a campaign at the desktop computer first and to refine it later in the field using mobile devices. In this context, the ability of the workflow to plot time-series of forecast data for the region of interest empowers the user to react quickly to changing conditions, e.g thunderstorm showers, by adapting the monitoring strategy, if necessary. Finally, the integrated routing algorithm assists to calculate the duration of a planned campaign as well as the optimal driving route between often scattered monitoring locations.

Description: This data publication presents global high-frequency mass variability that is induced by individual oceanic and atmospheric partial tides. While the atmospheric component is obtained by conducting a tidal analysis of numerical weather data data, the oceanic component has been produced using the hydro-dynamical ocean tide model TiME that was recently upgraded in the framework of the DFG-funded Research Group NEROGRAV ( https://www.lrg.tum.de/iapg/nerograv/) and can be used for gravimetric applications. The overall goal of this project is to facilitate the analysis of gravimetric data sets (e.g. GRACE/GRACE-FO) by improving the understanding of sensor data, processing strategies, and background models. The data set presented herein contributes to this goal as the here described tidally induced mass variations are an important part of the described background models. As tidal variability is usually described as a superposition of so-called partial tides, the presented mass variations can be attributed to individual partial tide frequencies and are thus represented by individual files for each partial tide frequencies. Here, not only the effect of direct gravitation exerted by the ocean and atmospheric mass is included but also gravity variations due to the elastic yielding of the solid Earth in response to water and atmospheric mass redistribution (the load tide) are allowed for. The information describing the partial tides has been transformed to fully normalized Stokes Coefficients describing harmonic in-phase and quadrature component fields as those are especially handy for gravimetric purposes. Additionally, a set of files that allows further expansion of the ensemble of ocean partial tides via linear admittance theory is provided.

Description: This dataset provides Rapid Science Orbits (RSO) from the Low Earth Orbiter (LEO) satellite TerraSAR-X. 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 TerraSAR-X RSO cover the period - from 2007 264 to up-to-date 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: Organic matter (OM) is known to be an important reductant in sediment-hosted base metal deposits like the European Kupferschiefer. However, the precise nature of interactions between OM and hydrothermal fluids are still debated as well as how the interconnected reactions develop over geological timescales. This dataset provides for the first time bulk, compositional and stable isotope data of hydrocarbons, biomarkers and organonitrogen, -sulfur and-oxygen (NSO) compounds for the mineralized Kupferschiefer Spremberg-Graustein field in Eastern Germany based on samples from two drill cores. The study aims to help to better understand the role that organic matter plays during the mineralisation and formation of the sedimentary ore deposit within the Kupferschiefer with a focus on stable hydrogen isotope compositions and NSO compositional data to especially address the origin and to assess the oxidative nature of the brines that caused the mineralization in the Spremberg-Graustein field. The data publication includes bulk, compositional and stable isotope data on inorganic metals and organic matter. The data about metal contents were generated using ICP-MS while those on the organic matter were generated using Rock-Eval pyrolysis, a microscope, a Soxhlet apparatus, medium pressure liquid chromatography (MPLC), gas chromatography with flame ionization (GC-FID) and mass spectrometric detection (GC-MS), gas chromatography isotope ratio mass spectrometry (GC-IRMS) and ultrahigh resolution mass spectrometry (Fourier Transform ion cyclotron resonance mass spectrometry, FT-ICR-MS) with Electrospray ionization (ESI) and Atmospheric pressure photoionization (APPI). The full description of samples, methods and data is given in the following sections.

Description: Carbon is an element that controls planetary habitability, and is fundamental for life on Earth. Its behaviour has important consequences for the global climate system, the origin and evolution of life on Earth. While the biosphere and atmosphere’s carbon cycle only accounts for less than 1% of the global carbon budget, hidden reservoirs of deep carbon in the Earth’s interior comprise the predominant storage of carbon on the planet. At the Earth’s surface, 60-70 % of carbon is hosted by carbonate minerals, which are then transported to the Earth’s interior, mainly in the form of sediments, by subduction of the oceanic lithosphere. Subducting plates are subjected to decarbonation, dehydration, and melting with CO2 release via supra-subduction volcanism. Nevertheless, part of the subducted carbonates’ may survive and be further transported to the deep mantle. Direct evidence of the existence of carbonates in the Earth’s interior, possibly reaching down to the lower mantle, comes from the finding of syngenetic inclusions of carbonates in diamonds and mantle xenoliths. The presence of carbonates in the deep Earth has a critical effect on the physical properties of the mantle. Melting and chemical speciation of the mantle are strongly affected by the form of C and carbonate stability. Therefore, the study of the stability and physical properties of carbonates at high pressures and temperatures is fundamental, because understanding the processes involved in the deep carbon cycle helps to improve our picture of the whole mantle. The systematic characterization of the elastic properties of carbonates as a function of their structure and chemical composition is of great importance because it may allow to identify their presence and distribution by seismology. Inverting seismic observations to successfully constrain the chemical composition and mineralogy of the Earth’s interior requires knowledge of the physical properties of all possible Earth’s materials at pressures and temperatures applicable to the Earth’s interior. Up to now, a multitude of studies has focused on the construction of phase diagrams and structural transitions by means of X-ray diffraction and vibrational spectroscopy experiments. Few studies are available on the complete elastic tensor of carbonates, however most of the datasets are not accompanied by an accurate characterization of the samples, which are often solid solutions and the exact chemical composition, density or the details about the experimental methods used are not presented. The aim of this thesis is to study the effect of chemical composition on the elastic properties of carbonates, providing a reliable dataset on the elasticity of the main carbonates. In particular, the elastic properties of crystalline aragonite, CaCO3, and Fe-dolomite, (Ca, Mg, Fe)(CO3)2, with different compositions were studied by Brillouin spectroscopy at ambient conditions. Brillouin spectroscopy was also used to investigate the elastic behaviour of amorphous calcium carbonate samples with different water contents (up to 18 wt%) at high pressures, up to 20 GPa. Furthermore, the importance of cationic substitution on the structure and high pressure behaviour of carbonates was investigated by studying a synthetic CaCO3-SrCO3 solid solution at ambient conditions and at high pressures, up to 10 GPa, by single crystal X-ray diffraction. Finally, the study of the effect of composition on the elastic properties of families of isostructural solids was also extended to a different class of materials, the metal guanidinium formates. The elasticity of a family of perovskite metal organic frameworks, metal guanidinium formates C(NH2)3MII(HCOO)3, with MII =Mn, Zn, Cu, Co, Cd and Ca was investigated by combining Brillouin spectroscopy, resonant ultrasound spectroscopy, density functional theory and thermal diffuse scattering analysis.

Description: This dataset includes surface 3D stereoscopic Digital Image Correlation (3D stereo DIC) images and videos of 10 analogue models on crustal scale rifting with a rotational component. In addition, this dataset provides CT imagery of four analogue models that have been analyzed by means of Digital Volume Correlation (DVC) applied on X-Ray computed tomography volumes. Data of CT scanned models also includes slices of the volumetric displacement set for each displacement component. Using a brittle-viscous two-layer setup, the experiments focused on surface rift propagation, internal viscous flow driven by a horizontal pressure gradient and the interaction of internal and surface deformation. All experiments were performed at the Tectonic Modelling Laboratory of the University of Bern (UB). 3D stereo DIC analyses were performed at the GFZ German Research Centre for Geosciences (GFZ) and DVC analyses were performed at the Royal Holloway University London (RHUL). All models consist of a two-layer brittle-viscous set up with a total thickness of 6 cm. Thickness variations in brittle and ductile layers are expressed by the ratio RBD = brittle layer thickness/ductile layer thickness, which ranges from RBD = 0.5 to RBD = 2. The model set up lies on top of a 5 cm thick foam base with a trapezoidal shape with a height of 900 mm and a pair of bases with widths of 310 mm and 350 mm at the far ends, respectively. The foam block is sliced into segments such that 7 interlayered 0.5 cm thick plexiglass bars prevent foam collapse under the model weight. Before model construction, the foam-plexiglass assemblage is placed between longitudinal side walls. The experimental set-up is such that rotational extension in one part of the model domain is separated from rotational shortening in the other part of the model domain by a vertical rotation axis (Fig. 1). During the model run, the foam homogeneously expands in the domain undergoing extension and homogeneously contracts in the domain undergoing shortening. The applied velocity for all models is 10 mm/h and refers to the divergence of the sidewalls furthest away from the rotation axis which decreases linearly towards the rotation axis. This results in a maximum displacement of 40 mm at the outermost circular segment after a total run time of 4h.

Description: The dataset presented in this compilation provides the input data used for the geological interpretation and for the model parameterization (Norden et al., 2022) of a 3D seismic survey in the area of the geothermal research platform Groß Schönebeck (carried out in 2017; Krawczyk et al., 2019), focussing on the deep Permo-Carboniferous geothermal targets. The geothermal research platform Groß Schönebeck is located about 50 km north of Berlin, on the southern edge of the Northeast German Basin, and is equipped with two deep wells, the E GrSk 3/90 and Gt GrSk 4/05 boreholes. In this data compilation we provide general data on the location of the boreholes and data on the applied methods and the interpretation of petrophysical properties (density, porosity, permeability, thermal properties) obtained by core analysis and well-log interpretation. Because cores were available for the E GrSk 3/90 borehole only, most of the data is referring to the borehole that was drilled more or less vertically. The other borehole (Gt GrSk 4/05) is a deviated well, drilled as a geothermal production well. Further on, we provide the main interpreted structural reflector horizons of the geological model from surface to the assumed top of sedimentary Carboniferous (for discussion of the uncertainty of this boundary please consider the comments in Norden et al., 2022) and the horizons and 3D grid properties of a parameterized simulation grid for the deep geothermal target (sedimentary Rotliegend and Permo-Carboniferous volcanic rocks).

Description: The dataset presented here is an enhanced earthquake catalog for the northern Armutlu Peninsula (northwestern Turkey) constructed by matched-filter search in EQcorrscan (Chamberlain et al., 2018) on continuous daily waveforms. The enhanced catalog is constructed using template events from the STA/LTA relocated catalog of Martínez-Garzón et al. (2022, https://doi.org/10.5880/GFZ.4.2.2021.004). It is built using waveforms and phase arrivals from up to 30 stations of the SMARTnet temporary seismic network, two stations of the GONAF borehole permanent network, and three stations of the KOERI permanent network for channels that contain data for at least the 80% of the day. The magnitudes of the new detections are calculated by relative amplitude difference with the respective template. The magnitude of completeness of this catalog is Mw = 0.8. The catalog spans the time period from 25 January 2019 to 07 February 2020. Direct evidence of a slow-slip transient modulating the spatiotemporal and frequency-magnitude earthquake distribution: insights from the Armutlu Peninsula, northwestern Turkey" by Bocchini et al. (2022). The dataset consists of two files: (1) “enhanced\_catalog\_absolute\_locations.csv” that contains 7,677 seismic events (templates and new detections) for which we could successfully calculate an earthquake location; and (2) “enhanced\_catalog\_relocated.csv” that contains 4,128 seismic events for which we could refine the initial location and obtain a double-difference refined location.

Description: Starting in 2016, the Taroko Earth Surface Observatory (TESO), a catchment-wide geomorphic observatory was set up in the Liwu catchment in the Taroko National Park in Taiwan. The set up consists of two basic station types: combined seismic and weather stations, featuring a broadband seismometer logging and a multi-parameter weather sensor, and hydrometric stations, the instrumentation of which are specific at each location. Seismic data hosted by the GEOFON database is openly accessible in real time.

Description: The Digital Earth Flood Event Explorer supports geoscientists and experts to analyse flood events along the process cascade event generation, evolution and impact across atmospheric, terrestrial, and marine disciplines. It applies the concept of scientific workflows and the component-based Data Analytics Software Framework (DASF, Eggert and Dransch, 2021) to an exemplary showcase. It aims at answering the following geoscientific questions: - How does precipitation change over the course of the 21st century under different climate scenarios over a certain region? - What are the main hydro-meteorological controls of a specific flood event? - What are useful indicators to assess socio-economic flood impacts? - How do flood events impact the marine environment? - What are the best monitoring sites for upcoming flood events? The Flood Event Explorer developed scientific workflows for each geoscientific question providing enhanced analysis methods from statistics, machine learning, and visual data exploration that are implemented in different languages and software environments, and that access data form a variety of distributed databases. The collaborating scientists are from different Helmholtz research centers and belong to different scientific fields such as hydrology, climate-, marine-, and environmental science, and computer- and data science. It is funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project (https://www.digitalearth-hgf.de/).

Description: This data set includes data derived from high-speed surface displacement observations from analog earthquake experiments. The data consists of surface displacement of the experiment upper plate and slab, slip distribution, and grids of Coulomb Failure Stress (CFS). The surface displacement observations have been captured using a highspeed CMOS (Complementary Metal Oxide Semiconductor) camera (Phantom VEO 640L camera, 12 bit) and processed with LaVision Davis 10 software. Description of the experiments and results regarding the surface displacement observation, Slip distribution, and CFS can be found in Kosari et al. (2022), to which this data set is supplementary. We use an analog seismotectonic scale model approach (Rosenau et al., 2019 and 2017) to generate a catalog of analog megathrust earthquakes. The presented experimental setup is modified from the 3D setup used in Rosenau et al. (2019) and Kosari et al. ( 2020 and 2022). The subduction forearc model wedge is set up in a glass-sided box (1000 mm across strike, 800mm along strike, and 300 mm deep) with a dipping, elastic basal conveyor belt, and a rigid backwall. An elastoplastic sand-rubber mixture (50 vol.% quartz sandG12: 50 vol.% EPDM rubber) is sieved into the setup representing a 240 km long forearc segment from the trench to the volcanic arc. The shallow part of the wedge includes a basal layer of sticky rice grains characterized by unstable stick-slip sliding representing the seismogenic zone. The Stick-slip sliding in rice is governed by a rate-and-state dependent friction law similar to natural rocks. A flat-top (surface slope α=0) wedge overlies rectangular stick-slip patch/es over a 15-degree dipping basal thrust. Two different seismic configurations of the shallow part of the wedge base (the megathrust) represent the depth extent of the seismogenic zone in nature. In the first configuration (homogeneous configuration), a single large rectangular stick-slip patch (Width*Length=200*800 mm) is implemented as the main slip patch (MSP). In the second case (heterogeneous configuration), two square-shaped MSPs (200*200mm) have been emplaced, acting as two medium-size seismogenic asperities surrounded by a salt matrix hosting frequent small events. Slow continuous compression of the wedge by moving the basal conveyor belt at a speed velocity of 0.05 mm/s simulates plate convergence and results in the quasi-periodic nucleation of quasi-periodic stick-slip events (analog earthquakes) within the sticky-rice layer. The wedge responds elastically to these basal slip events, similar to crustal rebound during natural subduction megathrust earthquakes.

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 (this DOI) - GRACE-B from 2004 200 to 2017 245 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: This data publication presents data from a solaroptical spectral investigation in the area of the Rammelsberg non-ferrous metal mine in the Harz Mountains near the city of Goslar. The investigation refers to the local communion stone quarry (“Kommunionssteinbruch”) above the former mining area. As this is a nature conservation zone, all measurements were carried out in-situ without any physical sampling action. The field measurements were carried out in June 2019 in cooperation with Bergbau Goslar GmbH and the German Research Centre for Geosciences (GFZ). The data were collected within the research project ReMon (Remote Monitoring of Tailings Using Satellites and Drones, https://www.gfz-potsdam.de/en/section/remote-sensing-and-geoinformatics/projects/remon/) which aims at developing a prototypical monitoring system for mine tailings by using different sensors scaling from satellite- to drone-based. The data were analysed in the unpublished B.Sc. thesis of Constantin Hildebrand (Hildebrand, 2019). Sixteen different surface materials were determined and examined on-site. Point and imaging hyperspectral data were acquired (with the spectroradiometer PSR+ 3500 operating in the range of 350 - 2500 nm and with the Cubert FireflEYEUHD-185 hyperspectral camera with a range of 450 - 950 nm, respectively), both data sets are presented as spectral libraries. Chemical analyses of the samples were performed by using Laser-Induced Breakdown Spectroscopy (LIBS). LIBS data were collected using a handheld LIBS analyzer, the SciAps Z-300. In this data publication the different in-situ measurements are presented for each of the sixteen samples. Detailed information about the analysed material, the area of spectral sampling and geochemical analyses are explained in this report and can also be found in the additional Excel® sheet provided with the data.

Description: The success of scientific projects increasingly depends on using data analysis tools and data in distributed IT infrastructures. Scientists need to use appropriate data analysis tools and data, extract patterns from data using appropriate computational resources, and interpret the extracted patterns. Data analysis tools and data reside on different machines because the volume of the data often demands specific resources for their storage and processing, and data analysis tools usually require specific computational resources and run-time environments. The data analytics software framework DASF, developed at the GFZ German Research Centre for Geosciences (https://www.gfz-potsdam.de) and funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project (https://www.digitalearth-hgf.de/), provides a framework for scientists to conduct data analysis in distributed environments. The data analytics software framework DASF supports scientists to conduct data analysis in distributed IT infrastructures by sharing data analysis tools and data. For this purpose, DASF defines a remote procedure call (RPC) messaging protocol that uses a central message broker instance. Scientists can augment their tools and data with this protocol to share them with others. DASF supports many programming languages and platforms since the implementation of the protocol uses WebSockets. It provides two ready-to-use language bindings for the messaging protocol, one for Python and one for the Typescript programming language. In order to share a python method or class, users add an annotation in front of it. In addition, users need to specify the connection parameters of the message broker. The central message broker approach allows the method and the client calling the method to actively establish a connection, which enables using methods deployed behind firewalls. DASF uses Apache Pulsar (https://pulsar.apache.org/) as its underlying message broker. The Typescript bindings are primarily used in conjunction with web frontend components, which are also included in the DASF-Web library. They are designed to attach directly to the data returned by the exposed RPC methods. This supports the development of highly exploratory data analysis tools. DASF also provides a progress reporting API that enables users to monitor long-running remote procedure calls. One application using the framework is the Digital Earth Flood Event Explorer (https://git.geomar.de/digital-earth/flood-event-explorer). The Digital Earth Flood Event Explorer integrates several exploratory data analysis tools and remote procedures deployed at various Helmholtz centers across Germany.

Description: This dataset provides Rapid Science Orbits (RSO) from the Low Earth Orbiter (LEO) satellite TerraSAR-X. 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 TerraSAR-X RSO cover the period - from 2007 264 to up-to-date The LEO RSOs in version 2 are generated based on the 30-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. Due to the extended length of the constellation, there is no need to concatenate several constellations for day-overlapping arcs. The accuracy of the LEO RSOs is at the level of 1-2 cm in terms of SLR validation. Each solution in version 2 is given in the Conventional Terrestrial Reference System (CTS) based on the IERS 2010 conventions and related to the ITRF-2014 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: This data publication provides a collection of ground-motion simulation output for potential future earthquakes in the Rhine Graben area, Germany. Such data can be used as input for other engineering calculations, such as dynamic response history analysis. The earthquake sources used for the simulation consist of a stochastic catalog. They were generated using the German national seismic hazard model, the event-set calculator in the OpenQuake engine (Pagani et al., 2014), and considering both areal seismic source and known tectonic faults in the area as seismic sources in the analyses (branch C in Grünthal et al.,2018). The generated events represent a possible realization of the seismicity in the area within 10,000 years with peak ground accelerations greater than 0.02g. To build the simulation database, ground-motion simulations are performed using these potential future earthquakes from stochastic catalog and adopting the simulation method of Graves and Pitarka (2010, 2015) implemented in the Southern California Earthquake Center (SCEC) broadband platform (BBP), which is tailored for use in the Rhine Graben, as discussed in Razafindrakoto et al. (2021). Here, the approach used to simulate the ground-motion is only briefly discussed; a more accurate description is given in Razafindrakoto et al. (2021), discussing the calibration and validation of ground-motion in the Rhine Graben area. Accordingly, the provided data consists of a simulation output of 284 scenario earthquakes at 76 virtual stations in the Rhine Graben area. The files provided here include the earthquake source, station information, and the simulation results in terms of time histories for individual simulation in one zip file, and a flatfile that combines various intensity measures for all sources and stations.

Description: This dataset provides Rapid Science Orbits (RSO) from the Low Earth Orbiter (LEO) satellite TanDEM-X. 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 TanDEM-X RSO cover the period: from 2010 173 to up-to-date The LEO RSOs in version 2 are generated based on the 30-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. Due to the extended length of the constellation, there is no need to concatenate several constellations for day-overlapping arcs. The accuracy of the LEO RSOs is at the level of 1-2 cm in terms of SLR validation. Each solution in version 2 is given in the Conventional Terrestrial Reference System (CTS) based on the IERS 2010 conventions and related to the ITRF-2014 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. Additional Information Orbital products describe positions and velocities of satellites, be it the Global Navigation Satellite System (GNSS) satellites or Low Earth Orbiter (LEO) satellites. These orbital products can be divided into the fastest available ones, the Near Realtime Orbits (NRT), which are mostly available within 15 to 60 minutes delay, followed by Rapid Science Orbit (RSO) products with a latency of two days and finally the Precise Science Orbit (PSO) which, with a latency of up to a few weeks, are the most delayed. The absolute positional accuracy increases with the time delay.

Description: This data set includes overviews depicting the surface evolution (time-lapse photography, topography analysis, digital image correlation [DIC] analysis), as well as and progressive physical cross-section analysis of 18 laboratory experiments (analogue models) testing the influence of rheologically weak layers (i.e. layers with [a component of] viscous behaviour) and basal fault kinematics on deformation in the weak layer’s overburden. This model set-up was inspired by the geological situation in the Swiss Alpine Foreland. All experiments were performed at the Tectonic Modelling Laboratory of the University of Bern (UB). Detailed descriptions of the model set-up preparation and results, as well as the monitoring techniques can be found in Zwaan et al. (in review).