ALBERT

Description: Der Bereich des Meßtischblattes 6311 Lauterecken im Saar-Nahe-Gebiet (SW-Deutschland) wurde anhand einer geologischen, ingenieurgeologischen, hydrogeologischen und morphologischen Untersuchung einer Stabilitätsanalyse der Hänge und Böschungen unterzogen, die durch die Verwertung klimatologischer Daten vervollständigt wurde. Das Ergebnis liegt in einer Stabilitätskarte sowie in einer Analyse der gesammelten Daten vor. Soweit die Untersuchung des Modellgebietes von ca. 130 km21 Größe (etwa 5% der Fläche des Saar-Nahe-Gebietes) eine Antwort zuläßt, sind Hänge und Böschungen im sedimentären Rotliegenden des Saar-Nahe-Gebietes bereits ab 7° Hangneigung potentiell rutschgefährdet. Das rutschgefährdete Areal umfaßt etwa 10% der untersuchten Fläche. Ca. 2,6% wurden von Massenbewegungen betroffen. Kriechen und Gleiten sind die häufigsten Arten der Massenbewegungen. Die beteiligten stratigraphischen Einheiten sind neben den Deckschichten die Quirnbacher, Jeckenbacher und Lautereckener Schichten des Unteren Rotliegenden. Künstliche Böschungs-, An- und Einschnitte in den für das Unterrotliegende charakteristischen Wechsellagerungen von Ton-, Schluff- und Sandsteinen, stellen ein permanentes Stabilitätsproblem dar.

Description: Abstract: This report deals with the analysis of stability of slopes which occur on the map of Lauterecken, Saar-Nahe-area, SW-Germany. A geological, engineering geological, hydrogeological and morphological study was made, additionally, climatological data were taken into account; the results of it are analyzed and plotted in a stability map. Conclusions: Taking the regarded territory of approximately 130 km2 (about 5% of the area of the Saar-Nahe-area), it can be stated that slopes in the Saar-Nahe-area are potential landslide areas, if the inclination of the slopes is 7° or more. Within an area of 10% landslides are probable to take place. Within 2,6% mass movements happened or are going on. Creep and sliding are the most abundant forms of mass movements. Slope instability occours preferentially in weathered rocks, Quirnbach beds, Jeckenbach beds and Lauterecken beds of the Lower Permian. Steep roadcuts occurring in alternating sandstone and siltstone beds are very likely to cause stability problems.

Description: research

Description: Trotz der am 2. August 1518 erlassenen Bergordnung kam es in den Folgejahren immer wieder zu Auseinandersetzungen zwischen den Bergleuten und den Bergbeamten. Hintergrund waren neben der wachsenden Korruption auch Betrug, Misswirtschaft und Machtmissbrauch der Bergbeamten, dem durch den rasant wachsenden Bergbau Tür und Tor geöffnet war. Mutmaßlich inspiriert durch die Bauernkriege kam es am 20. Mai 1525 zu einem Aufstand der Bergleuten in Joachimsthal. Nach der raschen Beilegung der Auseinandersetzung wurde zu der weiterhin gültigen Bergordnung vom 2. August 1518 eine Ergänzung mit 35 Artikeln erlassen.

Description: source

Description: Geologische Karte 1: 25 000 mit Erläuterungen. Digitalisat des FID GEO (Fachinformationsdienst Geowissenschaften), erstellt durch das GDZ (Göttinger Digitalisierungszentrum), Karte aus dem Bestand der SUB Göttingen. Koordinaten Vorlage: Nullmeridian Ferro E 033 40 - 033 50 / N 052 54 - 052 48.

Description: map

Description: DFG, SUB Göttingen

Description: Die biostratigraphische Aussagekraft organischwandiger Dinoflagella- tenzysten in Rupel-Sedimenten (Unter-Oligozän) des Mainzer Beckens wird anhand von Material aus fünf Kernbohrungen aus verschiedenen Ablagerungsräumen untersucht. Die Abfolge vom oberen Foraminiferenmergel bis in den unteren Schleichsand lässt sich durch das Aussetzen von Wetzeliella gochtii, Rhombodinium draco, Phtanoperidinium amomum, P. comatum, W. symmetrica und Enneadocysta pectiniformis in vier Abschnitte gliedern. Ein Vergleich mit Dinoflagellatenzysten-Zonierungen für den nordwesteuropäischen Raum ergibt die größten Übereinstimmungen mit der Zonierung von Köthe (1990). Dies weist auf eine enge paläozeanographische Verbindung zwischen dem Mainzer Becken und dem nordwestdeutschen Tertiärbecken zur Zeit des Rupels hin.

Description: Abstract: The biostratigraphic significance of organic-walled dinoflagellate cysts from Rupelian (Lower Oligocene) sediments of the Mainz Basin (Southwest Germany) is investigated. The study material is derived from five boreholes drilled in different depo- sitional environments. The investigated succession can be subdivided into four intervals based on the last appearance data of Wetzeliella gochtii, Rhombodinium draco, Phtanope- ridinium amomum, P. comatum, W. symmetrica, and Enneadocysta pectiniformis. A comparison of dinoflagellate cyst ranges in the Mainz Basin with zonations from the Northwest European Tertiary Basin yields highest agreement with the zonation of Köthe (1990) which has been established for northern Germany. This indicates a close palae- oceanographic connection between the Mainz Basin and the Northwest European Tertiary Basin during Rupelian times.

Description: research

Description: In verschiedenen Hanglagen der Ortsgemeinde Essenheim in Rheinhessen (Rheinland-Pfalz) ist der Untergrund rutschgefährdet oder es sind fossile Rutschungen vorhanden. In einer dieser Hanglagen wurde die Erweiterung des Baugebietes „Domherrngärten" geplant. In der Folge dessen war zu klären, unter welchen Randbedingungen die Bebauung realisiert werden kann. Hierzu wurden in mehreren Kampagnen der geologische Untergrund mit Kernbohrungen untersucht und Inklinometermessstellen zur Beobachtung von Hangbewegungen eingerichtet. Die Untersuchungsergebnisse wurden im Rahmen einer Bachelorarbeit zur Durchführung von Standsicherheitsberechnungen genutzt. Auf der Basis aller Untersuchungsergebnisse werden Vorsorgemaßnahmen für die Bebauung in einem rutschgefährdetem Hang aufgezeigt.

Description: Abstract: Various slopes in the village Essenheim in Rhinehessen/ Rhineland-Pala- tinate are prone to landslides. The planed extension of the building area „Domherrngärten II" is part of such an area. In succession it had to be discussed under which circumstances construction is possible. To analyze the geological features core drillings with rock sampling were executed as well as inclinometers (measurements to detect motion of the slope). The taken data was used in a Bachelor thesis to evaluate the slope stability. On the base of all results references for building on instable slopes are given.

Description: research

Description: In this paper, the authors discuss the role of China in the emerging geopolitics of hydrogen. It begins with a review of China's external energy policy and its evolution over the past decades, highlighting China's transition to a net-energy importer as an important inflection point in that process. It then goes on to describe the main pillars of China's national hydrogen policy. Building on this the paper provides and overview of China's external hydrogen policy and how this aligns with both its broader energy foreign policy and its hydrogen policy objectives. The paper finds that China’s hydrogen strategy – both internal and external – are still at an emergent stage. National targets remain modest, and policy remains ambiguous regarding the preferred production pathway. China’s long-term vision clearly emphasizes the role of renewable hydrogen to help balance an energy system dominated by wind and solar energy. However, current policy provides ample space for the promotion of other forms of hydrogen production. Rather, than a strong, centralized policy approach, local and provincial governments along with SOEs have been driving investment and policy experimentation in the sector, which includes efforts to boost fossil-based hydrogen production.

Description: This chapter reviews Japan’s hydrogen strategy with a particular focus on its international elements. It begins by outlining Japan’s international commitment to reduce economy-wide greenhouse gas emissions. The chapter then reviews Japan's domestic policy settings designed to support the deployment of hydrogen in power generation, transport, and industrial uses. The chapter then reviews the strategy that the government is using to enable the development of international supply chains to enable the required imports to satisfy projected hydrogen use in the country. It outlines bilateral technology partnerships and international activities within multilateral forums. It concludes with a short discussion of the geopolitical implications of Japan's hydrogen strategy. Japan has been at the forefront of global efforts to increase the role of hydrogen and ammonia as an option for supporting decarbonization. Japan’s government is positioning hydrogen to play a large role in its overall decarbonisation strategy in support of its mid-century, net zero emissions reduction goal. In this context, the Japanese government is supporting the development of technologies on both the supply and demand side, informed by its understanding of feasible decarbonization pathways domestically and the industrial policy opportunities it has identified to promote Japan's technological leadership. Key features of Japan’s strategy are the central focus on the need to import hydrogen and ammonia and the emphasis domestically on the use of hydrogen and ammonia co-combustion in existing thermal power generation as a transition technology, which is not emphasised in other countries’ national hydrogen strategies. In addition, the Japanese government is championing hydrogen and ammonia internationally through forums such as AZEC, which includes proposing ammonia as a technology option for reducing emissions from the power sector in the Asia-Pacific. A key near-term focus on the supply-side is testing the feasibility of different technology options for hydrogen transport, based on the strong emphasis on hydrogen and ammonia imports within Japan’s hydrogen strategy. Coupled with the potential for exporting technologies for hydrogen use, this suggests that new patterns of trade and investment may emerge, although there remain crucial questions about commercial feasibility in addition to technical challenges. Indeed, Japan’s hydrogen strategy is predicated on the ability to build international supply chains at scale. These are currently being enabled by public investment in early-stage projects. These testing different technology options to enable the export of hydrogen to Japan to support domestic decarbonization. Another challenge lies in unlocking hydrogen demand given that processes using hydrogen and ammonia remain more expensive than alternatives in most cases. A case in point is FCVs, in which consumer demand remains far lower than envisioned. In response, the Japanese government is developing a series of policies to reduce the gap between hydrogen and ammonia and best available technologies. The revised 2023 NHS also signalled a shift towards emphasising Japan’s technology leadership in fuel cells and taking a more neutral approach towards end-use sectors. We can expect Japan’s national hydrogen strategy to continue to develop in response to the effectiveness of policies implemented domestically and internationally to increase the demand for, and supply of hydrogen and associated vectors.

Description: Im Rahmen des Internationalen Heringslarven Surveys im September 1999 wurden vom Institut für Meereskunde in Kiel Planktonproben zur Untersuchung von Verteilungsmustern auf einer Dauerstation östlich der Orkney-Inseln in der Nordsee genommen. Dabei kamen zwei Geräte zum Einsatz: der Meßhai und der Ichthyoplanktonrekorder (IPR). Anhand der Daten aus den Meßhaifängen wurde die Vertikalverteilung von Heringslarven auf der Dauerstation in Bezug auf die Umweltbedingungen über einen Zeitraum von vier Tagen untersucht. Die Heringslarven zeigten eine deutliche Wanderbewegung in Abhängigkeit der Tageszeit. Am Tage waren die höchsten Larvenkonzentrationen in mittleren und oberflächennahen Wasserschichten zu finden. In der Nacht zeigten kleinere Larven (〈10 mm) und Larven der Größenklasse 15-16mm eine homogenere Verteilung über die Wassersäule. Die größeren Larven (≥16mm) zeigten ein ausgeprägteres Wanderverhalten zwischen Tag und Nacht. Mögliche Gründe für die Verteilungsmuster der Larven werden diskutiert. Anhand der IPR-Daten konnten Verteilungsmuster für Heringslarven und andere Planktonorganismen dargestellt werden. Eine schlüssige Interpretation der Ergebnisse war hier allerdings aufgrund zu geringer Vergleichsauswertungen nicht möglich. Es wurden jedoch Erfahrungen bezüglich der Auswertung der IPR-Daten gesammelt und Möglichkeiten zukünftiger Einsätze diskutiert.

Description: The area of investigations belongs to the subtidal (7-16 m depth) and is mostly covered by fine sand with spots of coarse sand in between. Based on the sediment distribution, two associations can be differentiated: fine and coarse sands, with smooth transitions (mixed and silty sediments). The species belonging to the different associations correspond with those of earlier investigations (ZIEGELMEIER 1963, STRIPP 1969, RACHOR & GERLACH 1978, ZIEGELMEIER 1978, RA CHOR 1980, SALZWEDEL et al. 1985, 1990, NIERMANN 1991 ), except for the new invader, the bivalve Ensis directus. During this study fluctuations in number of species and individuals could be observed. Diversity and evenness decreased in spring 2001 due to strong recruitment of polychaeta, but mainly of Ensis directus. 23 years after the invasion, Ensis directus is an important member of the sandy subtidal areas which are exposed to currents with a mean abundance of 925 m-2. E. directus does not seem to prefer special habitats. Their locomotion capacity above and within the sediment enables this species to react quickly on bottom disturbances and thus to survive in current exposed habitats. The mussel shows extremely high abundances (1972 respectively 5481 m-2) on fine and silty fine sands. During this study mainly one and two year old razor shells were found, some with a maximum age of 3.5 years. E. directus is an opportunistic species with mass development (MOHLENARDT-SIEGEL et al. 1983), high recruitment(〉 25000 m-2 in July 2001) and strong growth (3.6 mm month-1). Additionally, the mass mortalities (mortality of 77 respectively 84 % year-1) were observed, the reasons for that are not known yet. The interaction between low temperature and limited movement could be responsible for the washing out of the individuals. Since mortality takes place especially in springtime, the reasons could be the depletion after spawning aswell. Spisula solida was found regularly in the investigation area (frequency: 64 %), but in low numbers (mean abundance: 5 m-2). In coarse sand locally higher abundances were found (13 m-2). The surf clam is one of three dominant species (11 %) in this area. Just as E. directus, S. solida is a fast burrowing mussel (KOCK 1995) and therefore adapted to exposed sedimentary habitats. Nevertheless, the abundances in 2000 2001 lie well below values of those of the mid 90ies (MEIXNER 1993, 1994, KOCK 1995). This can also be seen in the decreasing landings of surf clams since the middle of the 90ies. Whether the effects of the ice winter 1995/96 or other reasons are responsible for the disappearance of S. solida, remains unclear. In the investigation area mainly small individuals were found (mean length: 9,7 mm). Due to the low figures in the sample neither growth rate nor recruitment or structure of the stock could be studied. The study shows the gap between the stocks of E. directus and S. solida, as well as fishery in the North Sea. Various details of the species biology remains unclear. Therefore supporting studies are necessary to ensure sustainable fishery.

Description: Mit der hier vorgestellten Software DANA wurden RAFOS-Daten aus dynamisch und geographisch unterschiedlichen Regionen untersucht. Als Untersuchungskriterien werden Lagrange'sche Zeit- und Langenskalen, mittlere kinetische und Wirbelenergie, Diffusivitat, Wirbelstatistiken und Geschwindigkeitsspektren verwendet. Zerlegt man die gemessene Strömungsgeschwindigkeit in Mittel und Fluktuation gemafl u = u+u', so wird die mittlere Zirkulation offensichtlich durch den ersten Term, alle anderen genannten Größen jedoch durch den zweiten Term beschrieben. Der Schwerpunkt liegt also auf der Beschreibung des turbulenten Feldes und insbesondere der Autokorrelation der Geschwindigkeitszeitreihen: Die integrale Zeitskala ist das Integral über die Autokorrelation, das Spektrum ihre Fourier-Transformierte und die Wirbelenergie die Gesamtvarianz. Im Islandbecken bei 1500 und 2600 Meter Tiefe liegt demnach ein aktives Gebiet mit erhöhter Wirbelenergie und Vermischung vor. Es werden Bewegungen auch auf kurzen Zeitskalen und circa doppelt so viele zyklonale wie antizyklonale Wirbel beobachtet, die somit wohl einen wesentlichen Teil zur Energie und Vermischung beitragen. Entlang des Reykjanes-Rückens fließt ein Randstrom, der vom Island-Schottland Overflow gespeist wird; in seinem nördlicheren Teil mäandriert er kaum, während er kurz vor Erreichen der Gibbs-Bruchzone deutlich instabiler wird. Südlich schließt sich das westeuropäische Becken an, das mit Floats in 1750 Meter Tiefe beprobt wurde. Dies liegt in der gleichen Wassermasse, doch es zeigt sich ein deutlich weniger energetisches Gebiet mit insgesamt weniger Wirbelereignissen in Relation zur Gesamtdatenmenge. Entsprechend sind die Zeitskalen auch länger. Im tropischen, westlichen Atlantik östlich der Karibik ist die Bewegung im Niveau des Antarktischen Zwischenwassers bei 780 Meter Tiefe durch großräumige Turbulenz geprägt, wobei die Längen- und Zeitskalen größer sind als bei den hier beschriebenen Messungen aus dem Islandbecken. Am Westrand nehmen die Zeitskalen ab und die Wirbelenergie zu. In einer Tiefe von 1400 Metern im Niveau des oberen Nordatlantischen Tiefenwassers fließt wieder ein westlicher Randstrom längs der Topographie, und im Beckeninnern ist die Bewegung weniger energetisch als in 780 Meter Tiefe. Die Umgebung der Südspitze Afrikas im Zwischenwasser (600-1200 Meter Tiefe) ist durch die hohen kinetischen Energien des Agulhas-Stromes geprägt, der an verschiedenen Orten verschieden stationär ist. Nordwestlich seiner Retroflexion liegt eine Region starker Wirbelaktivität, in der die Rolle der bisher überwiegend diskutierten Agulhas-Ringe zugunsten von zyklonaler Wirbelaktivität modifiziert werden muß. Weiter im Atlantik nehmen die Wirbelenergie rasch ab und die Zeitskalen zu.

Description: The macrofauna in soft sediments of the deep seafloor is generally diverse and represents a comparatively well-studied faunal group of deep-sea ecosystems. In the abyss of the Clarion Clipperton Fracture Zone (CCFZ) in the NE Pacific, macrofauna are major contributors to benthic biodiversity. Their distribution, composition, and diversity have been frequently investigated to assess the potential impacts of future mining activities on the resident fauna. In this study, patterns of densities and community structure of CCFZ macrobenthic infauna and their relationships with a range of environmental and climatic variables were examined, with a special focus on communities from the eastern German contract area (referred to as BGR CA). However, comparisons were also made with other contractor areas (e.g., IFREMER, IOM, GSR) and one Area of Particular Environmental Interest (APEI3). Material for this study was obtained by means of a box corer during six expeditions to the CCFZ between 2013 and 2018 resulting in 148 samples. Our study uncovered notable spatial and temporal variations in both faunal densities and community composition. While areas within the BGR CA exhibited a similar community composition, slight differences were observed between the various CAs and APEI3. Surprisingly, we found an unexpected negative correlation between food availability and both macrofaunal density and community structure that may be attributed to differences in sampling methodologies and pronounced temporal variation. Furthermore, we explored the impact of climatic fluctuations associated with the El Niño/Southern Oscillation (ENSO) on macrofaunal densities, observing an increase during warm (El Niño) events. Our findings underscore the challenges of accurately assessing spatial and temporal variations in the absence of standardised sampling protocols. Hence, we emphasize the importance of adopting standardised protocols to enhance data comparability, thereby fostering a deeper understanding of the underlying factors influencing spatial and temporal changes in macrofauna community structure within the CCFZ.

Description: Many geophysical inversion methods rely on simulating wave propagation. With the advent of advanced computing systems and the need for precise forward models for Full Waveform Inversion (FWI) and Reverse Time Migration (RTM) applications, elastic wave modeling has attracted more attention. In order to solve the wave equation, which is a Partial-Differential-Equation (PDE), using numerical methods such as Finite Difference (FD), an absorbing layer is defined at the boundaries of the model to avoid unwanted reflections. In wave simulations, a perfectly matched layer (PML) is a highly effective absorbing layer. In many simulations, applying a second-order equation system is simpler and more practical. Despite its usefulness, extending PML to second-order systems generates some difficulties because the method was originally designed for first-order systems. This paper proposes an unsplit PML implementation for the second-order heterogeneous elastic wave equation by making use of the auxiliary differential equations. This method has a lower computing cost compared to earlier studies and can be easily incorporated into existing codes. Numerical examples indicate the method’s satisfactory performance.

Description: Predatory non-indigenous species (NIS) have profound impacts on global ecosystems, potentially leading to native prey extinction and reshaping community dynamics. Among mechanisms potentially mediating predator impacts and prey invasion success are predator preferences between native vs. non-indigenous prey, a topic still underexplored. Using functional response and prey preference experiments, this study focused on the predation by the non-indigenous Japanese brush-clawed shore crab, Hemigrapsus takanoi, between the native gammarid Gammarus duebeni and the analogous non-indigenous Gammarus tigrinus. Although H. takanoi showed subtle differences in its functional response type between the two prey species, its preferences across their environmental frequencies were not strongly influenced by the prey invasion scenario. The findings highlight the need for a comprehensive understanding of interactions in ecosystems with multiple NIS, offering fresh insights into complex feeding interactions within marine environments.

Description: Highlights • a high-fidelity RANS CFD method is used to simulate the flow through netting panels. • The influence of netting solidity, twine diameter, mesh opening angle and incident angle is examined. • Mesh opening angle, solidity and angle of incidence greatly influence the hydrodynamic force coefficients and efficiency. To ensure the economic and environmental sustainability of the fisheries and aquaculture industries, it is necessary to address issues related to fuel consumption, environmental degradation, and fish welfare. Hence, we need a thorough understanding of the filtration efficiency and the hydrodynamic forces acting on towed fishing gears and netting structures. Here we apply a Reynolds-averaged Navier-Stokes (RANS) CFD method to model the flow through netting panels, where we vary the operational and design parameters of flow speed, netting solidity, twine diameter, mesh opening angle and the incidence angle of the flow to the panel. Thus, we create a simulated data set which we analyze to provide a fundamental understanding of the functional relationships for the pressure drop and tangential drag coefficients, and the flow deflection in terms of these parameters. We pay particular attention to the effect of mesh opening angle, a parameter that has not received much attention in the literature. We demonstrate that it has a large influence on the drag and lift coefficients and consequently on the hydrodynamic efficiency of netting panels. These results will be particularly useful for reducing the hydrodynamic forces on netting structures and improving the fuel efficiency of towed fishing gear operations.

Description: 5 – 25 July 2023, Kiel (Germany) – Tallinn (Estonia) – Kiel (Germany) CYANO-OC

Description: The distribution of water masses, and the ventilation rates of these, are of significance to the thermohaline circulation and biogeochemistry of the world oceans. The distribution of the main water masses in the Atlantic Ocean is published in a companion study (Liu and Tanhua, 2021), their ages and ventilation time-scales are reported here by using observations of the transient tracers, CFC-12 and SF6. Two different definitions of water mass ages are presented; the mean-age representing an average age of a water mass, and the mode-age that better represents the advective time-scale. In general, ages increase with pressure and along the pathway of a water mass. The central waters in the upper layer obtain the mean-ages of up to ~100 years and the mode-ages of up to ~30 years. In the intermediate layer, the Antarctic Intermediate Water (AAIW) and the Mediterranean Water (MW) show gradients of water mass ages in the meridional and zonal direction respectively. The AAIW obtains the highest mean-age of ~300 years and mode-age of ~80 years at 30° N, while the MW shows the highest mean-age of ~400 years and mode-age of ~100 years in the equator region. As the dominant water mass in the deep and overflow layer, the North Atlantic Deep Water (NADW) from high northern latitudes obtains the highest mean-age of ~600 years and mode-age of ~100 years in the Antarctic Circumpolar Current (ACC) region at 50° S. In the bottom layer, the Antarctic Bottom Water (AABW) from the Weddell Sea obtains the highest mean-age of ~600 years and mode-age of ~100 years in the equator. As the continuation of AABW, the Northeast Atlantic Bottom Water (NEABW) obtains the highest mean-age of ~800 years and mode-age of ~120 years at 50° N. The mode-age increases with the transport distance from formation area, accompanied by significant differences between the eastern and western basins. The mode-age is used to calculate the oxygen utilization rate (OUR) with apparent oxygen utilization (AOU) during the active transport in water masses. The western basin exhibits lower mode-age with higher oxygen (low AOU) due to the better ventilation. The OUR shows similar distribution to dissolved oxygen (DO), indicating higher oxidation rate in the high oxygen region.

Description: Gypsum makes up about one fifth of giant salt deposits formed by evaporation of seawater throughout Earth’s history. Although thermodynamic calculations and precipitation experiments predict that gypsum precipitates when the salinity of evaporating seawater attains about 110 g kg-1, gypsum deposits of the Mediterranean Salt Giant often bear the geochemical signature of precipitation from less saline water masses. Addressing this geochemical riddle is important because marine gypsum deposition and continental gypsum erosion affect the global carbon cycle. We investigated gypsum deposits formed in the marginal basins of the Mediterranean Sea during the Messinian Salinity Crisis (about 6 million years ago). These often bear low-salinity fluid inclusions and isotopically light crystallization water, confirming previous published reports that the Mediterranean Salt Giant harbors low-salinity gypsum deposits. A geochemical model constrained by fluid inclusion salinity and isotope (87Sr/86Sr, δ34SSO4, δ18OH2O, δDH2O) measurements excludes that Ca2+- and SO42--enriched continental runoff alone provides the trigger for gypsum precipitation at low salinity. We propose that, concurrent with the prevalent evaporative conditions and with Ca2+- and SO42--bearing runoff, the biogeochemical sulfur cycle is capable of producing a spatially-restricted and temporally-transient increase of Ca2+ and SO42- within benthic microbial mats, creating local chemical conditions conductive to gypsum precipitation. This hypothesis is supported by the presence of dense packages of fossils of colorless sulfur bacteria within gypsum in several Mediterranean marginal basins, together with independent geochemical and petrographic evidence for an active biogeochemical sulfur cycle in the same basins. Should this scenario be confirmed, it would expand the range of environments that promote marine gypsum deposition; it would also imply that an additional, biological coupling between the calcium, sulfur and carbon cycles exists.

Description: Spatial predictions of total organic carbon (TOC) concentrations and stocks are crucial for understanding marine sediments’ role as a significant carbon sink in the global carbon cycle. In this study, we present a geospatial prediction of TOC concentrations and stocks at a 5 x 5 arc minute grid scale, using a deep learning model — a novel machine learning approach based on a new compilation of over 22,000 global TOC measurements and a new set of predictors, such as seafloor lithologies, grain size distribution, and an alpha-chlorophyll satellite data. In our study, we compared the predictions and discuss the limitations from various machine learning methods. Our findings reveal that the neural network approach outperforms methods such as k Nearest Neighbors and random forests, which tend to overfit to the training data, especially in highly heterogeneous and complex geological settings. We provide estimates of mean TOC concentrations and total carbon stock in both continental shelves and deep sea settings across various marine regions and oceans. Our model suggests that the upper 10 cm of oceanic sediments harbors approximately 171 Pg of TOC stock and has a mean TOC concentration of 0.68 %. Furthermore, we introduce a standardized methodology for quantifying predictive uncertainty using Monte Carlo dropout and present a map of information gain, that measures the expected increase in model knowledge achieved through in-situ sampling at specific locations which is pivotal for sampling strategy planning.

Description: While basaltic volcanism is dominate during rifting and continental breakup, felsic magmatism may also comprise important components of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing dacitic, pyroclastic unit was recovered within early Eocene sediments on Mimir High (Site U1570), a marginal high on the Vøring transform margin. Here, we present a comprehensive textural, mineralogical, and petrological study of the dacite in order to assess its melting origin and emplacement. The major mineral phases (garnet, cordierite, quartz, plagioclase, alkali feldspar) are hosted in a fresh rhyolitic, highly vesicular, glassy matrix, locally mingled with sediments. The xenocrystic major element chemistry of garnet and cordierite, the presence of zircon inclusions with inherited cores, and thermobarometric calculations all support a crustal metapelite origin. While most magma-rich margin models favor crustal anatexis in the lower crust, thermobarometric calculations performed here show that the dacite was produced at upper-crustal depths (〈 5 kbar) and high temperature (750–800 °C) with up to 3 wt% water content. In situ U-Pb analyses on zircon inclusions give a magmatic age of 54.6 ± 1.1 Ma, revealing the emplacement of the dacite post-dates the Paleocene-Eocene Thermal Maximum (PETM). Our results suggest that the opening of the North Atlantic was associated with a phase of low-pressure, high-temperature crustal melting at the onset of the main phase of magmatism.

Description: The dynamic processes associated with subducting tectonic plates and rising plumes of hot material are typically treated separately in dynamical models and seismological studies. However, various types of observations and related models indicate these processes overlap spatially. Here we use precursors to PP and SS reflecting off mantle transition zone discontinuities to map deflections of these discontinuities near three subduction zones surrounding the Caribbean Plate: 1) Lesser Antilles, 2) Middle America and 3) northern South American subduction zones. In all three regions slow seismic anomalies are present behind the sinking slab within the transition zone in tomographic images. Using array methods, we identify precursors and verify their in-plane propagation for MW ≥ 5.8 events occurring between the years 2000 and 2020 by generating a large number of source receiver combinations with reflection points in the area, including crossing ray paths. The measured time lag between PP/SS arrivals and their corresponding precursors on robust stacks are used to measure the depth of the mantle transition zone discontinuities. In all three areas we find evidence for upward deflection of the 660 discontinuity behind the sinking slab, consistent with the presence of hot plume material (average temperature anomalies of 180 to 620 K), while there is not a corresponding downward deflection of the 410 km discontinuity. One interpretation of these disparate observations is suggested based on comparison to existing models of mantle convection and subduction: plume material rising across 660 km discontinuity could be entrained by lateral flow in the transition zone induced by the nearby sinking slab, and thus delaying the rise of hot material across the 410 km discontinuity.

Description: Observations of spatio-temporal variability of the deep ocean are rare and little is known about occurrence of deep ocean mesoscale dynamics. Here, we make use of 2.5 years of time series data from three distributed sensor arrays, which acquired high-resolution temperature, pressure and sound speed data of the bottom layer offshore northern Chile. Estimating salinity and density from the direct observations enable access to the full spectrum of hydrographic variability from a multi-hourly to annual time scale and with average inter-station distances of less than 1 km. Analyses revealed interannual warming over the continental slope of 0.002 °C yr−1–0.003 °C yr−1, and could trace periodic hydrographic anomalies, likely related to coastal-trapped waves, as far as to the lower continental slope. A concurrent change in the shape of the warm anomalies and the rate of deep-sea warming that occurs with the crossing of the deep-sea trench suggests that the abyssal part of the eastern boundary current system off Chile does not extend past the deep sea trench. Furthermore, the comparison of anomaly timing and shape in between stations implies southwards flow over the mid to lower continental slope, centred closer to the trench.

Description: Ocean alkalinity enhancement (OAE) is a negative emissions technology (NET) that shows significant potential for climate change mitigation. By increasing the bicarbonate ion concentration in ocean water, OAE could enhance long-term carbon storage and mitigate ocean acidification. However, the side effects and/or potential co-benefits of OAE on natural planktonic communities remain poorly understood. To address this knowledge gap, a mesocosm experiment was conducted in the oligotrophic waters of Gran Canaria. A CO2-equilibrated total alkalinity (TA) gradient was employed in increments of 300 µmol L−1, ranging from ∼ 2400 to ∼ 4800 µmol L−1. This study represents the first attempt to evaluate the potential impacts of OAE on planktonic communities under natural conditions. The results show that net community production (NCP), gross production (GP), community respiration (CR) rates, and the metabolic balance (GP:CR) did not exhibit a linear response to the whole alkalinity gradient. Instead, significant polynomial and linear regression models were observed for all rates up to ΔTA 1800 µmol L−1, in relation to the dissolved inorganic carbon (DIC) concentrations. Notably, the ΔTA 1500 and 1800 µmol L−1 treatments showed peaks in NCP shifting from a heterotrophic to an autotrophic state, with NCP values of 4 and 8 µmol O2 kg−1 d−1, respectively. These peaks and the optimum curve were also reflected in the nanoplankton abundance, size-fractionated chlorophyll a, and 14C uptake data. Furthermore, abiotic precipitation occurred in the highest treatment after day 21, but no impact on the measured parameters was detected. Overall, a damaging effect of CO2-equilibrated OAE in the range applied here on phytoplankton primary production, community metabolism, and composition could not be inferred. In fact, a potential co-benefit to OAE was observed in the form of the positive curvilinear response to the DIC gradient up to the ΔTA 1800 treatment. Further experimental research at this scale is key to gain a better understanding of the short- and long-term effects of OAE on planktonic communities.

Description: Highlights • Ankaramites are Ca-rich and Ni-poor porphyritic basalts that are common in oceanic arcs. • Melt inclusions from Kibblewhite Volcano show similar compositions to ankaramites. • Ankaramite is a primary magma component in oceanic arcs. • Interaction between melt and mantle can produce ankaramitic melts. • Harzburgite formed by melt-mantle interactions is the source of high-Mg andesites. Abstract Ankaramites, which are clinopyroxene-rich basalts with primitive whole-rock compositions (Mg# 〉65), are common in oceanic arcs and are characterized by high whole-rock CaO/Al2O3 (〉1.0) ratios and olivine crystals with anomalously low nickel contents (〈0.2 wt% NiO). These geochemical characteristics cannot be explained by the melting of ordinary mantle peridotite. However, their origin is critical for understanding the formation of primary magmas in oceanic arcs. Here, we investigated olivine-hosted melt inclusions (MIs) from ankaramites and magnesian andesites of the Kibblewhite Volcano in the Kermadec arc. The MIs from the ankaramites have similar major and trace element characteristics to the host rocks, indicating that the ankaramites did not result from an accumulation of mafic minerals but rather represent the primary magma in the Kibblewhite Volcano. The MIs from the magnesian andesites were hosted in forsteritic olivine xenocrysts with a wide range of NiO contents (Fo90–92; 0.13–0.39 wt% NiO) and have similar major element compositions to the ankaramites but exhibit a wide range of CaO/Al2O3 (0.85–1.54). The trace element characteristics of the MIs from the magnesian andesites do not match those of the host rocks, indicating that they are not primary melts of the magnesian andesites but primitive basaltic melts generated before the magnesian andesites formed. Interestingly, the CaO/Al2O3 ratio of MIs from the magnesian andesites was negatively correlated with the NiO content of their host olivines. This correlation suggests that the composition of the primary basaltic magmas of the Kibblewhite Volcano changed continuously from peridotite-derived to ankaramitic. This correlation could not be explained by grain-scale process, crustal anatexis, or contribution of slab-derived carbonate-rich fluids. Instead, we propose that this correlation can be explained by the interaction of the ascending primary basaltic melts with the lithospheric mantle. During melt-mantle interaction, the assimilation of clinopyroxene and fractionation of olivine and orthopyroxene caused the CaO/Al2O3 ratio to increase in the melt and the Ni content to decrease. Furthermore, because the magnesian andesites have low CaO/Al2O3 ratios and could be derived from a clinopyroxene-poor mantle lithology, the interaction between the melt and mantle may also be closely related to the origin of the magnesian andesites at Kibblewhite Volcano. This interpretation provides a new perspective on the origin of the oceanic arc ankaramites and why primary andesitic and basaltic magmas coexist in the Kibblewhite Volcano.

Description: Im Ostseeraum fanden in den letzten 20 Jahren zahlreiche Untersuchungen der Wasserdampfhaushaltskomponenten statt. Dabei wurden aber relativ kurze Zeiträume und zum Teil nur einzelne Komponenten betrachtet. Außerdem beschränkten sich diese Studien häufig auf die Ostsee. In dieser Arbeit wird der atmosphärische Wasserhaushalt für den Zeitraum von 1948 bis 2000 betrachtet. Alle Komponenten werden aus den NCEP/NCAR-Reanalysen für das gesamte BALTEX-Gebiet, also für die Ostsee und ihr Wassereinzugsgebiet, bestimmt. Die Untersuchungen zeigen, dass der Wasserdampffluss in der Atmosphäre konvergent ist und zu einer mittleren Zunahme des Wasserdampfes von 247 mm/Jahr führt. Der Wasserdampftransport findet überwiegend zonal von Westen nach Osten statt und ist im Südwesten der BALTEX-Region am größten. Nach Osten und nach Norden nimmt der Wasserdampffluss deutlich ab. Eine Aufteilung des totalen Flusses in den mittleren und den turbulenten Fluss zeigt, dass der turbulente Fluss nur etwa ein Fünftel des mittleren Flusses beträgt. Im Gegensatz dazu trägt die Divergenz des turbulenten Flusses sogar zu etwas mehr als 50 % zur Divergenz des totalen Flusses bei. Wie bei den bisherigen Studien übertrifft der mittlere Niederschlag die mittlere Verdunstung um 140 mm/Jahr. Allerdings ist nach den NCEP-Daten über der Ostsee die Verdunstung etwas größer als der Niederschlag. Dies steht im Gegensatz zu den bisherigen Veröffentlichungen und wird durch den geringen Niederschlag über der Ostsee in den NCEP-Daten verursacht. Bei den Verdunstungswerten gibt es dagegen über der Ostsee gute Übereinstimmungen mit den bisherigen Berechnungen. Mit Hilfe einer EOF-Analyse werden die zeitlichen und räumlichen Variationen der Haushaltskomponenten betrachtet. Es zeigt sich, dass die Nordatlantische Oszillation im Winter einen deutlichen Einfluss auf alle Komponenten ausübt. Die Variationen, die dem BALTEX-Gebiet von aussen aufgeprägt werden, sind sehr groß. Die Wasserdampfbilanz ist lokal nicht geschlossen und auch im räumlichen Mittel gibt es eine Abweichung von über 100 mm/Jahr. Eine Fehlerbetrachtung zeigt, dass in allen Haushaltskomponenten der NCEP-Daten, zumindest lokal, erhebliche Fehler auftreten. Eine korrigierte Wasserdampfbilanz, wobei die Divergenz des Wasserdampfbilanz durch Schließung der Massenbilanz korrigiert wird und der Niederschlag durch Beobachtungsdaten aus dem BALTEX-Programm ersetzt wird, ist deutlich besser geschlossen. Insbesondere über der Ostsee ist die Bilanz nahezu ausgeglichen. Immer noch große Fehler gibt es aber weiterhin im Nordwesten des BALTEX-Gebiets.

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Description: Tertiär-Block [:] Helmut Keupp & Spyridon M. Bellas (in Zusammenarbeit mit Jan Bartholdy und Dimitris Frydas): Neogene development of the sedimentary basins of NW Crete island, Chania Prefecture, South Aegean Arc System (Greece) …3 ; Dimitris Frydas & Helmut Keupp: Biostratigraphical and paleoecological research of Lower Pliocene diatoms and silicoflagellates from northwestern Crete, Greece …119 ; Wilfried Krutzsch: Stratigraphische Tabelle Oberoligozän und Neogen (marin - kontinental) ...153 ; Glenn Fechner: Eine Dinoflagellaten-Zysten-Flora aus der ehern. Ziegeleitongrube bei Welsow (nordöstl. Mark Brandenburg) ...167 ; Rolf Kohring & Thomas Schlüter: Über ein fossiles Harz aus einer Braunkohle (?Eozän) von Gibbsland und Anglesey (Victoria, S-Australien) ...177 ; Mollusken-Block [:] Joachim Gründel, Thierry Pélissié & Michel Guérin: Brackwasser-Gastropoden des mittleren Doggers von la Balme (Causses du Quercy, Südfrankreich) ...185 ; Joachim Gründel: Archaeogastropoda aus dem Dogger Norddeutschlands und des nordwestlichen Polens ...205 ; Joachim Gründel: Gordenellidae n. fam., eine neue Gastropoden-Familie aus dem Dogger und Malm Europas ...255 ; Steffen Kiel & Klaus Bandel: New slit-bearing Archaeogastropoda from the Late Cretaceous of Spain ...269 ; Helmut Keupp: Anomale Muskelleisten bei Ammoniten ...279 ; Thomas Küchler: Nostoceras (Euskadiceras) euskadiense a new ammonite subgenus and species from the higher Upper Campanian (Upper Cretaceous) of northern Spain ...291 ; []

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Description: Several species from various zooplankton taxa perform seasonal vertical migrations (SVM) of typically several hundred meters between the surface layer and overwintering depths, particularly in high-latitude regions. We use OPtimality-based PLAnkton (OPPLA) ecosystem model) to simulate SVM behavior in zooplankton in the Labrador Sea. Zooplankton in OPPLA is a generic functional group without life cycle, which facilitates analyzing SVM evolutionary stability and interactions between SVM and the plankton ecosystem. A sensitivity analysis of SVM-related parameters reveals that SVM can amplify the seasonal variations of phytoplankton and zooplankton and enhance the reduction of summer surface nutrient concentrations. SVM is often explained as a strategy to reduce exposure to visual predators during winter. We find that species doing SVM can persist and even dominate the summer-time zooplankton community, even in the presence of Stayers, which have the same traits as the migrators, but do not perform SVM. The advantage of SVM depends strongly on the timing of the seasonal migrations, particularly the day of ascent. The presence of higher (visual) predators tends to suppress the Stayers in our simulations, whereas the SVM strategy can persist in the presence of non-migrating species even without higher predators.

Description: Scientists have long attempted to explain why closely similar age patterns of death are characteristic of highly diverse human and nonhuman populations. Historical efforts to identify a general "law of mortality" from these patterns that applied across species ended in 1935 when it was declared that such a law did not exist. These early efforts were conducted using mortality curves based on all causes of death. The authors predict that if comparisons of mortality are based instead on "intrinsic" causes of death (i.e., deaths that reflect the basic biology of the organism), then age patterns of mortality consistent with the historical concept of a law might be revealed. Using data on laboratory animals and humans, they demonstrate that age patterns of intrinsic mortality overlap when graphed on a biologically comparable time scale. These results are consistent with the existence of a law of mortality following sexual maturity, as originally asserted by Benjamin Gompertz and Raymond Pearl. The societal, medical, and research implications of such a law are discussed.

Description: The crises of climate change and biodiversity loss are interlinked and must be addressed jointly. A proposed solution for reducing reliance on fossil fuels, and thus mitigating climate change, is the transition from conventional combustion-engine to electric vehicles. This transition currently requires additional mineral resources, such as nickel and cobalt used in car batteries, presently obtained from land-based mines. Most options to meet this demand are associated with some biodiversity loss. One proposal is to mine the deep seabed, a vast, relatively pristine and mostly unexplored region of our planet. Few comparisons of environmental impacts of solely expanding land-based mining versus extending mining to the deep seabed for the additional resources exist and for biodiversity only qualitative. Here, we present a framework that facilitates a holistic comparison of relative ecosystem impacts by mining, using empirical data from relevant environmental metrics. This framework (Environmental Impact Wheel) includes a suite of physicochemical and biological components, rather than a few selected metrics, surrogates, or proxies. It is modified from the “recovery wheel” presented in the International Standards for the Practice of Ecological Restoration to address impacts rather than recovery. The wheel includes six attributes (physical condition, community composition, structural diversity, ecosystem function, external exchanges and absence of threats). Each has 3–5 sub attributes, in turn measured with several indicators. The framework includes five steps: (1) identifying geographic scope; (2) identifying relevant spatiotemporal scales; (3) selecting relevant indicators for each sub-attribute; (4) aggregating changes in indicators to scores; and (5) generating Environmental Impact Wheels for targeted comparisons. To move forward comparisons of land-based with deep seabed mining, thresholds of the indicators that reflect the range in severity of environmental impacts are needed. Indicators should be based on clearly articulated environmental goals, with objectives and targets that are specific, measurable, achievable, relevant, and time bound.

Description: Seismic data analysis often faces the challenge of random noise contamination from various sources. To overcome this, innovative noise attenuation methods utilizing seismic signal properties are needed. This study focuses on efficiently suppressing random noise in the domain of time and frequency by accurately estimating instantaneous frequency using the single-valued group delay characteristic of seismic signals. The time-reassigned synchrosqueezing transform (TSST) and its second-order variant (TSST2) offer high-resolution time-frequency representations (TFRs) for noise suppression. Expanding on these advancements, we propose an efficient noise suppression method that integrates the adaptive thresholding model into the TSST2 framework and employs sparse representation of the TFR through low-rank estimation. This method effectively attenuates noise while preserving essential signal information. The proposed approach operates trace by trace on recorded data, initially transforming it into a sparse subspace using TSST2. The adaptive thresholding model then decomposes the resulting TFR into sparse and semi-low-rank components, achieving a high-resolution and sparse TFR for efficient separation of noise and signal. After noise suppression, the seismic data can be fully reconstructed by inversely transforming the semi-low-rank component data into the time domain. This method addresses previous limitations in noise attenuation techniques and provides a practical solution for enhancing seismic data quality.

Description: A novel strain, MA3_2.13T, was isolated from deep-sea sediment of Madeira Archipelago, Portugal, and characterized using a polyphasic approach. This strain produced dark brown soluble pigments, bronwish black substrate mycelia and an aerial mycelium with yellowish white spores, when grown on GYM 50SW agar. The main respiratory quinones were MK-10(H4), MK-10(H6) and MK-10(H8). Diphosphatidylglycerol, phosphatidylethanolamine, three unidentified phospholipids and two glycophospholipids were identified as the main phospholipids. The major cellular fatty acids were iso-C16: 1, iso-C16: 0, anteiso-C17: 1 and anteisoC17: 0 . Phylogenetic analyses based on 16S rRNA gene showed that strain MA3_2.13T is a member of the genus Streptomyces and was most closely related to Streptomyces triticirhizae NEAU-YY642T (NR_180032.1; 16S rRNA gene similarity 97.9 %), Streptomyces sedi YIM 65188T (NR_044582.1; 16S rRNA gene similarity 97.4 %), Streptomyces mimosae 3MP-10T (NR_170412.1; 16S rRNA gene similarity 97.3 %) and Streptomyces zhaozhouensis NEAU-LZS-5T (NR_133874.1; 16S rRNA gene similarity 97.0 %). Genome pairwise comparisons with closest related type strains retrieved values below the threshold for species delineation suggesting that strain MA3_2.13T represents a new branch within the genus Streptomyces. Based on these results, strain MA3_2.13T (=DSM 115980T=LMG 33094T) is proposed as the type strain of a novel species of the genus Streptomyces, for which the name Streptomyces profundus sp. nov. is proposed.

Description: Detection of small plastic particles in environmental water samples has been a topic of increasing interest in recent years. A multitude of techniques, such as variants of Raman spectroscopy, have been employed to facilitate their analysis in such complex sample matrices. However, these studies are often conducted for a limited number of plastic types in matrices with relatively little additional materials. Thus, much remains unknown about what parameters influence the detection limits of Raman spectroscopy for more environmentally relevant samples. To address this, this study utilizes Raman spectroscopy to detect six plastic particle types; 161 and 33 nm polystyrene, 〈 450 nm and 36 nm poly(ethylene terephthalate), 121 nm polypropylene, and 126 nm polyethylene; spiked into artificial saltwater, artificial freshwater, North Sea, Thames River, and Elbe River water. Overall, factors such as plastic particle properties, water matrix composition, and experimental setup were shown to influence the final limits of detection.

Description: FS METEOR Expedition M201 VebVolc, 09.06. – 18.07.2024 | Reykjavik – Praia da Vitoria

Description: The disturbance of marine organism phenology due to climate change and the subsequent effects on recruitment success are still poorly understood, especially in migratory fish species, such as the Atlantic herring (Clupea harengus; Clupeidae). Here we used the commercial catch data from a local fisher over a 50-year period (1971–2020) to estimate western Baltic spring-spawning (WBSS) herring mean arrival time Q50 (i.e., the week when 50% of the total fish catches had been made) at their spawning ground within the Kiel Fjord, southwest Baltic Sea, and the duration of the spawning season for each year. The relationship between the seawater temperature in the Kiel Bight and other environmental parameters (such as water salinity, North Atlantic and Atlantic multidecadal oscillations) and Q50 was evaluated using a general linear model to test the hypothesis that fish arrived earlier after warm than cold winters. We also estimated the accumulated thermal time to Q50 during gonadal development to estimate the effects of seawater temperature on the variations of Q50. The results of this study revealed a dramatic decrease in herring catches within the Kiel Fjord since the mid-1990s, as documented for the whole southwestern Baltic Sea. Warmer winter seawater temperature was the only factor related to an earlier arrival (1 week for one January seawater temperature degree increase) of herring at their spawning ground. The relationship was found for the first time on week 52 of the year prior to spawning and was the strongest (50% of the variability explained) from the fourth week of January (8 weeks before the mean Q50 among the studied years). A thermal constant to Q50 (~316°C day) was found when temperatures were integrated from the 49th week of the year prior to spawning. These results indicate that seawater temperature enhanced the speed of gonadal maturation during the latest phases of gametogenesis, leading to an early fish arrival under warm conditions. The duration of the spawning season was elongated during warmer years, therefore potentially mitigating the effects of trophic mismatch when fish spawn early. The results of this study highlight the altering effects of climate change on the spawning activity of a migratory fish species in the Baltic Sea where fast global changes presage that in other coastal areas worldwide

Description: The Banda Sea is of crucial importance for the circulation of the world's oceans, as it is part of the connection between the Pacific to the Indian Ocean. One peculiarity of the upper ocean hydrography in the Banda Sea is the occurrence of barrier layers. The regionality and temporal variability of barrier layer thickness (BLT) in the Banda Sea are examined in this study utilizing in-situ observations and ocean reanalysis output. It is found that a barrier layer occurs in over 90 % of the observational data profiles, and in over 72 % of those profiles, the BLT is shallower than 10 m. Furthermore, we find a seasonal cycle in BLT with a maximum thickness of about 60 m occurring during austral autumn and winter and coinciding with the presence of low saline waters fed by the regional river discharge and rainfall from the Java Sea and Makassar Strait. In addition, we identify the existence of a quasi-permanent anticyclonic circulation cell in the Banda Sea that may support the trapping of surface freshwater by retention. The anticyclonic circulation is most likely wind-driven because it coincides with the regional Ekman pumping pattern. Modulation of the anticyclone is via seasonal variability in the wind stress curl which in turn may explain the efficiency of freshwater retention and thus the BLT. The annual mean BLT distribution in the Banda Sea shows a preferential region of thickened barrier layers around 6o-8oS and 124o-126oE and resampling the pattern of the monthly mean climatology. Key Points: - First study estimating barrier layer thickness (BLT) in the Banda Sea using comprehensive observations - A quasi-permanent barrier layer exists in the Banda Sea with seasonal variation in occurrence and thickness - The intrusion of low saline waters and anticyclonic circulation are identified as the main mechanisms for creating and modulating the local BLT

Description: Key Points: - We reconstruct the temporal evolution of seawater isotope ratios of boron, strontium, lithium, and osmium over the last 65 million years - The evolution of seawater boron isotope ratio shows similarity to the evolution of strontium, lithium and osmium isotope ratios - Randomly drawn, smooth time series are provided for use in uncertainty propagation in calculation of palaeo pH The boron isotope ratio of seawater (δ11Bsw) is a parameter which must be known to reconstruct palaeo pH and CO2 from boron isotope measurements of marine carbonates. Beyond a few million years ago, δ11Bsw is likely to have been different to modern. Palaeo δ11Bsw can be estimated by simultaneously constraining the vertical gradients in foraminiferal δ11B (Δδ11B) and pH (ΔpH). A number of subtly different techniques have been used to estimate ΔpH in the past, all broadly based on assumptions about vertical gradients in oxygen, and/or carbon, or other carbonate system constraints. In this work we pull together existing data from previous studies, alongside a constraint on the rate of change of δ11Bsw from modeling. We combine this information in an overarching statistical framework called a Gaussian Process. The Gaussian Process technique allows us to bring together data and constraints on the rate of change in δ11Bsw to generate random plausible evolutions of δ11Bsw. We reconstruct δ11Bsw, and by extension palaeo pH, across the last 65Myr using this novel methodology. Reconstructed δ11Bsw is compared to other seawater isotope ratios, namely ,87/86 Sr, 187/188 Os , and δ7Li, which we also reconstruct with Gaussian Processes. Our method provides a template for incorporation of future δ11Bsw constraints, and a mechanism for propagation of uncertainty in δ11Bsw into future studies.

Description: Accurate reconstruction of seasonal atmospheric patterns of the past is essential for reliable prediction of how climate will evolve due to anthropogenic CO2 forcing. The Eocene ‘hot house’ climate, as the warmest epoch during the Cenozoic, is considered as a potential analogue for ‘high-CO2’ future climate scenarios. In this context, the reconstruction of variations in seasonality are as important as changes in mean annual conditions. Here we combine stable oxygen (δ18O) and dual clumped isotope (Δ47 + Δ48) measurements of a bivalve shell to determine sub-annual variations in sea surface temperatures and oceanic freshening in the Paris Basin during the Mid-Eocene Climate Optimum, 40 million years ago. Our reconstruction indicates to high mean annual temperatures with a small seasonal amplitude (33.3 °C ± 4.4 °C) and an enhanced fresh water input during the summer period. Our results implying a substantially warmer climate state with different hydrological conditions for Western Europe during the Eocene than previously suggested by proxy data or climate modelling.

Description: Climate change is threatening marine ecosystems on a global scale but particularly so in the Arctic. As a result of warming, species are shifting their distributions, altering marine communities and predator-prey interactions. This is known as the Atlantification of the Arctic. Warming may favor short-lived, opportunistic species such as cephalopods, marine mollusks that previously have been hypothesized to be winners in an ocean of change. To detect temporal regional trends in biodiversity, long-term annual surveys in hotspots of climate change are an unparalleled source of data. Here, we use 18 years of annual bottom trawl data (2005–2022) to analyse cephalopods in the western Barents Sea. More specifically, our research goals are to assess temporal trends in cephalopod fauna composition, abundance and biomass, and to relate these trends to climate change in the western Barents Sea. Main changes in cephalopod diversity and distribution occurred in mid-2000s and early 2010s, which corresponds with a period of warming in the Arctic since the late 1990s/early 2000s. Repeated increased occurrence of the boreal-subtropical cephalopods was recorded from 2005–2013 to 2014–2022. Moreover, the abundance of cephalopods in the area (in general and for most taxa) increased from 2005–2013 to 2014–2022. These observations suggest that the cephalopod community of the Barents Sea is subjected to Atlantification since the 2005–2013 period. This corresponds with previously reported evidence of the Atlantification in fishes and benthic invertebrates in the Barents Sea and benthic invertebrates. ‘Typical’ Arctic cephalopod species such as Bathypolypus spp., Gonatus fabricii and Rossia spp., however, are still much more abundant in the western Barents Sea compared to the deep-sea and the boreal-subtropical species. We also found indirect indications for body-size reduction in Bathypolypus spp. from 2005–2013 to 2014–2022. Overall, the temporal trends in the Barents Sea cephalopod fauna provide evidence for changing marine communities in the Arctic.

Description: FS Maria S Merian – MSM129/2 07.06.2024 – 06.07.2024 St. John’s (Kanada) – Reykjavik (Island) 2. Wochenbericht (10.06. – 17.06.2024)

Description: FS METEOR Expedition M201 VebVolc, 09.06. – 18.07.2024 | Reykjavik – Praia da Vitoria

Description: Technological developments have facilitated the collection of large amounts of imagery from isolated deep-sea ecosystems such as abyssal nodule fields. Application of imagery as a monitoring tool in these areas of interest for deep-sea exploitation is extremely valuable. However, in order to collect a comprehensive number of species observations, thousands of images need to be analysed, especially if a high diversity is combined with low abundances such is the case in the abyssal nodule fields. As the visual interpretation of large volumes of imagery and the manual extraction of quantitative information is time-consuming and error-prone, computational detection tools may play a key role to lessen this burden. Yet, there is still no established workflow for efficient marine image analysis using deep learning–based computer vision systems for the task of fauna detection and classification. Methods In this case study, a dataset of 2100 images from the deep-sea polymetallic nodule fields of the eastern Clarion-Clipperton Fracture zone from the SO268 expedition (2019) was selected to investigate the potential of machine learning–assisted marine image annotation workflows. The Machine Learning Assisted Image Annotation method (MAIA), provided by the BIIGLE system, was applied to different set-ups trained with manually annotated fauna data. The results computed with the different set-ups were compared to those obtained by trained marine biologists regarding accuracy (i.e. recall and precision) and time. Results Our results show that MAIA can be applied for a general object (i.e. species) detection with satisfactory accuracy (90.1% recall and 13.4% precision), when considered as one intermediate step in a comprehensive annotation workflow. We also investigated the performance for different volumes of training data, MAIA performance tuned for individual morphological groups and the impact of sediment coverage in the training data. Discussion We conclude that: a) steps must be taken to enable computer vision scientists to access more image data from the CCZ to improve the system’s performance and b) computational species detection in combination with a posteriori filtering by marine biologists has a higher efficiency than fully manual analyses.

Description: Nitric oxide (NO) is an intermediate of various microbial nitrogen cycle processes and the open ocean and coastal areas are generally a source of NO in the atmosphere. However, our knowledge about its distribution and the main production processes in coastal areas and estuaries is rudimentary at best. To this end, dissolved NO concentrations were measured for the first time in surface waters along the lower Elbe Estuary and Hamburg Port area in July 2021. The discrete surface water samples were analyzed using a chemiluminescence detection method. The NO concentrations ranged from below the limit of detection (9.1 × 10−12 mol L−1) to 17.7 × 10−12 mol L−1, averaging at 12.5 × 10−12 mol L−1 and were supersaturated in the surface layer of both the lower Elbe Estuary and the Hamburg Port area, indicating that the study site was a source of NO to the atmosphere during the study period. On the basis of a comprehensive comparison of NO concentrations with parallel nutrient, oxygen, and nitrous oxide concentration measurements, we conclude that the observed distribution of dissolved NO was most likely resulting from microbial nitrogen transformation processes, particularly nitrification in the coastal-brackish and limnic zones of the lower Elbe Estuary and nitrifier-denitrification in the Hamburg Port area.

Description: Age and longevity are key parameters for demography and life-history evolution of organisms. In clonal species, a widespread life history among animals, plants, macroalgae and fungi, the sexually produced offspring (genet) grows indeterminately by producing iterative modules, or ramets, and so obscure their age. Here we present a novel molecular clock based on the accumulation of fixed somatic genetic variation that segregates among ramets. Using a stochastic model, we demonstrate that the accumulation of fixed somatic genetic variation will approach linearity after a lag phase, and is determined by the mitotic mutation rate, without direct dependence on asexual generation time. The lag phase decreased with lower stem cell population size, number of founder cells for the formation of new modules, and the ratio of symmetric versus asymmetric cell divisions. We calibrated the somatic genetic clock on cultivated eelgrass Zostera marina genets (4 and 17 years respectively). In a global data set of 20 eelgrass populations, genet ages were up to 1,403 years. The somatic genetic clock is applicable to any multicellular clonal species where the number of founder cells is small, opening novel research avenues to study longevity and, hence, demography and population dynamics of clonal species.

Description: We investigate the origin of the equatorial Pacific cold sea surface temperature (SST) bias and its link to wind biases, local and remote, in the Kiel Climate Model (KCM). The cold bias is common in climate models participating in the 5 th and 6 th phases of the Coupled Model Intercomparison Project. In the coupled experiments with the KCM, the interannually varying NCEP/CFSR wind stress is prescribed over four spatial domains: globally, over the equatorial Pacific (EP), the northern Pacific (NP) and southern Pacific (SP). The corresponding EP SST bias is reduced by 100%, 52%, 12% and 23%, respectively. Thus, the EP SST bias is mainly attributed to the local wind bias, with small but not negligible contributions from the extratropical regions. Erroneous ocean circulation driven by overly strong winds cause the cold SST bias, while the surface-heat flux counteracts it. Extratropical Pacific SST biases contribute to the EP cold bias via the oceanic subtropical gyres, which is further enhanced by dynamical coupling in the equatorial region. The origin of the wind biases is examined by forcing the atmospheric component of the KCM in a stand-alone mode with observed SSTs and simulated SSTs from the coupled experiments. Wind biases over the EP, NP and SP regions originate in the atmosphere model. The cold EP SST bias substantially enhances the wind biases over all three regions, while the NP and SP SST biases support local amplification of the wind bias. This study suggests that improving surface-wind stress, at and off the equator, is a key to improve mean-state equatorial Pacific SST in climate models.

Description: Gas chimneys and gas clouds in the subsurface media are known as one of the indications of possible petroleum reservoirs. Investigations of their properties are mostly initiated by seismic attribute interpretation on reflection seismic data. However, due to the complexity of their behavior and their difficult interpretation of seismic attributes, state-of-the-art methods are mostly required to be applied on the seismic data to prevent any misinterpretation. This is mostly done through attribute integration and multi-attribute analysis. This research presents a study on seismic attributes and integration on several 2D seismic reflection lines from the Gorgan Plain. It is located in Northeast Iran, on the western border of the region’s well-known Kopeh-Dagh fold and thrust belt, and southeastern border of the South Caspian Basin. Hydrocarbon systems of the Gorgan Plain are poorly known and have not been widely studied, but according to preliminary investigations, this region has the potential for hydrocarbon occurrences. The aim of this study is to investigate presence and then delaminate the affected area of possible gas chimneys that are related to possible hydrocarbon reservoirs. Gas chimneys are assumed to be created due to the routes, mostly made by faults, that provoke light hydrocarbons components to migrate toward the surface. Preliminary interpretations of seismic reflection data in this study revealed that at least two gas chimneys occurred within the Gorgan Plain. As it was mentioned, since they are mostly due to the faulting above the hydrocarbon reservoir, gas chimney and heavy faulting might exhibit the same effects on the seismic data and then on its attributes, which are amplitude reduction and high damping on energies, distortion of the waveshape and seismic velocity reduction. Thus, care should be taken in separation of these two different geologic phenomena on seismic attributes. This also was done in this study through utilized integration of the most relevant seismic attributes such as Instantaneous-phase, Chaos, Variance and Remove-bias attributes. Based on the result of interpretations and according to the evolution of the basin and its structural reconstruction on other studies, gas chimneys of the Gorgan Plain, are in relation to the operation of fault zones in Cenozoic erathem in the region. These fault zones which cut the entire Cenozoic erathem, create the pathway for vertical migration of hydrocarbons through Cheleken formation (reservoir rock) and its overburden sedimentary sequences. In other words, operation of fault zones within Cenozoic sedimentary sequence, is the main reason for gas seepage in the Gorgan Plain, which is also shown in seismic data.

Description: Highlights • δ13C and δ18O profiles increase from exterior to interior until reaching a plateau. • Primary Layer δ13C reflects the δ13C of the Dissolved Inorganic Carbon. • In high pCO2 experiments, δ13C and δ18O closer to equilibrium fields. • Brachiopods grow according to an incremental growth model. Abstract Brachiopod shells are ubiquitous since the Early Cambrian up to now. As they secrete a shell made of low-magnesium calcite, more resistant to diagenesis than biocarbonates richer in Mg, their geochemical signatures are generally considered a powerful tool for paleo-environmental and paleo-climatic reconstructions. However, gaps in knowledge still remain on the underlying controls of the shell chemistry, in particular at a high spatial resolution. In this study, in situ oxygen and carbon isotope measurements by SIMS (Secondary Ion Mass Spectrometry) were performed in brachiopod shells of the cold-temperate water species Magellania venosa, constituted of a primary and a secondary layer. The individual specimens studied here grew under controlled conditions mimicking the natural environment and in experiments under low-pH (high pCO2) and high-temperature conditions. Transversal carbon and oxygen profiles showed a “brachiopod pattern” typical of extant two-layered brachiopods, with the primary layer depleted in 18O and 13C relative to equilibrium and the secondary layer showing a gradual increasing trend until reaching a near-equilibrium plateau. Overall, shells cultured at low pH were found to have δ18O and δ13C values closer to equilibrium when compared to shells from the control experiment. These near-equilibrium values may reflect a decrease in shell precipitation rate, leading to less kinetic effects, and/or a more rapid kinetics for the equilibration between DIC species and water. By close pairing of seawater δ18O and δ13C to that of shell microstructure, our study enables us to derive layer-specific C and O enrichment factors, which show the extent of pH and temperature effects superimposed on the seawater δ18O and DIC δ13C signal inherited. Finally, we show that during brachiopod shell growth, newly precipitated calcite is added to the calcite already existing, thus empirically validating the conceptual accretionary growth model proposed by Ackerly (1989).

Description: The Earth's magnetic field can provide reliable directional information, allowing migrating animals to orient themselves using a magnetic compass or estimate their position relative to a target using map-based orientation. Here we show for the first time that young, inexperienced herring (Clupea harengus, Ch) have a magnetic compass when they migrate hundreds of kilometres to their feeding grounds. In birds, such as the European robin (Erithacus rubecula), radical pair-based magnetoreception involving cryptochrome 4 (ErCRY4) was demonstrated; the molecular basis of magnetoreception in fish is still elusive. We show that cry4 expression in the eye of herring is upregulated during the migratory season, but not before, indicating a possible use for migration. The amino acid structure of herring ChCRY4 shows four tryptophans and a flavin adenine dinucleotide-binding site, a prerequisite for a magnetic receptor. Using homology modelling, we successfully reconstructed ChCRY4 of herring, DrCRY4 of zebrafish (Danio rerio) and StCRY4 of brown trout (Salmo trutta) and showed that ChCRY4, DrCRY4 and ErCRY4a, but not StCRY4, exhibit very comparable dynamic behaviour. The electron transfer could take place in ChCRY4 in a similar way to ErCRY4a. The combined behavioural, transcriptomic and simulation experiments provide evidence that CRY4 could act as a magnetoreceptor in Atlantic herring.

Description: The spectral composition of light is an important factor for the metabolism of photosynthetic organisms. Several blue light-regulated metabolic processes have already been identified in the industrially relevant microalga Monoraphidium braunii. However, little is known about the spectral impact on this species' growth, fatty acid (FA), and pigment composition. In this study, M. braunii was cultivated under different light spectra (white light: 400–700 nm, blue light: 400–550 nm, green light: 450–600 nm, and red light: 580–700 nm) at 25°C for 96 h. The growth was monitored daily. Additionally, the FA composition, and pigment concentration was analyzed after 96 h. The highest biomass production was observed upon white light and red light irradiation. However, green light also led to comparably high biomass production, fueling the scientific debate about the contribution of weakly absorbed light wavelengths to microalgal biomass production. All light spectra (white, blue, and green) that comprised blue-green light (450–550 nm) led to a higher degree of FA unsaturation and a greater concentration of all identified pigments than red light. These results further contribute to the growing understanding that blue-green light is an essential trigger for maximized pigment concentration and FA unsaturation in green microalgae.

Description: The addition of carbonate minerals to seawater through an artificial ocean alkalinity enhancement (OAE) process increases the concentrations of hydroxide, bicarbonate, and carbonate ions. This leads to changes in the pH and the buffering capacity of the seawater. Consequently, OAE could have relevant effects on marine organisms and in the speciation and concentration of trace metals that are essential for their physiology. During September and October 2021, a mesocosm experiment was carried out in the coastal waters of Gran Canaria (Spain), consisting on the controlled variation of total alkalinity (TA). Different concentrations of carbonate salts (NaHCO3 and Na2CO3) previously homogenized were added to each mesocosm to achieve an alkalinity gradient between Δ0 to Δ2400 µmol L−1. The lowest point of the gradient was 2400 µmol kg−1, being the natural alkalinity of the medium, and the highest point was 4800 µmol kg−1. Iron (Fe) speciation was monitored during this experiment to analyse total dissolved iron (TdFe, unfiltered samples), dissolved iron (dFe, filtered through a 0.2 µm pore size filter), soluble iron (sFe, filtered through a 0.02 µm pore size filter), dissolved labile iron (dFe′), iron-binding ligands (LFe), and their conditional stability constants () because of change due to OAE and the experimental conditions in each mesocosm. Observed iron concentrations were within the expected range for coastal waters, with no significant increases due to OAE. However, there were variations in Fe size fractionation during the experiment. This could potentially be due to chemical changes caused by OAE, but such an effect is masked by the stronger biological interactions. In terms of size fractionation, sFe was below 1.0 nmol L−1, dFe concentrations were within 0.5–4.0 nmol L−1, and TdFe was within 1.5–7.5 nmol L−1. Our results show that over 99 % of Fe was complexed, mainly by L1 and L2 ligands with ranging between 10.92 ± 0.11 and 12.68 ± 0.32, with LFe ranging from 1.51 ± 0.18 to 12.3 ± 1.8 nmol L−1. Our data on iron size fractionation, concentration, and iron-binding ligands substantiate that the introduction of sodium salts in this mesocosm experiment did not modify iron dynamics. As a consequence, phytoplankton remained unaffected by alterations in this crucial element.

Description: This article presents risk factors that are associated with the handling of unexploded ordnance (UXO) during explosive ordnance disposal (EOD) operations in German waters. The construction of offshore wind parks and the German immediate action program are expected to increase the number of EOD operations. Existing literature and guidelines do not offer a structured and reproducible framework for assessing EOD risk. To fill this gap, a network of EOD risk factors was developed by means of a literature review and validation via expert consultation. The study was scoped to “personnel and equipment at the EOD location” as the risk receptor and “undesired detonation” as the undesired event under investigation. Factors are subdivided into UXO factors that depend on the object that should be handled and factors that describe the object's surrounding environment. While the former can be researched by an EOD expert, the latter must be measured on site or acquired from a model. Each of these factors contributes to risk, some directly and others indirectly via other factors. The complexity of the resulting network, with its 33 factors, demonstrates the need for a reliable and reproducible model to quantify EOD risk. Its purpose is not to replace EOD experts but to aid them in their decision‐making process. Such a tool can provide valuable support for the high‐cost and high‐risk EOD operations.

Description: The mesopelagic or ocean twilight zone (OTZ) in the ocean contains huge numbers of fish in a relatively pristine environment and may therefore attract interest as a commercial fishery. In this study we evaluate in economic terms, the likely trade-offs between the different services provided by the mesopelagic layer in the Bay of Biscay and the societal benefits of its commercial exploitation. Benefits arise mainly from the likely use of this group of species as raw material for producing fishmeal and fish oil. Costs are derived from the loss in climate regulating and cultural, services, but also from the loss in the provisioning service of other commercial species. To do so we compare the current non-exploited status with a situation in where mesopelagic fishes are harvested at levels capable of producing the Maximum Sustainable Yield. Results suggest that if mesopelagic fishes are harvested, a mean value of 1.2 million Euro loss in a year will be created in the Bay of Biscay, although in a range between 42 million Euro loss and 48 Euro million benefits. This uncertainty comes, mainly, from the limited existing knowledge of the mesopelagic fishes’ biomass but also from the uncertainty on the biomass of the rest of the species of the studied ecosystem. The large range indicates that a better understanding of the mesopelagic ecosystem is needed, however, results also show that ecosystem services under no exploitation provided by the OTZ could be more valuable than the fishmeal and fish oil that potentially could be obtained from the fishes harvested in this sea layer.

Description: Infections by filamentous phages, which are usually nonlethal to the bacterial cells, influence bacterial fitness in various ways. While phage-encoded accessory genes, for example virulence genes, can be highly beneficial, the production of viral particles is energetically costly and often reduces bacterial growth. Consequently, if costs outweigh benefits, bacteria evolve resistance, which can shorten phage epidemics. Abiotic conditions are known to influence the net-fitness effect for infected bacteria. Their impact on the dynamics and trajectories of host resistance evolution, however, remains yet unknown. To address this, we experimentally evolved the bacterium Vibrio alginolyticus in the presence of a filamentous phage at three different salinity levels, that is (1) ambient, (2) 50% reduction and (3) fluctuations between reduced and ambient. In all three salinities, bacteria rapidly acquired resistance through super infection exclusion (SIE), whereby phage-infected cells acquired immunity at the cost of reduced growth. Over time, SIE was gradually replaced by evolutionary fitter surface receptor mutants (SRM). This replacement was significantly faster at ambient and fluctuating conditions compared with the low saline environment. Our experimentally parameterized mathematical model explains that suboptimal environmental conditions, in which bacterial growth is slower, slow down phage resistance evolution ultimately prolonging phage epidemics. Our results may explain the high prevalence of filamentous phages in natural environments where bacteria are frequently exposed to suboptimal conditions and constantly shifting selections regimes. Thus, our future ocean may favour the emergence of phage-born pathogenic bacteria and impose a greater risk for disease outbreaks, impacting not only marine animals but also humans.

Description: Open data, as an essential element in the sustainable development of the digital economy, is highly valued by many relevant sectors in the implementation process. However, most studies suppose that there are only data providers and users in the open data process and ignore the existence of data regulators. In order to establish long-term green supply relationships between multistakeholders, we hereby introduce data regulators and propose an evolutionary game model to observe the cooperation tendency of multistakeholders (data providers, users, and regulators). The newly proposed game model enables us to intensively study the trading behavior which can be realized as strategies and payoff functions of the data providers, users, and regulators. Besides, a replicator dynamic system is built to study evolutionary stable strategies of multistakeholders. In simulations, we investigate the evolution of the cooperation ratio as time progresses under different parameters, which is proved to be in agreement with our theoretical analysis. Furthermore, we explore the influence of the cost of data users to acquire data, the value of open data, the reward (penalty) from the regulators, and the data mining capability of data users to group strategies and uncover some regular patterns. Some meaningful results are also obtained through simulations, which can guide stakeholders to make better decisions in the future.

Description: The article evidences to what extent rights-based climate litigation is applied as a strategy to enhance the recognition and protection of climate-induced migrants. Adopting a deduc- tive approach and desk review, the study, illustrates how climate-induced migration has been addressed by International Human Rights Law, with some attention also paid to the growing application of the right to a safe climate and climate justice. The study highlights the duties of both States and private actors in tackling the emerging climate crisis under the human rights agenda. Relevant responsibilities are framed in particular within the scope of rights-based litiga- tion dealing with the topic. We present an analysis of litigation linked to climate-induced migration that was filed before distinct international, regional, and national jurisdictions and, in doing so, propose a chronology of cases—structured in three generations—of how population movements as a result of climate change have been discussed by judicial means. The first generation relates to cases that consider the issue from the perspective of protection—in both national, regional, and international jurisdictions. The second generation emerges within general climate litigation claims, involving commitments linked to the climate agenda. In addition to raising (forced) pop- ulation movements as one of the expected impacts of climate change, such cases frequently call upon a rights-based approach. The third generation encompasses rights-based cases cen- tred on climate-induced migrants per se. The strengths and limitations of rights-based litigation to respond to the topic are finally highlighted: we conclude that litigation remains a blunt but not unpromising tool to respond to climate-induced migration. Generic references to the risk of (forced) population movements largely prevail; nevertheless, strategic rights-based litigation can facilitate the visibility of climate-induced migrants to the international community, fostering the development of legal solutions in the longer term.

Description: The complex phase interactions of the two-phase flow are a key factor in understanding the flow pattern evolutional mechanisms, yet these complex flow behaviors have not been well understood. In this paper, we employ a series of gas–liquid two-phase flow multivariate fluctuation signals as observations and propose a novel interconnected ordinal pattern network to investigate the spatial coupling behaviors of the gas–liquid two-phase flow patterns. In addition, we use two network indices, which are the global subnetwork mutual information (⁠ ⁠) and the global subnetwork clustering coefficient (⁠ ⁠), to quantitatively measure the spatial coupling strength of different gas–liquid flow patterns. The gas–liquid two-phase flow pattern evolutionary behaviors are further characterized by calculating the two proposed coupling indices under different flow conditions. The proposed interconnected ordinal pattern network provides a novel tool for a deeper understanding of the evolutional mechanisms of the multi-phase flow system, and it can also be used to investigate the coupling behaviors of other complex systems with multiple observations.

Description: Global hydrological models (GHMs) are widely used to assess the impact of climate change on streamflow, floods, and hydrological droughts. For the 'model evaluation and impact attribution' part of the current round of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3a), modelling teams generated historical simulations based on observed climate and direct human forcings with updated model versions. Here we provide a comprehensive evaluation of daily and maximum annual discharge based on ISIMIP3a simulations from nine GHMs by comparing the simulations to observational data from 644 river gauge stations. We also assess low flows and the effects of different river routing schemes. We find that models can reproduce variability in daily and maximum annual discharge, but tend to overestimate both quantities, as well as low flows. Models perform better at stations in wetter areas and at lower elevations. Discharge routed with the river routing model CaMa-Flood can improve the performance of some models, but for others, variability is overestimated, leading to reduced model performance. This study indicates that areas for future model development include improving the simulation of processes in arid regions and cold dynamics at high elevations. We further suggest that studies attributing observed changes in discharge to historical climate change using the current model ensemble will be most meaningful in humid areas, at low elevations, and in places with a regular seasonal discharge as these are the regions where the underlying dynamics seem to be best represented.

Description: Urban agriculture, including peri-urban farming, can nourish around one billion city dwellers and provide multiple social, economic, and environmental benefits. However, these benefits depend on various factors and are debated. Therefore, we used machine learning to semi-automate a systematic review of the existing literature on urban agriculture. It started with around 76,000 records for initial screening based on a broad keyword search strategy. We applied the topic modeling approach to systematically understand various aspects of urban agriculture based on the full text of around 1450 relevant publications. Urban agriculture literature covers 14 topics, clustered into 11 themes related to urban agriculture forms, their multi-functionalities, and their underlying challenges. These forms are small-scale ground-based and building-integrated systems. The multifunctionalities include food, livelihoods, health benefits, social space, green infrastructure, biodiversity, and ecosystem services. Therefore, promoting urban agriculture requires accounting for its multi-functionalities, besides food provisioning,and encouraging efficient and sustainable practices.

Description: Having experienced low prices for about a decade, the European Union Emissions Trading System has been supplemented with the market stability reserve (MSR) that adjusts the supply of allowances to market outcomes. We critically review the literature assessing the performance of the MSR against several policy objectives. In doing so, we cover both conceptual aspects and quantitative assessments. We conclude by pointing out important policy implications and open issues for further research.

Description: Carbon prices in the EU emissions trading system are a key instrument driving Europe’s decarbonization. Between 2017 and 2021, they surged tenfold, exceeding €80 tCO2−1 and reshaping investment decisions across the electricity and industry sectors. What has driven this increase is an open question. While it coincided with two significant reforms tightening the cap (‘MSR reform’ and ‘Fit for 55’), we argue that a reduced supply of allowances alone cannot fully explain the price rise. A further crucial aspect is that actors must have become more farsighted as the reform signalled policymakers’ credible long-term commitment to climate targets. This is consistent with model results that show historic prices can be better explained with myopic actors, whereas explaining prices after the reforms requires actors to be farsighted. To underline the role of credibility, we test what would happen if a crisis undermines policy credibility such that actors become myopic again, demonstrating that carbon prices could plummet and endanger the energy transition.

Description: In diesem Positionspapier zur Neubewertung der DGE-Position zu veganer Ernährung werden neben neuen Daten zur Gesundheit auch die weiteren Zieldimensionen einer nachhaltigeren Ernährung (Umwelt, Tierwohl und Soziales) betrachtet. Zur Identifizierung relevanter Publikationen wurden ein Umbrella Review und ein ergänzendes systematisches Review durchgeführt sowie weitere Publikationen berücksichtigt. Die Betrachtung der Zieldimensionen Tierwohl und Soziales zeigt, dass die bisherigen Ansätze zur Bewertung der Auswirkung von Ernährungsweisen in diesem Zusammenhang noch nicht ausreichend etabliert sind und nicht umfassend angewendet werden. Daher werden nur die Zieldimensionen Gesundheit und Umwelt in die Position einbezogen. Gegenüber anderen Ernährungsweisen wurden bei einer veganen Ernährung potenzielle Vor- und Nachteile für die Gesundheit identifiziert. Für die gesunde erwachsene Allgemeinbevölkerung kann neben anderen Ernährungsweisen auch eine vegane Ernährung, unter der Voraussetzung der Einnahme eines Vitamin-B12- Präparats, einer ausgewogenen, gut geplanten Lebensmittelauswahl sowie einer bedarfsdeckenden Zufuhr der potenziell kritischen Nährstoffe (ggf. auch durch weitere Nährstoffpräparate), eine gesundheitsfördernde Ernährung darstellen. Für die vulnerablen Gruppen Kinder, Jugendliche, Schwangere, Stillende und Senior*innen kann die DGE aufgrund der weiterhin eingeschränkten Datenlage weder eine eindeutige Empfehlung für noch gegen eine vegane Ernährung aussprechen. Aufgrund des Risikos für potenzielle, teilweise irreversible Konsequenzen bei inadäquater Durchführung müssen für eine vegane Ernährung in vulnerablen Gruppen besonders fundierte Ernährungskompetenzen vorliegen. Eine Ernährungsberatung durch qualifizierte Fachkräfte ist daher für diese Gruppen dringend angeraten. Eine vegane Ernährung ist als äußerst umweltfreundlich anzusehen, sie stellt eine empfehlenswerte Maßnahme zur Verringerung der Umweltbelastungen des Ernährungssystems dar. Unter Berücksichtigung sowohl gesundheits- als auch umweltrelevanter Aspekte ist eine Ernährungsweise mit einer deutlichen Reduktion tierischer Lebensmittel zu empfehlen.

Description: The exchange of trace gases across the ocean/atmosphere interface, as well as the deposition of atmospheric pollutants and aerosols, are key processes linking the biogeochemical cycles and biological processes in the ocean with atmospheric chemistry and climate. Here we summarize our knowledge about the distributions of long-lived trace gases (CO2, CH4, N2O), short-lived trace gases, and pollutants (dimethyl sulfide (DMS), isoprene, halocarbons, NOx, SO2, O3, and others), and aerosols in the Indian Ocean. In general, dissolved trace gases show a pronounced temporal and spatial variability, which is caused by the variability of both physical processes (e.g., coastal upwelling) and biological productivity. The distributions of pollutants and aerosols and their depositions to the sea surface are mainly driven by the monsoon system and the variability of their land sources. Nitrogen and iron-containing aerosols can significantly affect biological production in the surface layer of the open Indian Ocean.

Description: Neomphaloidean gastropods are endemic to chemosynthesis-based ecosystems ranging from hot vents to organic falls, and their diversity and evolutionary history remain poorly understood. In the southwestern Pacific, deep-sea hydrothermal vents on back-arc basins and volcanic arcs are found in three geographically secluded regions: a western region around Manus Basin, an eastern region around North Fiji and Lau Basins, and the intermediate Woodlark Basin where active venting was confirmed only recently, on the 2019 R/V L’Atalante CHUBACARC expedition. Although various lineages of neomphaloidean snails have been detected, typically restricted to one of the three regions, some of these have remained without names. Here, we use integrative taxonomy to describe three of these species: the neomphalid Symmetromphalus mithril sp. nov. from Woodlark Basin and the peltospirids Symmetriapelta becki sp. nov. from the eastern region and Symmetriapelta radiata sp. nov. from Woodlark Basin. A combination of shell sculpture and radular characters allow the morphological separation of these new species from their described congeners. A molecular phylogeny reconstructed from 570 bp of the mitochondrial cytochrome c oxidase subunit I gene confirmed the placement of the three new species in their respective genera and the superfamily Neomphaloidea. The finding of these new gastropods, particularly the ones from the Woodlark Basin, provides insights and implications on the historical role of Woodlark as a dispersing centre, in addition to highlighting the uniqueness of the Woodlark faunal community.

Description: The Indian Ocean is an important conduit for the exchange of physical and biogeochemical properties through many distinct interbasin oceanic connections. The Indonesian archipelago provides a gappy pathway for warm tropical waters to enter the Indian Ocean from the Pacific. South of Australia, a complex circulation transports cooler subtropical waters from the Pacific while Indian Ocean waters from within the Leeuwin Current feed a series of currents along the southern Australian continental margin. Southern Ocean waters source both the deep and shallow overturning circulations into the Indian Ocean. The westward leakage of eddies spawned from the Agulhas Current off South Africa returns warm and salty Indian Ocean waters into the Atlantic and plays a significant role in the upper branch of the global meridional overturning circulation. This chapter discusses these pathways and highlights how they change with time and influence the circulation and properties of the Indian and global oceans.

Description: The cruise took place from 14.8.2005 (Akureyri) – 22.8.2005 (Akureyri) Research subject: ROV studies, mapping and sampling of the Tjörnes Offset (Storagrunn, Hollinn, Nafir) Chief Scientist: Prof. Dr. Colin W. Devey, IFM-GEOMAR, Kiel Number of Scientists: 10 Project: DFG De572/13-1 Fracture Zone

Description: Air-sea interaction in late boreal winter is studied over the extratropical North Atlantic (NA) during 1960–2020 by examining the relationship between sea-surface temperature (SST) and total turbulent heat flux (THF). The two quantities are positively correlated on interannual timescales over the central-midlatitude and subpolar NA, suggesting the atmosphere on average drives SST and THF variability is independent of SST. On decadal timescales and over the central-midlatitude NA the correlation is negative, suggesting ocean processes on average drive SST and THF variability is sensitive to SST. The correlation is positive over the subpolar NA. There, interannual and decadal THF variability is governed by the North Atlantic Oscillation (NAO). During the major late 20th and early 21st century SST increase in the subpolar NA diminishing oceanic heat loss associated with a weakening NAO was observed. This study suggests that the atmosphere is more sensitive to SST over the central-midlatitude than subpolar NA. Key Points: - Regional variation in the nature of air-sea interaction over the extratropical North Atlantic (NA) north of 35°N - Timescale dependence in relationship between sea-surface temperature (SST) and turbulent heat flux over the central-midlatitude NA - The atmosphere is more sensitive to SST variability over the central-midlatitude than subpolar NA

Description: The eastern boundary regions of the Atlantic and Pacific oceans host highly productive ecosystems. These upwelling systems play a key role in supporting marine biodiversity, local and global fisheries, and biogeochemical cycles. Consequently, it is of high interest to understand the processes driving these systems. This thesis focuses on one of these highly productive ecosystems - the tropical Angolan upwelling system (tAUS). Conditions in the tAUS undergo strong seasonal modulations, where many characteristics exhibit variability on semi-annual and annual time scales. The lowest sea surface temperature (SST), highest primary productivity, and lowest along-shore wind are found in austral winter during the main upwelling season. Interestingly, and in contrast to other upwelling systems, the productivity signal cannot be explained by local wind-driven upwelling. Possible forcing mechanisms of the productivity signal are connected to equatorial dynamics via the propagation of coastal trapped waves (CTWs). The tAUS is thus an ecosystem influenced by both remote and local processes. This thesis focuses on understanding the physical drivers of the seasonal and interannual variability in the tAUS, particularly in SST and primary productivity. The analyses conducted within this thesis are mostly based on observational datasets. Additionally, the results are compared with output of a regional ocean model. The observational data includes shipboard measurements as well as satellite products. The shipboard measurements comprise an extensive ocean turbulence dataset. This dataset provides, for the first time, insights into turbulent heat and nitrate fluxes in the tAUS. In the tAUS, waters are colder directly at the coast than further offshore. Both SST and the crossshore SST gradient exhibit a seasonal cycle. A seasonal mixed layer heat budget is calculated to identify atmospheric and oceanic causes for heat content variability. The results show that the seasonal cycle in SST is mainly controlled by surface heat fluxes and turbulent heat loss at the base of the mixed layer. The net surface heat flux warms the coastal ocean more strongly than the offshore region and thus acts to dampen cross-shore SST differences. Ocean turbulence data shows that turbulent mixing across the base of the mixed layer is an important cooling term. This turbulent cooling, being strongest in the shallow shelf regions, explains the observed negative cross-shore temperature gradient. The seasonal cycle of the cross-shore SST gradient exhibits semi-annual variability, likely linked to tidal mixing acting on changing background stratification associated with the passage of CTWs. The primary productivity in the tAUS peaks in late austral winter. Analyses of observational data and the output of a regional ocean model reveal that the seasonal productivity maximum is due to the combined effect of CTWs and elevated tidal mixing on the shelf. During austral winter, the passage of an upwelling CTW displaces the nitracline upward by more than 50 m. Thereby, nitrate-rich waters spread onto the shelf, where elevated vertical mixing causes a nitrate flux into the surface mixed layer. High-mode CTWs play an important role in the upward and onshore transport of nitrate-rich waters. The interannual variability of the productivity maximum in the tAUS is strongly correlated with the amplitude of the upwelling CTW. Consequently, it is of high interest to investigate dynamical factors controlling the characteristics of the CTW as their strength controls the amount of primary production in the tAUS. Regression analyses suggest that the timing and amplitude of the austral winter upwelling CTW in tAUS are influenced by variability in different regions. The timing of the CTW is mostly influenced by variability in the equatorial region and along the southern African coast. Here. weaker equatorial easterlies from April to July lead to a late arrival of the upwelling CTW. The amplitude of the CTW is influenced by variability in the eastern equatorial Atlantic and in the central South Atlantic, a region characterizing the strength of the South Atlantic anticyclone. A cooling in the eastern equatorial Atlantic four to three months before the arrival of the CTW causes stronger zonal winds, leading to a stronger austral winter upwelling CTW. In general, the results suggest that the timing and amplitude of the upwelling CTW in the tAUS during austral winter are predictable on seasonal time scales. Overall, this thesis enhances our understanding of the seasonal to interannaul dynamics in the tAUS. The results of this thesis show that CTWs, near-coastal mixing, and surface heat fluxes are essential processes to explain the seasonal variability of SST and productivity in the tAUS. A key result is the proposed mechanism explaining the austral winter productivity peak, based on the combined effect of CTWs and near-coastal mixing. This result not only advances process understanding in the tAUS but also suggests a potential predictability of productivity in the region.

Description: A stratigraphic complex composed of mass transport deposits (MTDs), where the gas occurrence allows for the formation of a gas chimney and pipe structure, is identified based on seismic interpretation in the QiongDongNan area of the northern South China Sea. During the Fifth Gas Hydrate Drilling Expedition of the Guangzhou Marine Geological Survey, this type of complex morphology that has close interaction with local gas hydrate (GH) distribution was eventually confirmed. A flow-reaction model is built to explore the spatial–temporal matching evolution process of massive GH reservoirs since 30 kyr before the present (BP). Five time snapshots, including 30, 20, 10, and 5 kyr BP, as well as the present, have been selected to exhibit key strata-evolving information. The results of in situ tensile estimation imply fracturing emergence occurs mostly at 5 kyr BP. Six other environmental scenarios and three cases of paleo-hydrate existence have been compared. The results almost coincide with field GH distribution below the bottom MTD from drilling reports, and state layer fracturing behaviors always feed and probably propagate in shallow sediments. It can be concluded that this complex system with 10% pre-existing hydrates results in the exact distribution and occurrence in local fine-grained silty clay layers adjacent to upper MTDs.

Description: Highlights • Statistically different gas geochemistry was observed in two adjacent springs. • About 74% of helium was contributed by the mantle. • Excess N2 relative to Ar was attributed to subducted materials and seawater mixing. • Magmatic CO2 has been largely removed by calcite precipitation in the reaction zone. • The residual CO2 may also be supplied by microbial oxidation of alkanes. Gas emissions from hydrothermal systems can serve as indicators of subsurface activity. In addition to gas sources, hydrothermal gas geochemistry is strongly influenced by secondary processes that occur during/after hydrothermal circulation. Here, we observed statistically significant differences in the geochemical characteristics (except for helium isotopes) of bubbling gases discharged from two adjacent vents in the Northern Luzon Arc. Helium (3He/4He = 4.25–7.09 Ra) in both vents was controlled by mixing between mantle and crustal components, where about 74% of helium was contributed by the mantle. Differences in N2/Ar ratios (∼ 300–330) of the two neighboring springs are attributed to subducted materials and seawater mixing (contributing ∼2.5% N2 and Ar), rather than phase separation in the reaction zone. Specifically, Ar was mainly supplied by atmospheric components that dissolved in the percolated seawater with only 8%–9% contributed by the excess radiogenic 40Ar. Excess N2 relative to Ar was mainly supplied by the decomposition of subducted materials (83%–92%) of the South China Sea plate beneath the Philippine Sea Plate. The Lutao gases showed low CO2 concentrations (0.07–22.2 mmol/mol), despite the high 3He/4He ratios indicating a significant contribution of magmatic components. Magmatic CO2 may have been largely consumed by the high Ca Lutao vent fluids via carbonate precipitation in the reaction zone. Alternatively, stable carbon isotope compositions (δ13C) indicate that Lutao CO2 may be supplied by microbial oxidation of alkanes (e.g., CH4 with concentrations of 14.6–173 mmol/mol in the samples), with fractionation factor ΔCO2–CH4 ranging from −15‰ to −25‰ and conversion rates of 〈10%. Up to 65% of the CO2 in the 2016 samples experienced secondary calcite precipitation in the discharge zone. Our results indicate that recycled subducted materials could potentially affect the geochemical characteristics of gases discharged from arc-volcanic systems. In addition, the influence of secondary processes needs to be considered before tracing the sources of hydrothermal fluids and/or gases, especially in shallow-water hydrothermal systems.

Description: Scientists are using a variety of geochemical, geophysical, and numerical methods to study offshore freshened groundwater and better understand its role in the global water cycle.

Description: The deep-sea water column below 200 m is a vast three-dimensional habitat with an enormous but largely unexplored biodiversity (Robison, 2009). Cephalopod mollusks are abundant in the deep sea and are important prey for many kinds of predators. Still, most deep-sea cephalopods have never been observed alive in their natural habitat and their reproductive biology remains poorly documented. In March of 2015, at a depth of 2566 m, we observed a female squid of an undescribed species but likely belonging to the Gonatidae, carrying few but exceptionally large eggs in her arms. This raises questions as to how these and other related animals reproduce in the deep sea, an environment that is generally characterized by darkness, low temperature, reduced oxygen, limited food availability, and low population densities. The authors were conducting dives with deep-sea robots (remotely operated vehicles or ROVs) equipped with cameras in the deep basins of the Gulf of California, to investigate how deep-sea fauna are distributed in relation to the extensive low-oxygen zones in the region (Gilly et al., 2013). The squid (Individual 1, Table 1) we observed with an ROV at 2566 m in the Gulf of California in 2015 was carrying 30–40 large eggs (average maximum diameter 11.2 mm, n = 5; measured eggs were 11.4, 10.4, 11.5, 11.7 and 11 mm maximum diameter) embedded in a small external egg sheet that did not extend beyond the arm tips. The size of the eggs was similar to those of two squid (Individuals 2 and 3, Table 1) that were observed close to the seafloor during earlier expeditions in the same region.

Description: Abstract Robust chronologies and time equivalent tephra markers are essential to better understand spatial palaeoenvironmental response to past abrupt climatic changes. Identification of well-dated and widely dispersed volcanic ash by tephra and cryptotephra (microscopic volcanic ash) provide time synchronous tie-points and strongly reduce chronological uncertainties. Here, we present the major, minor and trace element analyses of cryptotephra shards in the Dead Sea Deep Drilling sedimentary record (DSDDP 5017-1A) matching the Campanian Ignimbrite (CI). This geochemical identification expands the know dispersal range of the CI to the southeastern Mediterranean, over 2,300 km from the volcanic source. Due to the CI eruption occurring near-synchronous with North Atlantic ice surge of Heinrich Event 4 (HE4), this tephra provides insights into regional responses to large-scale climatic change in the Mediterranean. In the Dead Sea, the CI layer is associated with wetter climatic conditions. This contrasts with the contemporaneous occurrence of the CI deposition and dry conditions in the northern and western Mediterranean suggesting a possible climate time-transgressive expansion of HE4. Our finding underscores the temporal and spatial complexity of regional climate responses and emphasises the importance of tephra as a time marker for studying large-scale climatic changes verses regional variations.

Description: As a consequence of on-going global warming, the ocean is losing oxygen, which has implications not only in terms of marine resources management and food supply but also in terms of the potentially important feedback on the global carbon cycle and climate. Of particular scrutiny are the extended zones of already low levels of oxygen called the oxygen minimum zones (OMZs) embedded in the subsurface waters of the productive Eastern Boundary Upwelling Systems (EBUS). These OMZs are currently diversely simulated by state-of-the-art Earth System Models (ESM) hampering a reliable projection of ocean deoxygenation on marine ecosystem services in these regions. Here we focus on the most emblematic EBUS OMZs of the planet, that of the South Eastern Pacific (SEP), which is under the direct influence of the El Ni & ntilde;o Southern Oscillation (ENSO), the main climate mode on interannual timescales at global scale. We show that, despite the low consensus among ESM long-term projections of oxygen levels, the sensitivity of the depth of the upper margin (oxycline) of the SEP OMZ to El Ni & ntilde;o events in an ensemble of ESMs can be used as a predictor of its long-term trend, which establishes an emergent constraint for the SEP OMZ. Because the oxycline along the coast of Peru and Chile deepens during El Ni & ntilde;o events, the upper bound of the SEP OMZ is thus likely to deepen in the future climate, therefore oxygenating the SEP OMZ. This has implications not only for understanding the nitrogen and carbon cycles at global scale but also for designing adaptation strategies for regional upper-ocean ecosystem services. The upper bound of the southeast Pacific oxygen minimum zone deepens during El Ni & ntilde;o events across an ensemble of Earth system models and is therefore projected to likely contract in the future climate, according to an analysis of multiple Earth System Models.

Description: Low-level jets (LLJs), vertical profiles with a wind speed maxima in the lowest hundred meters of the troposphere, have multiple impacts in the Earth system, but a global present-day climatology based on contemporary data does not exist. We use the spatially and temporally complete data set from ERA5 reanalysis to compile a global climatology of LLJs for studying the formation mechanisms, characteristics, and trends during the period of 1992–2021. In the global mean, LLJs are detected 21% of the time with more cases over land (32%) than over the ocean (15%). We classified the LLJs into three categories: non-polar land (LLLJ), polar land (PLLJ), and coastal (CLLJ) LLJs. For LLLJ, the averaged frequency of occurrence is 20% and 75% of them are associated with a near-surface temperature inversion as a prerequisite for an inertial oscillation. PLLJs are also associated with a temperature inversion and occur even more frequently with 59% of the time. These are also the lowest and the strongest LLJs among the three categories. CLLJs are particularly frequent in some marine hotspots, situated along the west coast of continents, with neutral to unstable stratification close to the surfaces and a stably stratified layer aloft. We found distinct regional trends in both the frequency and intensity of LLJs over the past decades, which can have implications for the emission and transport of aerosols, and the transport of atmospheric moisture. Future studies could address changes in LLJs and the associated implications in more detail, based on the here released ERA5-based LLJ data. Key Points: - First global comprehensive low-level jet (LLJ) climatology using ERA5 - Polar LLJs are the strongest and most frequent among the detected types - Distinct past trends in regional LLJ frequency and intensity