ALBERT

Description: Highlights • Coupled geomicrobiology and geomechanics to investigate alterations in shales. • Microbial process can alter the mechanics, mineralogy, and microstructure of shales. • Biogeomechanical alterations reduced permeability by 93% and porosity by 38%. • Microfractures in shales can be sealed during biogeomechanical alterations. • Biogeomechanical alterations can enhance CO2 storage security and caprock integrity. Shales have been a major focus of the energy industry over the past few decades. Recently, there is a paradigm shift in the energy industry to low-carbon solutions, such as carbon capture and storage (CCS), to mitigate global warming caused by carbon footprint. The problem of long-term safe and efficient geological CO2 storage (GCS) and caprock integrity are some of the major challenges impeding large-scale CCS application. Here, we investigated how localized and bulk biogeomechanical alterations could potentially impact caprock integrity and CO2 storage in depleted shale reservoirs. We cultivated the shale core samples (containing both artificial-induced and pre-existing natural fractures) with a cultured microbial solution at specific temperature, time, and growth conditions. Subsequently, we obtain the properties of the fractured shale rock samples impacted by this microbial process. We investigate the impact of the mechanical responses due to the microbial process, on the long-term integrity and storage potentials of CO2 in shale reservoirs. Our results suggest that in Eagle Ford, Marcellus, and Niobrara shale formations, microbially-altered local and bulk mechanical properties can enhance the long-term caprock integrity and CO2 storage security by: (1.) Increasing the localized (+19% unconfined compressive strength, −20% Poisson’s ratio, +35% fracture toughness) and bulk (+50% unconfined compressive strength, −13% Poisson’s ratio) mechanical integrity; (2.) Decreasing permeability (−93%) and porosity (−38%); (3.) Altering the clay mineral content (−56%), calcite content (+21%), and morphology; (4.) Occluding microfractures; and (5.) Mitigating any potential leakage to the atmosphere through the caprock. This study considers the heterogeneity of shales, and provide valuable insights and viable assessment in solving the long-term GCS application in depleted hydrocarbon reservoirs.

Description: Highlights • Internal diffusion often controls the releases of flame retardants from microplastics. • Fick's law can describe the releases of additive flame retardants from microplastics. • Effects of temperature, plastic matrix, and particle size can be predicted by models. • Weathering of plastic matrix can greatly accelerate the releases of flame retardants. • Low fluxes of flame retardants released from microplastics pose no risk to ecosystem. The widely occurring debris of plastic materials, particularly microplastics, can be an important source of flame retardants, which are one of the main groups of chemicals added in the production of plastics from polymers. This review provides an overview on the use of flame retardants in plastic manufacturing, the kinetics of their releases from microplastics, the factors affecting their releases, and the potential environmental and ecosystem risk of the released flame retardants. The releases of flame retardants from microplastics typically involve three major steps: internal diffusion, mass transfer across the plastic-medium boundary layer, and diffusion in the environmental medium, while the overall mass transfer rate is commonly controlled by diffusion within the plastic matrix. The overall release rates of additive flame retardants from microplastics, which are dependent on the particle's geometry, can often be described by the Fick's Law. The physicochemical properties of flame retardant and plastic matrix, and ambient temperature all affect the release rate, which can be predicted with empirical and semi-empirical models. Weathering of microplastics, which reduces their particle sizes and likely disrupts their polymeric structures, can greatly accelerate the releases of flame retardants. Flame retardants could also be released directly from the microplastics ingested by aquatic organisms and seabirds, with physical and chemical digestion in the bodies significantly enhancing their release rates. Limited by the extremely slow diffusion in plastic matrices, the fluxes of flame retardants released from microplastics are very low, and are unlikely to pose significant risk to the ecosystem in general. More research is needed to characterize the mechanical, chemical, and biological processes that degrade microplastics and accelerate the releases of flame retardants and to model their release kinetics from microplastics, while efforts should also be made to develop environmentally benign flame retardants to ultimately minimize their risk to the environment and ecosystem.

Description: The ubiquitous use of microplastics and their release into the environment especially the water bodies by anthropogenic/industrial activities are the major resources for microplastic contamination. The widespread and often injudicious use of antimicrobial drugs or antibiotics in various sectors including human health and hygiene, agriculture, animal husbandry and food industries are leading to the release of antibiotics into the wastewater/sewage and other water bodies, particularly in urban setups and thus leads to the antimicrobial resistance (AMR) in the microbes. Microplastics are emerging as the hubs as well as effective carriers of these microbial pathogens beside their AMR-genes (ARGs) in marine, freshwater, sewage/wastewater, and urban river ecosystems. These drug resistant bacteria interact with microplastics forming synthetic plastispheres, the ideal niche for biofilm formations which in turn facilitates the transfer of ARGs via horizontal gene transfer and further escalates the occurrence and levels of AMR. Microplastic-associated AMR is an emerging threat for human health and healthcare besides being a challenge for the research community for effective management/address of this menace. In this review, we encompass the increasing prevalence of microplastics in environment, emphasizing mainly on water environments, how they act as centers and vectors of microbial pathogens with their associated bacterial assemblage compositions and ultimately lead to AMR. It further discusses the mechanistic insights on how microplastics act as hosts of biofilms (creating the plastisphere). We have also presented the modern toolbox used for microplastic-biofilm analyses. A review on potential strategies for addressing microplastic-associated AMR is given with recent success stories, challenges and future prospects.

Description: In the present work, an untargeted metabolomic approach based on ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC–HRMS) was performed for the discrimination of 25 accessions of white quinoa from main production zones of Peru. From the fingerprint analysis, a total of eighty-four metabolites were tentatively identified based on their accurate mass measurements and MS/MS data. Among them, forty-six compounds are reported here for the first time in C. quinoa (eight phenolics, one ecdysteroid, and thirty-seven saponins), twenty-four of them would correspond to new structures. Principal component analysis (PCA) and orthogonal partial least square discriminant analysis (OPLS-DA) were used to analyze the metabolomic data. As a result, the samples were distributed into two groups. The compounds contributing to the differences between these groups were identified by S-plot analysis.

Description: Microplastic particles are ubiquitous in the environment, from the air we breathe to the food we eat. The key question with respect to these particles is to what extent they cause risks for the environment and human health. There is no risk assessment framework that takes into account the multidimensionality of microplastic particles against the background of numerous natural particles, which together encompass an infinite combination of sizes, shapes, densities and chemical signatures. We review the current tenets in defining microplastic characteristics and effects, emphasizing advances in the analysis of the diversity of microplastic particles. We summarize the unique characteristics of microplastic compared with those of other environmental particles, the main mechanisms of microplastic particle effects and the relevant dose metrics for these effects. To characterize risks consistently, we propose how exposure and effect thresholds can be aligned and quantified using probability density functions describing microplastic particle diversity.

Description: Highlights • UAV-based thermal imaging allows precise mapping of diffusive thermal water discharge. • High tidal ranges affect fluid flow and promote larger thermal anomaly. • The La Jolla thermal anomaly is caused by a discharge of 330 ± 44 L s−1 of thermal water. • The La Jolla advective heat output (40.5 ± 5.2 MWt) can power a desalinization plant. The exploration of unexploited geothermal resources is required to encourage the use of renewable energy. This study focuses on La Jolla beach, Ensenada, Mexico. The beach hosts a thermal anomaly with temperatures of up to 52 °C at the surface and up to 93 °C at 20 cm depth. The objectives were to: map the thermal anomaly, understand the impact of tides, quantify the thermal water discharge rate and heat output, and discuss a direct use of the energy. The mapping was performed with Unmanned Aerial Vehicles equipped with optical and thermal cameras at two different dates. Additional temperature measurements were performed with a thermocouple, while the total fluid discharge was estimated from flow measurements. A comparison between the campaigns indicated that the highest surface temperature area was more than three times larger in 2019 than in 2018 (259 m2 vs. 69 m2). Such change was due to the tidal range and associated hydrostatic pressure variations. The total thermal water discharge is 330 ± 44 L s−1, which corresponds to an advective heat output of 40.5 ± 5.2 MWt. The use of this energy in a Multi-Effect Distillation desalinization plant can contribute to cover the shortage of freshwater in Ensenada.

Description: The Neolithic Revolution began approximately 10,000 years ago and is characterized by the ultimate, nearly complete transition from hunting and gathering to agricultural food production on land. The Neolithic Revolution is thought to have been catalyzed by a combination of local population pressure, cultural diffusion, property rights and climate change. We undertake a thought experiment that examines trends in these key hypothesized catalysts of the Neolithic Revolution and patterns of today to explore whether society could be on a path towards another paradigm shift in food production: away from hunting of wild fish towards a transition to mostly fish farming. We find similar environmental and cultural pressures have driven the rapid rise of aquaculture, during a period that has now been coined the Blue Revolution, providing impetus for such a transition in coming decades to centuries (as opposed to millennia). However, we also highlight the interacting and often mutually reinforcing impacts of 1) technological and scientific advancements, 2) environmental awareness and collective action and 3) globalization and trade influencing the trajectory and momentum of the Blue Revolution from patterns and processes of the Neolithic Revolution. We present two qualitative narratives that broadly fall within two future trajectories of seafood production: 1) a ubiquitous aquaculture transition and 2) commercial aquaculture and fisheries coexistence. Each narrative contains two sub-narratives based on differing management and regulatory strategies for aquaculture and fisheries. This scenarios approach aims to encourage logical, forward thinking, and innovative solutions to complex systems’ dynamics. Scenario-based thought experiments are useful to explore large scale questions, increase the accessibility to a wider readership, and ideally catalyze discussion around proactive governance mechanisms. We argue the future is not fixed and society now has greater foresight and capacity to choose the workable balance between fisheries and aquaculture that supports economic, environmental, cultural and social objectives through combined planning, policies, and management.

Description: For a long time, fungal pathogens have been a threat to the health and diet of humans. Consequently, antimycotic agents have been developed, which are called fungicides in agriculture and antifungals in medicine. Because fungi constantly develop resistance to established modes of action and because of the need for reducing the required use rates/doses, immense research efforts are still being undertaken to discover novel antimycotics. The research-based agrochemical industry has proven that these requirements can be fulfilled by a constant flow of novel fungicidal modes of action, the expansion of agronomical scope and applicability of existing fungicidal mode of action classes, and the design of resistance-breaking active ingredients in an established fungicidal mode of action class, if the molecular structure of the mutated fungal strain is known. Such strategies could be also useful for the discovery of novel antifungals.

Description: Glacial isostatic adjustment is largely governed by the rheological properties of the Earth's mantle. Large mass redistributions in the ocean–cryosphere system and the subsequent response of the viscoelastic Earth have led to dramatic sea level changes in the past. This process is ongoing, and in order to understand and predict current and future sea level changes, the knowledge of mantle properties such as viscosity is essential. In this study, we present a method to obtain estimates of mantle viscosities by the assimilation of relative sea level rates of change into a viscoelastic model of the lithosphere and mantle. We set up a particle filter with probabilistic resampling. In an identical twin experiment, we show that mantle viscosities can be recovered in a glacial isostatic adjustment model of a simple three-layer Earth structure consisting of an elastic lithosphere and two mantle layers of different viscosity. We investigate the ensemble behaviour on different parameters in the following three set-ups: (1) global observations data set since last glacial maximum with different ensemble initialisations and observation uncertainties, (2) regional observations from Fennoscandia or Laurentide/Greenland only, and (3) limiting the observation period to 10 ka until the present. We show that the recovery is successful in all cases if the target parameter values are properly sampled by the initial ensemble probability distribution. This even includes cases in which the target viscosity values are located far in the tail of the initial ensemble probability distribution. Experiments show that the method is successful if enough near-field observations are available. This makes it work best for a period after substantial deglaciation until the present when the number of sea level indicators is relatively high.

Description: Controlled-source electromagnetic methods have the potential to be used in reservoir monitoring problems due to their sensitivity to subsurface resistivity distribution. For example, time-lapse electromagnetic (EM) measurements can help to determine reservoir changes during enhanced oil recovery processes, such as water/steam injection or CO2 sequestration. Although metal infrastructure, such as pipelines and casings, can strongly influence EM data and mask the underlying geologic response, these effects have not previously been quantified for time-lapse surveys. We have analyzed the effects of well casings on time-lapse surface-to-surface EM measurements using 1D and 3D modeling. First, using a synthetic example of an onshore 1D hydrocarbon reservoir, we quantified the effect of single and multiple casings at several source and receiver locations. We found that time-lapse responses are significantly distorted when a source or receiver is located near a casing. Next, we approximated a hydrocarbon reservoir as a thin bounded resistive sheet. We developed a method of moments algorithm to calculate the respective secondary currents and charges on a well casing and resistive sheet combination and validated the electric fields these secondary sources generate against finite-element modeling. Finally, we calculated and explicitly demonstrated time-lapse amplitude changes in the well casing-thin-sheet interaction matrix, secondary currents, charges, and surface electric fields. Our 3D modeling results indicated that the conductive casing reduces the ability of the resistive sheet to impede current flow and distorts time-lapse responses. Therefore, one cannot fully eliminate casing effects by subtraction of time-lapse data and must fully incorporate such infrastructure into forward models for time-lapse EM inversion.

Description: Fresh Apostichopus japonicas (A. japonicas) are easy to autolyze through the actions of endogenous proteases under certain circumstances, further inducing a decline in A. japonicas product quality and business value. To solve this serious problem in the A. japonicas industry, we investigated the inhibition of phlorotannin extracts (PhTE) on the activities and structural changes of crude endogenous proteinase (CEP) from A. japonicas. The results of enzyme activity and SDS-PAGE indicated that PhTE could inhibit enzyme activity in a dose dependent manner. Analysis of multiple spectroscopic methods, scanning electron microscopy, and differential scanning calorimetry indicated that PhTE promoted the cross-linking and aggregation of CEP and increased the particle size of the enzyme, thus changing the structure of the enzyme protein and decreasing the thermostability of protease. In conclusion, PhTE might be an effective inhibitor on endogenous proteinase in A. japonicas, which opened up a new way to prevent the A. japonicas autolysis.

Description: Millions of tons of plastic waste are released into the marine environment every year. While they steadily accumulate, synthetic polymers provide a habitat for microorganisms. This denominated Plastisphere has been studied in detail over the past ten years. So have the enzymes responsible for microbial degradation, which are unfortunately lacking for most sorts of plastics. Therefore, the BMBF-funded project PLASTISEA is focusing on bioprospecting the marine treasure trove for novel plastic acting enzymes.

Description: Many of the socio-economic and environmental challenges of the 21st century like the growing energy and food demand, rising sea levels and temperatures put stress on marine ecosystems and coastal populations. This requires a significant strengthening of our monitoring capacities for processes in the water column, at the seafloor and in the subsurface. However, present-day seafloor instruments and the required infrastructure to operate these are expensive and inaccessible. We envision a future Internet of Underwater Things, composed of small and cheap but intelligent underwater nodes. Each node will be equipped with sensing, communication, and computing capabilities. Building on distributed event detection and cross-domain data fusion, such an Internet of Underwater Things will enable new applications. In this paper, we argue that to make this vision a reality, we need new methodologies for resource-efficient and distributed cross-domain data fusion. Resource-efficient, distributed neural networks will serve as data-analytics pipelines to derive highly aggregated patterns of interest from raw data. These will serve as (1) a common base in time and space for fusion of heterogeneous data, and (2) be sufficiently small to be transmitted efficiently in resource-constrained settings.

Description: Die Messung submariner Bodendeformationen an den Flanken von Inselvulkanen hilft dabei, ihre Stabilität und die Gefahr von Hangrutschungen einzuschätzen, ist aber inherent schwierig für Gebiete, die unter Wasser liegen. Wiederholte Seismik- oder Fächerecholot-Vermessungen können größere Gebiete abdecken, aber Auflösung und Lokalisierung sind bestimmten Grenzen unterworfen. Optische Daten andererseits sind besser aufgelöst, aber limitiert in ihrer räumlichen Abdeckung, und Meeresbodengeodäsie wiederum liefert nur punktuelle Information. In diesem Artikel schlagen wir vor, verschiedene Arten von Fernerkundungsdaten zusammenzubringen und auch mit bestehenden statischen und dynamischen Modellen zu verschneiden. Aufgrund ihrer verschiedenen Modalitäten, Unsicherheiten und Skalierungen ist dies jedoch schwierig und bedarf einer Fusion. Zusammen mit anderen Aspekten (Erdbeben, Strömungen etc.) sollen die fusionierten Daten und Modelle langfristig neue Einblicke in das dynamische System des sich verändernden Meeresbodens, die dafür verantwortlichen Faktoren sowie die Auswirkungen instabiler submariner Hänge auf andere Meeressysteme bieten.

Description: The European Union cap-and-trade emissions trading system (EU ETS) faces two challenges in the context of the European Green Deal. First, to meet the Paris temperature target, emissions in the energy and industrial sectors must fall to net-zero and then even become net-negative. Second, there is a concern that excessive CO2 price spikes and volatility on this path will jeopardize the political acceptance and support for emissions trading as a climate policy instrument. Conditional supply of carbon removal credits (CRCs) to support dynamic carbon price caps would make it possible to stabilize the market in the transition from positive to net-negative emissions trading while keeping the net-emissions path unchanged. CRCs would be assigned for carbon removal achieved for example with methods like Direct Air Carbon Capture and Storage or Bioenergy with Carbon Capture and Storage and would be used by companies under the EU ETS to compensate for their emissions. However, we suggest that there would be no direct exchange between emitting companies under the EU ETS and carbon removal companies, i.e., the demand and supply side of CRCs, during an initial phase. Instead, we suggest assigning an institutional mandate to for example a carbon central bank (CCB) to organize the supply of CRCs. Under this mandate, carbon removal would be procured, would be translated into a corresponding number of CRCs, and a fraction of it could be auctioned to the market at a later point in time, provided that market prices exceed a certain (dynamic) price cap.

Description: Algae synthesise structurally complex glycans to build a protective barrier, the extracellular matrix. One function of matrix glycans is to slow down microorganisms that try to enzymatically enter living algae and degrade and convert their organic carbon back to carbon dioxide. We propose that matrix glycans lock up carbon in the ocean by controlling degradation of organic carbon by bacteria and other microbes not only while algae are alive, but also after death. Data revised in this review shows accumulation of algal glycans in the ocean underscoring the challenge bacteria and other microbes face to breach the glycan barrier with carbohydrate active enzymes. Briefly we also update on methods required to certify the uncertain magnitude and unknown molecular causes of glycan-controlled carbon sequestration in a changing ocean.

Description: The depth of the Labrador Sea mixed layer during winter convection is a balance between atmospheric buoyancy loss and lateral buoyancy exchange, and is notoriously difficult to represent accurately in ocean and climate models. This study shows that lateral exchanges of heat and salt between the shelf and the interior are smaller in a regional coupled ocean–sea ice model at higher vertical resolution (75 levels compared with 50 levels), due in part to altered bathymetry along the Greenland shelf. Reduced lateral exchange results in a stronger stratification in the interior of the Labrador Sea, with stronger convection resistance which results in unrealistically shallow mixed layers. The westward fluxes of heat and salt associated with Irminger Water at Cape Farewell are 50 % and 33 % lower, respectively, with higher vertical resolution. Exchanges south of the Labrador Sea from the North Atlantic Current are also smaller, contributing to a reduction in salt and heat import into the Labrador Sea interior. When the high resolution model is forced with a stronger wintertime buoyancy loss at the ocean surface, this weakens the Labrador Sea stratification, allowing the forcing to break through the freshwater cap and increasing convection, bringing mixed layer depths back to observed values. A strong atmospheric forcing can therefore compensate for a reduction in lateral advection. The mixed layer depths, which are representative of convection and Labrador Sea water formation, will be the focus in this study. Therefore, this study suggests that convection and Labrador Sea Water formation is a complex interplay of surface and lateral fluxes, linked to stratification thresholds.

Description: The prediction of a spatial variable is of particular importance when analyzing spatial data. The main objective of this study is to evaluate and compare the performance of several prediction-based methods in spatial prediction through a simulation study. The studied methods include ordinary Kriging (OK), along with several neural network methods including Multi-Layer Perceptron network (MLP), Ensemble Neural Networks (ENN), and Radial Basis Function (RBF) network. We simulated several spatial datasets with three different scenarios due to changes in data stationarity and isotropy. The performance of methods was evaluated using the Root Mean Square Error (RMSE), Mean Absolute Error (MAE) and Concordance Correlation Coefficient (CCC) indexes. Although the results of the simulation study revealed that the performance of the neural network in spatial prediction is weaker than the Kriging method, but it can still be a good competitor for Kriging.

Description: Ongoing discoveries of terrestrial exoplanets and the desire to determine their habitability have created an increasing demand for studies of a wide range of climatic regimes and atmospheric circulations. These studies have, in turn, challenged our understanding of our own planet’s atmospheric dynamics and provided new frameworks with which we can further our understanding of planetary atmospheres. In this work, we use an idealized moist general circulation model in aquaplanet configuration to study the atmospheric circulation of terrestrial planets with high obliquities. With seasonally varying insolation forcing and a shallow slab ocean as a lower boundary, we emphasize seasonal phenomena that might not be captured in simulations with annual mean forcing and that might involve nonlinear behaviors. By progressively increasing obliquity, we explore the response of the large-scale atmospheric circulation to more extreme seasonal cycles and a reversed annual mean equator-to-pole insolation distribution, and its impact on the energy and water cycles. We show that for high obliquities, the large-scale atmospheric circulation and the meridional energy transport are dominated by seasonally reversing broad cross-equatorial Hadley cells that transport energy from the summer to the winter hemisphere and significantly mitigate temperature extremes. These overturning cells also play a major role in shaping the planet’s hydrological cycle, with the associated ascending branches and precipitation convergence zones becoming progressively broader and more poleward shifted into the summer hemisphere with higher obliquities. While not embedded within the Hadley cell ascending branches, the hot summer poles of high obliquity planets experience nonnegligible precipitation during and at the end of the warm season: during the summer, lower-level moist static energy maxima at the summer poles force locally enhanced convective activity. As temperatures rapidly drop at the end of the summer and convective activity decreases, the water-holding capacity of the atmosphere decreases and water vapor stored in the atmospheric column rapidly condenses out, extending the duration of the summer pole rainy season into the corresponding autumn. Our study reveals novel understanding of how atmospheric dynamics might influence a planet’s overall climate and its variability.

Description: The analysis of three extreme African dust outbreaks over the Iberian Peninsula (IP) shows that a double Rossby wave breaking (RWB) process in the polar jet (PJ) creates the conditions for dust storm formation over subtropical deserts in North Africa and the restructuring of upper-level air flows critical for the dust transport poleward after ablation. Two consecutive anticyclonic RWBs initiate over the IP and the adjacent Atlantic, the first commencing 10 days before dust reaches the IP and the second three to five days later. The first RWB becomes quasi-stationary over the eastern Mediterranean when the second RWB develops. In turn, the first RWB blocks downstream propagation of the second, which is amplified by energy reflection poleward from the first break causing vortex intensification and equatorward propagation over the Atlas as well as a strengthening and coupling of the subtropical jet (STJ) to circulations in the ITCZ. Zonal flows are blocked and sustained low-level northeasterlies/easterlies are induced across northwest Africa. The three events present substantial differences in the location and geometry of key upper- and low-level subsynoptic features that organize the dust storms over the Sahara following the second break. Dust lifted by either the cold outflow from convective downdrafts or by orographic gravity waves interacts with terrain-induced and larger scale circulations and is transported to the IP. The location of the cyclonic large scale signal from the second RWB to the west or over the Atlas and the blocking of zonal flows are key for the poleward dust transport.

Description: Strong‐motion recordings of the 2014 Mw 8.2 Iquique and 2015 Mw 8.3 Illapel, Chile, earthquakes were analyzed to determine rupture propagation and the location, timing, and strength of subevents that produce most of the high‐frequency (≥1 Hz) ground motions. A moving window,cross‐correlation analysis of recordings from a local dense array, band‐pass filtered at 1 Hz, directly shows that the Iquique earthquake ruptured to the southeast over a distance of about 60 km. Array analysis of lower frequency energy (0.03–0.1 Hz) indicates that it occurred updip of the high‐frequency rupture. A methodology was developed for inverting the envelopes of acceleration records (1–5 Hz) to map high‐frequency source factors on the rupture zone and was applied to the two earthquakes. Waveforms of Mw 6 earthquakes were used as empirical Green’s functions in the inversions. High‐frequency subevents within the two Mw 8 earthquakes were located at depths ranging from 25 to 55 km and mostly occurred downdip of the peak slip of these earthquakes. Fourier spectral ratios of the Iquique mainshock with respect to Mw 5–6 aftershocks were fit to determine their stress drops. The stress drops were roughly constant from Mw 5 to 8 at 10–20 MPa. A compound rupture model is described in which subevents occur in areas of spatially heterogeneous strength and stress on the rupture, and produce the high‐frequency radiated energy of the overall earthquake, but are not located in the areas of peak slip. The stress drop of the overall earthquake is shown to equal the root mean square stress drop of subevents averaged over the rupture area.

Description: The use of permanent arrays for continuous reservoir monitoring has become a reality in the past decades, with Ekofisk and Valhall being its flagships. One of the possibilities when such a solution is available is to passively record data while acquisitions with an active source are ongoing in nearby areas. These recordings might contain ultrafar-offset data (more than 30 km), which are hardly used in standard reservoir exploration and monitoring because they are mostly a combination of normal modes, deep reflections, and diving waves. We present data from the Valhall life-of-field seismic array, recorded while an active seismic survey was acquired at Ekofisk, in April 2014. Despite the lack of control on source firing time and position, analysis of the data indicates that the normal modes are remarkably clear, overcoming the ambient noise in the field. The normal modes can be well explained by a two-layer acoustic model, whereas a combination of diving waves and refracted waves can be fairly well reproduced with a regional 1D velocity model. We suggest a method to use far-offset recordings to monitor changes in shallow sediments between source and receivers, with and without a coherent seismic source in the area.

Description: Accurate and reliable biodiversity estimates of marine zooplankton are a prerequisite to understand how changes in diversity can affect whole ecosystems. Species identification in the deep sea is significantly impeded by high numbers of new species and decreasing numbers of taxonomic experts, hampering any assessment of biodiversity. We used in parallel morphological, genetic, and proteomic characteristics of specimens of calanoid copepods from the abyssal South Atlantic to test if proteomic fingerprinting can accelerate estimating biodiversity. We cross-validated the respective molecular discrimination methods with morphological identifications to establish COI and proteomic reference libraries, as they are a pre-requisite to assign taxonomic information to the identified molecular species clusters. Due to the high number of new species only 37% of the individuals could be assigned to species or genus level morphologically. COI sequencing was successful for 70% of the specimens analysed, while proteomic fingerprinting was successful for all specimens examined. Predicted species richness based on morphological and molecular methods was 42 morphospecies, 56 molecular operational taxonomic units (MOTUs) and 79 proteomic operational taxonomic units (POTUs), respectively. Species diversity was predicted based on proteomic profiles using hierarchical cluster analysis followed by application of the variance ratio criterion for identification of species clusters. It was comparable to species diversity calculated based on COI sequence distances. Less than 7% of specimens were misidentified by proteomic profiles when compared with COI derived MOTUs, indicating that unsupervised machine learning using solely proteomic data could be used for quickly assessing species diversity.

Description: Based on the numerical weather prediction model COSMO of Germany's national meteorological service (Deutscher Wetterdienst, DWD), regional reanalysis datasets have been developed with grid spacing of up to 2 km. This development started as a fundamental research activity within the Hans-Ertel-Centre for Weather Research (HErZ) at the University of Bonn and the University of Cologne. Today, COSMO reanalyses are an established product of the DWD and have been widely used in applications on European and national German level. Successful applications of COSMO reanalyses include renewable energy assessments as well as meteorological risk estimates. The COSMO reanalysis datasets are now publicly available and provide spatio-temporal consistent data of atmospheric parameters covering both near-surface conditions and vertical profiles. This article reviews the status of the COSMO reanalyses, including evaluation results and applications. In many studies, evaluation of the COSMO reanalyses point to an overall good quality and often an added value compared to different contemporary global reanalysis datasets. We further outline current plans for the further development and application of regional reanalyses in the HErZ research group Cologne/Bonn in collaboration with the DWD.

Description: The effective radiative forcing, which includes the instantaneous forcing plus adjustments from the atmosphere and surface, has emerged as the key metric of evaluating human and natural influence on the climate. We evaluate effective radiative forcing and adjustments in 17 contemporary climate models that are participating in the Coupled Model Intercomparison Project (CMIP6) and have contributed to the Radiative Forcing Model Intercomparison Project (RFMIP). Present-day (2014) global-mean anthropogenic forcing relative to pre-industrial (1850) levels from climate models stands at 2.00 (±0.23) W m−2, comprised of 1.81 (±0.09) W m−2 from CO2, 1.08 (± 0.21) W m−2 from other well-mixed greenhouse gases, −1.01 (± 0.23) W m−2 from aerosols and −0.09 (±0.13) W m−2 from land use change. Quoted uncertainties are 1 standard deviation across model best estimates, and 90 % confidence in the reported forcings, due to internal variability, is typically within 0.1 W m−2. The majority of the remaining 0.21 W m−2 is likely to be from ozone. In most cases, the largest contributors to the spread in effective radiative forcing (ERF) is from the instantaneous radiative forcing (IRF) and from cloud responses, particularly aerosol–cloud interactions to aerosol forcing. As determined in previous studies, cancellation of tropospheric and surface adjustments means that the stratospherically adjusted radiative forcing is approximately equal to ERF for greenhouse gas forcing but not for aerosols, and consequentially, not for the anthropogenic total. The spread of aerosol forcing ranges from −0.63 to −1.37 W m−2, exhibiting a less negative mean and narrower range compared to 10 CMIP5 models. The spread in 4×CO2 forcing has also narrowed in CMIP6 compared to 13 CMIP5 models. Aerosol forcing is uncorrelated with climate sensitivity. Therefore, there is no evidence to suggest that the increasing spread in climate sensitivity in CMIP6 models, particularly related to high-sensitivity models, is a consequence of a stronger negative present-day aerosol forcing and little evidence that modelling groups are systematically tuning climate sensitivity or aerosol forcing to recreate observed historical warming.

Description: We present the result of the third Marine Ice Sheet Intercomparison project, MISMIP+. MISMIP+ is intended to be a test of ice flow models which include fast sliding marine ice streams and floating ice shelves and in particular a treatment of viscous stress that is sufficient for buttressing, where upstream ice flow is restrained by a downstream ice shelf. A set of idealized experiments test the models in circumstances where buttressing contributes to a stable steady state, and where a reduction in that buttressing causes ice stream acceleration, thinning, and grounding line retreat. We find that the most important distinction between models in this particular type of simulation is in the treatment of sliding at the bed, with other distinctions – notably the difference between the simpler and more complete treatments of englacial stress, but also the differences between numerical methods – taking a secondary role.

Description: Varved lake sediments provide long climatic records with high temporal resolution and low associated age uncertainty. Robust and detailed comparison of well-dated and annually laminated sediment records is crucial for reconstructing abrupt and regionally time-transgressive changes as well as validation of spatial and temporal trajectories of past climatic changes. The VARved sediments DAtabase (VARDA) presented here is the first data compilation for varve chronologies and associated palaeoclimatic proxy records. The current version 1.0 allows detailed comparison of published varve records from 95 lakes. VARDA is freely accessible and was created to assess outputs from climate models with high-resolution terrestrial palaeoclimatic proxies. VARDA additionally provides a technical environment that enables to explore the database of varved lake sediments using a connected data-model and can generate a state-of-the-art graphic representation of multi-site comparison. This allows to reassess existing chronologies and tephra events to synchronize and compare even distant varved lake records. Furthermore, the present version of VARDA permits to explore varve thickness data. In this paper, we report in detail on the data mining and compilation strategies for the identification of varved lakes and assimilation of high-resolution chronologies as well as the technical infrastructure of the database. Additional paleoclimate proxy data will be provided in forthcoming updates. The VARDA graph-database and user interface can be accessed online at https://varve.gfz-potsdam.de, all datasets of version 1.0 are available at http://doi.org/10.5880/GFZ.4.3.2019.003 (Ramisch et al., 2019).

Description: Various observational estimates indicate growing mass loss at Antarctica's margins but also heavier precipitation across the continent. In the future, heavier precipitation fallen on Antarctica will counteract any stronger iceberg discharge and increased basal melting of floating ice shelves driven by a warming ocean. Here, we use from nine CMIP5 models future projections, ranging from strong mitigation efforts to business-as-usual, to run an ensemble of ice-sheet simulations. We test, how the precipitation boundary condition determines Antarctica's sea-level contribution. The spatial and temporal varying climate forcings drive ice-sheet simulations. Hence, our ensemble inherits all spatial and temporal climate patterns, which is in contrast to a spatial mean forcing. Regardless of the applied boundary condition and forcing, some areas will lose ice in the future, such as the glaciers from the West Antarctic Ice Sheet draining into the Amundsen Sea. In general the simulated ice-sheet thickness grows in a broad marginal strip, where incoming storms deliver topographically controlled precipitation. This strip shows the largest ice thickness differences between the applied precipitation boundary conditions too. On average Antarctica's ice mass shrinks for all future scenarios if the precipitation is scaled by the spatial temperature anomalies coming from the CMIP5 models. In this approach, we use the relative precipitation increment per degree warming as invariant scaling constant. In contrast, Antarctica gains mass in our simulations if we apply the simulated precipitation anomalies of the CMIP5 models directly. Here, the scaling factors show a distinct spatial pattern across Antarctica. Furthermore, the diagnosed mean scaling across all considered climate forcings is larger than the values deduced from ice cores. In general, the scaling is higher across the East Antarctic Ice Sheet, lower across the West Antarctic Ice Sheet, and lowest around the Siple Coast. The latter is located on the east side of the Ross Ice Shelf.

Description: A finely laminated lake sediment record with a basal age of 11,619 ± 603 years BP was retrieved from Lake Chatyr Kol (Kyrgyz Republic). Microfacies analysis reveals the presence of seasonal laminae (varves) from the sediment basis to ~ 360 ± 40 years BP. The Chatvd19 floating varve chronology covers the time span from 360 ± 40 years BP to the base and relies on replicate varve counts on overlapping petrographic thin sections with an uncertainty of ± 5 %. The uppermost non-varved interval was chronologically constrained by 210Pb and 137Cs γ-spectrometry and interpolation based on varve thickness measurements of adjacent varved intervals with an assumed uncertainty of 10 %. Six varve types were distinguished, are described in detail and show a changing predominance of clastic-organic, clastic-calcitic or -aragonitic, calcitic-clastic, organic-clastic and clastic-diatom varves throughout the Holocene. Variations in varve thickness and the number and composition of seasonal sublayers are attributed to 1) changes in the amount of summer or winter/spring precipitation affecting local runoff and erosion and/or to 2) evaporative conditions during summer. Radiocarbon dating of bulk organic matter, daphnia remains, aquatic plant remains and Ruppia maritima seeds reveal reservoir ages with a clear decreasing trend up core from ~ 6,150 years in the early Holocene, to ~ 3,000 years in the mid-Holocene, to ~ 1,000 years and less in the late Holocene and modern times. In contrast, two radiocarbon dates from terrestrial plant remains are in good agreement with the varve-based chronology.

Description: Whakaari/White Island is a partially submerged, offshore andesite island volcano, located at the northern end of the Taupō Volcanic Zone. Since the late 1960s, volcanic activity has alternated between quiescence, unrest, and eruption on short timescales. For this review we compiled extensive observational records, examined the rich scientific literature, and use newly acquired data, to understand the broad volcanic history and system dynamics. Based on recent bathymetry data, we propose a distinction exists between the Whakaari edifice and Te Paepae o Aotea/Volkner Rocks, which were previously considered to be part of the same edifice. Geochemical analyses of scoria samples from the island have been used to build a magma system model where dominantly andesitic-dacitic magma is periodically intruded by basalt. More dynamic processes are recorded in the hydrothermal system, where the location and activity of fumarolic features have been ephemeral and the crater lake has varied in scale over short time intervals. Eruptions of the dominantly andesitic magma have historically been small and range from phreatomagmatic through to magmatic, largely depositing ash and scoria to a restricted distance that is confined to the main crater floor. Phreatic eruptions are the most common eruption style, based on recently observed and monitored activity.

Description: Iron (Fe) is the fourth most abundant element in the earth’s crust and plays important roles in both biological and chemical processes. The redox reactivity of various Fe(II) forms has gained increasing attention over recent decades in the areas of (bio) geochemistry, environmental chemistry and engineering, and material sciences. The goal of this paper is to review these recent advances and the current state of knowledge of Fe(II) redox chemistry in the environment. Specifically, this comprehensive review focuses on the redox reactivity of four types of Fe(II) species including aqueous Fe(II), Fe(II) complexed with ligands, minerals bearing structural Fe(II), and sorbed Fe(II) on mineral oxide surfaces. The formation pathways, factors governing the reactivity, insights into potential mechanisms, reactivity comparison, and characterization techniques are discussed with reference to the most recent breakthroughs in this field where possible. We also cover the roles of these Fe(II) species in environmental applications of zerovalent iron, microbial processes, biogeochemical cycling of carbon and nutrients, and their abiotic oxidation related processes in natural and engineered systems.

Description: Intense, southward low-level winds are common in Nares Strait, between Ellesmere Island and northern Greenland. The steep topography along Nares Strait leads to channelling effects, resulting in an along-strait flow. This research study presents a 30-year climatology of the flow regime from simulations of the COSMO-CLM climate model. The simulations are available for the winter periods (November–April) 1987/88 to 2016/17, and thus, cover a period long enough to give robust long-term characteristics of Nares Strait. The horizontal resolution of 15 km is high enough to represent the complex terrain and the meteorological conditions realistically. The 30-year climatology shows that LLJs associated with gap flows are a climatological feature of Nares Strait. The maximum of the mean 10-m wind speed is around 12 m s-1 and is located at the southern exit of Smith Sound. The wind speed is strongly related to the pressure gradient. Single events reach wind speeds of 40 m s-1 in the daily mean. The LLJs are associated with gap flows within the narrowest parts of the strait under stably stratified conditions, with the main LLJ occurring at 100–250 m height. With increasing mountain Froude number, the LLJ wind speed and height increase. The frequency of strong wind events (〉20 m s-1 in the daily mean) for the 10 m wind shows a strong interannual variability with an average of 15 events per winter. Channelled winds have a strong impact on the formation of the North Water polynya.

Description: Highlights • Coupled microbiology and geomechanics to investigate alterations in shales. • Microbial process can alter the near-wellbore of shale gas reservoirs. • Microbial alterations of near-wellbore rock properties can weaken mechanical integrity. • Biogeomechanical alterations increased porosity (+42%) & permeability (+6430%). • Biogeomechanical alteration with other stimulation methods can improve gas recovery. Shale gas reservoirs, with typically ultra-low permeabilities, have been a major focus of hydrocarbon production over the past few decades. In this paper, we investigated how biogeomechanical alteration of near-wellbore properties could potentially impact hydrocarbon recovery from low-permeability reservoirs, using Wolfcamp shale and Niobrara shale formations. We first obtained the geomechanical properties using the scratch test method, in addition to the mineralogical, microstructural, and porosity and permeability measurements of the shale gas samples. Subsequently, we treated the core samples with a cultured microbial solution at distinct conditions. Further, we obtained the corresponding new geomechanical properties, in addition to the new mineralogical, microstructural, and porosity measurements of the samples impacted by the process. Finally, we showed the implications of the altered near-wellbore properties for hydrocarbon recovery from shale gas reservoirs. Our results suggest that in shale gas reservoirs, microbial-induced alterations of near well-bore properties could temporally reduce its mechanical integrity (Wolfcamp shale = −21% unconfined compressive strength, −42% scratch toughness; Niobrara shale = −24% unconfined compressive strength, −14% scratch toughness), increase porosity (+43%) and permeability (+6430%), and impact the microstructural and mineralogical properties. The near-wellbore biogeomechanical alterations could potentially improve hydrocarbon recovery by enhancing: (1.) the susceptibility for induced fractures to nucleate and propagate during reservoir-stimulation; (2.) flow pathways to improve hydrocarbon recovery.

Description: Both chemical and isotopic compositions of volcanic plumes are highly useful in evaluating the present status of active volcanoes. Monitoring their temporal changes can facilitate the forecasts of volcanic activity as well. In the present study, we developed a drone-borne automatic sampler for volcanic plumes in which an output signal from a sulfur dioxide (SO2) sensor triggered a pump to collect samples when its SO2 concentration exceeded a predefined threshold. First, we tested the automatic sampler while holding the device by hand at Iwo-yama volcano, Kirishima volcanic complex, Japan, where the fumaroles were accessible. Second, we fitted the sampler on a drone at Nakadake central cone, Aso volcano, Japan, where only the crater rim was accessible. In both sampling campaigns, good consistency in isotope ratios (2H/1H) of molecular hydrogen (H2) between samples collected by the automatic sampler and those collected directly into pre-evacuated flasks was obtained. Furthermore, by using the drone-borne sampler at Aso volcano, we obtained plume samples with higher concentrations of H2 and carbon dioxide than those taken directly into flasks at the crater rim. Our sampler can be utilized to collect volcanic plume samples for the determination of stable isotopic compositions in general by subsequent laboratory analysis and the remote establishment of fumarole outlet temperature based on the 2H/1H ratios of hydrogen, including their temporal changes.

Description: Volcaniclastic stratigraphy can be difficult to map and describe due to its complex nature. However, such stratigraphy preserves information about fluctuations in volcanic activity and sedimentation and is vital to understanding volcanic systems. Uncrewed aerial vehicle (UAV) based analysis of volcanic stratigraphy can enhance mapping and analysis, especially on vertical surfaces where outcrop exposure is greatest. Here we present a method for using small UAVs to produce vertical grain size and bedding measurement logs, or quantitative stratigraphic columns, of vertical volcaniclastic stratigraphy. We demonstrate the range of high-accuracy measurements and parameters that can be collected for building measurement logs using consumer grade UAVs through a case study in the Marysvale volcanic field where we collected 34,422 grain measurements from 21 individual units. The purpose of producing such measurement logs is to enhance lithofacies analysis through the use of large quantitative datasets and improve the reproducibility of data reporting. Whereas descriptions of volcaniclastic units such as those describing grading are often reported qualitatively, we describe methods for calculating numerical parameters for enhanced lithologic analysis including grain size, grading, clast to matrix ratios, and shape characteristics. The methods described in this paper can enhance field data acquisition, mapping, and quantitative analysis of volcaniclastic deposits and are applicable to a wide range of other geologic settings where coarse-grained clastic sedimentary deposits exist.

Description: Plankton is a massive and phylogenetically diverse group of thousands of prokaryotes, protists (unicellular eukaryotic organisms), and metazoans (multicellular eukaryotic organisms; Fig. 1). Plankton functional diversity is at the core of various ecological processes, including productivity, carbon cycling and sequestration, nutrient cycling (Falkowski 2012), interspecies interactions, and food web dynamics and structure (D'Alelio et al. 2016). Through these functions, plankton play a critical role in the health of the coastal and open ocean and provide essential ecosystem services. Yet, at present, our understanding of plankton dynamics is insufficient to project how climate change and other human-driven impacts affect the functional diversity of plankton. That limits our ability to predict how critical ecosystem services will change in the future and develop strategies to adapt to these changes.

Description: Mussel aquaculture is heavily reliant on wild mussel populations that supply juveniles (spat) for seeding farms. However, little is often known about parent populations, representing a risk for the sustainability of the industry. We used hydrodynamic back-tracking models to identify potential parental areas that provision green-lipped mussel (Perna canaliculus) spat across a range of settlement sites in New Zealand's largest aquaculture area. Median parental area varied considerably between 19 km2 for sites located in enclosed bays and a maximum of 〉1150 km2 for sites located in open bays. Median distance to parent populations ranged between 1.8 and 21.4 km, with a maximum larval dispersal estimated to be ca. 100 km. Small seasonal variations in parental area and dispersal distance were detected in some regions, whereas inter-annual variability was relatively minor. Regional connectivity between settlement and parental regions ranged between a minimum of 45% of larvae originating in the same parental region, to maximum retention rates of 99.9% for sites in enclosed bays, implying a considerable regional variation in the potential for self-seeding and exporting mussel larvae other areas. Our results also delineate areas that support spatfall by identifying likely locations for wild or farmed parental populations, and by establishing the spatial extent where mussel reproduction and larval development through to settlement take place. These dispersal and connectivity patterns are crucial to support management decisions for the conservation and restoration of parental populations, and other environmental constraints, such as water quality, which are necessary to ensure the sustainability of spat catching operations that enable shellfish farming.

Description: This article briefly outlines the geology of aquatic deposits in the Ma‘an desert, which consist of semi-consolidated gypsum layers intercalated by semi-consolidated sandstones, siltstones and mudstones with stromatolitic structures. They were deposited in a periodic river, called the Tawil River, and after that in a pond environment. The Tawil River is incised into the chalky limestone (Um Rijam Chert Limestone Formation, Eocene) and was filled later with cross-bedded sand. In the shallower parts, the river bed sediments dried out and mud cracks have been formed. Muddy deposits of the pond had been penetrated by plant roots, which traces are still quite clearly visible in some places. When the ponds dried out, salts started to precipitate forming crusts of gypsum and halides. Halides became washed away again by the next flood while gypsum remained in solid form. The outcrops are overlain by a recent soil covered by eroded chert fragments of the Um Rijam Chert Limestone Formation. The area has been influenced by tectonic events which can be made responsible for the preservation or disappearance of the river deposits. The Tawil River surrounding and the subsequent ponds had also served for ancient humans as a settlement ground and the hunting area.

Description: Aqueous sorption processes play an important role in, for example, pollutant binding to natural nanoparticles, colloid stability, separation and enrichment of components and remediation processes. In this article, which is a tribute to Hans Lyklema, models of localized (ad)sorption of molecules and ions from aqueous solution on homogeneous and heterogeneous nanoparticles are presented. The discussed models range from ideal monocomponent sorption on homogeneous (Langmuir) and heterogeneous sites, to multicomponent ideal sorption on homogeneous and heterogeneous sites, multicomponent multisite ion complexation with charge distribution (CD-MUSIC) and non-ideal competitive adsorption on heterogeneous sites (NICA). Attention is also paid to lateral interaction, site-induced aggregation, binding stoichiometry and multilayer formation. Electrical double layer models are discussed in relation to ion binding on impermeable and permeable nanoparticles. Insight in models that can describe sorption of molecules and ions on nanoparticles leads to awareness of the limitations of using simple models for complex systems and is needed for the selection and application of an appropriate model for a given system. This is relevant for all practical sorption processes and for a better understanding of the role of natural nanoparticles in the binding of nutrients and pollutants.

Description: Seismic techniques are the main monitoring tools for CO2 storage projects, especially in saline aquifers with good porosity. The majority of existing commercial and pilot CO2 injections have resulted in clear time-lapse seismic anomalies that can be used for leakage detection as well as refinement of the reservoir models to conform with the monitoring observations. Both tasks are legal requirements imposed on site operators. This paper revisits the rock-physics effects that may play an important role in the quantitative interpretation of seismic data. First, we briefly describe a standard approach to the rock-physics modeling of CO2 injections: Gassmann-type fluid substitution accounts for the presence of compressible CO2 in the pore space, and dissolution/precipitation of the minerals changes the pore volume. For many geologic conditions and injection scenarios, this approach is inadequate. For example, dissolution of the carbonate cement may weaken the rock frame, wave-induced fluid flow between CO2 patches can vary the magnitude of the seismic response significantly for the same saturation, the fluid itself might undergo change, and the seal might act as a sink for CO2. Hence, we critically review the effects of some recent advances in understanding CO2 behavior in the subsurface and associated rock-physics effects. Such a review should help researchers and practitioners navigate through the abundance of published work and design a rock-physics modeling workflow for their particular projects.

Description: These are the first animals to pass mutations found outside sex cells

Description: Varying culture methods are commonly used for eastern oyster, Crassostrea virginica, aquaculture in the Northeast United States. Vibrio vulnificus and V. parahaemolyticus, two human pathogenic bacteria species, accumulate in this edible, filter feeding shellfish. This study examined the use of two methods in an intertidal area (oysters cultured in trays and in bags on sediment) and two methods in a subtidal area (oysters cultured in trays and loose on the sediment) in Massachusetts over the growing season in 2015. Abundance of total V. vulnificus along with total and pathogenic (tdh+/trh+) V. parahaemolyticus were determined in oysters, sediment and water using real-time PCR. Temperature, salinity, turbidity and chlorophyll were continually measured every 15 min at each location. There were significantly higher abundances of total and pathogenic V. parahaemolyticus in on-bottom cultured oysters, while significantly higher abundances of V. vulnificus were identified in oysters from off-bottom culture in a subtidal location in Duxbury Bay, MA. In an intertidal location, Wellfleet Bay, MA, significantly higher abundances of total and tdh+ V. parahaemolyticus were found in off-bottom oysters, but significantly higher abundances of V. vulnificus and trh+ V. parahaemolyticus were found in on-bottom oysters. Spearman's correlation indicated that temperature is positively associated with concentrations of Vibrio spp. in oysters, water and sediment, but positive correlations between salinity and Vibrio spp. was also observed. Conversely, turbidity had a negative effect on Vibrio spp. concentrations in all sample types. There was no observed relationship inferred between chlorophyll and Vibrio spp. abundances in oysters, water or sediment.

Description: The product of frictional melting of geomaterials is termed “pseudotachylyte”. The name, first coined by Shand (1916), represents the visual similarity to the lava “tachylyte”, being a dark aphanitic rock with a glassy appearance. Pseudotachylytes have been referred to by many names since their first identification, including trap-shotten gneiss (Holland 1900), hyalomylonite (Masch et al. 1985) and frictionite (Maddock 1986), the latter of which is still occasionally used. Controversy remains as to the precise defining characteristics of pseudotachylytes (Magloughlin and Spray 1992; Rowe et al. 2005; Spray 2010) and...

Description: A central promise of cross-domain fusion (CDF) is the provision of a “bigger picture” that integrates different disciplines and may span very different levels of detail. We present a number of settings that call for this bigger picture, with a particular focus on how information from several domains can be made easily accessible and visualizable for different stakeholders. We propose harnessing an approach that is now well established in interactive maps, which we refer to as the “Google maps approach” (Google LLC, Mountain View, CA, USA), which combines effective filtering with intuitive user interaction. We expect this approach to be applicable to a range of CDF settings.

Description: Clastic dominant-type massive sulfide deposits are well preserved in Upper Devonian carbonaceous mudstones in the Macmillan Pass district (Yukon, Canada). The Macmillan Pass deposits have been considered to be type examples of sedimentary exhalative Zn-Pb mineralization, whereby sulfides precipitated when hydrothermal fluids were vented into a euxinic (H2S-bearing) water column. We propose a new mineralization model, documenting the mineralogical evolution of layered mineralization. We show that textures previously interpreted to form via depositional processes actually formed by subseafloor replacement of diagenetic barite. Mineral assemblages associated with barite dissolution in the layered mineralization include (1) barium carbonate phases (witherite, barytocalcite, and norsethite), which are intergrown with Zn-Pb sulfides and represent localized Ba mass transfer, and (2) barium feldspar (celsian, hyalophane) that is abundant in the mudstones surrounding the layered mineralization. The barium feldspar formed following transport of Ba in low-sulfate fluids on the margins of the subseafloor replacement system. This resulted in whole-rock Ba enrichments (up to 5 wt %) in mudstones 15 m below and above the layered mineralization. High Ba in these surrounding mudstones is coupled with decreasing K/Al ratios, indicative of secondary illite and kaolinite. The source(s) of fluids related to the diagenetic (barite, barytocalcite) and hydrothermal (ankerite) assemblages can be constrained using Sr isotopes. Whereas highly radiogenic 87Sr/86Sr values (〉0.714) in ankerite correspond with host-rock alteration within the vent complex, the overlying barite and barytocalcite preserve lower 87Sr/86Sr values (〈0.714), providing evidence of mixing between a radiogenic fluid (likely a formation water) and Late Devonian seawater. The complex mineralogy and paragenesis contained within the layered mineralization are linked to a protracted history of diagenetic and hydrothermal fluid events, all of which took place in and peripheral to a subseafloor replacement hydrothermal system.

Description: The representation of tropical precipitation is evaluated across three generations of models participating in phases 3, 5, and 6 of the Coupled Model Intercomparison Project (CMIP). Compared to state-of-the-art observations, improvements in tropical precipitation in the CMIP6 models are identified for some metrics, but we find no general improvement in tropical precipitation on different temporal and spatial scales. Our results indicate overall little changes across the CMIP phases for the summer monsoons, the double-ITCZ bias, and the diurnal cycle of tropical precipitation. We find a reduced amount of drizzle events in CMIP6, but tropical precipitation occurs still too frequently. Continuous improvements across the CMIP phases are identified for the number of consecutive dry days, for the representation of modes of variability, namely, the Madden–Julian oscillation and El Niño–Southern Oscillation, and for the trends in dry months in the twentieth century. The observed positive trend in extreme wet months is, however, not captured by any of the CMIP phases, which simulate negative trends for extremely wet months in the twentieth century. The regional biases are larger than a climate change signal one hopes to use the models to identify. Given the pace of climate change as compared to the pace of model improvements to simulate tropical precipitation, we question the past strategy of the development of the present class of global climate models as the mainstay of the scientific response to climate change. We suggest the exploration of alternative approaches such as high-resolution storm-resolving models that can offer better prospects to inform us about how tropical precipitation might change with anthropogenic warming.

Description: Highlights: • Temperature anomalies for the Mid-Holocene compared to preindustrial are significantly different in the low- and high-resolution versions of the atmospheric model ECHAM5 • For summer, shortwave cloud radiative forcing emerges as an important factor. • For boreal winter, differences are mainly related to circulation changes. • Anomaly differences are regionally as large as the mid-Holocene minus preindustrial temperature signals. Abstract: This study evaluates the dependence of simulated surface air temperatures on model resolution and orography for the mid-Holocene. Sensitivity experiments with the atmospheric general circulation model ECHAM5 are performed with low (∼3.75°, 19 vertical levels) and high (∼1.1°, 31 vertical levels) resolution. Results are compared to the respective preindustrial runs. It is found that the large-scale temperature anomalies for the mid-Holocene (compared to preindustrial) are significantly different in the low- and high-resolution versions. For boreal winter, differences are mainly related to circulation changes caused by the response to thermal forcing in conjunction with orographic resolution. For summer, shortwave cloud radiative forcing emerges as an important factor. The anomaly differences (low minus high resolution version) in the Northern Hemisphere are regionally as large as the anomalous mid-Holocene temperature signals. Furthermore, they depend on the applied surface boundary conditions. We conclude that the resolution matters for the Northern Hemisphere response in mid-Holocene simulations, which should be taken into account in model-model and data-model comparisons.

Description: Saccharina japonica is a commercially farmed seaweed of global importance. However, disease occurrence during different stages of cultivation can result in substantial economic losses. Identification of the causative agents of disease remains a significant bottleneck to the large scale cultivation of S. japonica. In this study, an aerobic heterotrophic, flagellated, rod-shaped Gram-negative bacterial strain X-8 was isolated from the bleaching diseased S. japonica sporelings. Pathogenecity of strain X-8 was tested by re-infection assay. The ultrastructural changes of infected S. japonica cells by strain X-8 indicated that chloroplasts were the first organelle responding to X-8 infection with deformed structure and later followed by fragmented nucleus. However, the ultra-structure of mitochondria and cell wall remained intact during the re-infection. Based on 16S rRNA gene sequence, morphological and biochemical characteristics, strain X-8 was designated as Pseudoalteromonas piscicida X-8. The pathogenicity of P. piscicida X-8 was identified by Koch's Postulate under laboratory conditions. Our results will not only help to establish a stable experimental model between the pathogenic bacteria and the host S. japonica to further elucidate the virulence mechanisms, but will also provide information for disease management to effectively prevent and mitigate the occurrence of bleaching disease of S. japonica at nursery stage.

Description: Recently, the aeromagnetic survey with Unmanned Aerial Vehicle (UAV) for mineral exploration has become ubiquitous. They can fly at a lower speed, lower altitude, need fewer crew members, and are cost-effective compared to traditional manned aeromagnetic. With the development of drones, magnetometers were also developed, which reduced the cost, weight, size, and energy consumption of these sensors. One of these sensors is the magneto-inductive magnetometer. This study investigates the integration of the UAV with a magneto-inductive sensor. We have performed an aeromagnetic survey along with six profiles and compared them with the terrestrial magnetic survey using a proton precision magnetometer. We show that the magneto-inductive sensor can sense Earth’s magnetic field’s change up to less than 60 nT. These results show the promising potential of using the UAV equipped with the magneto-inductive sensor to prospect the magnetic ore deposits.

Description: Highlights • UAV surveys can be used for evaluating long-term hillslope morphology evolution. • Successive landslides influence frequency distributions of topographic features. • Successive landslides gradually reduce slope gradient, roughness and local relief. • The slope gradient changes with elevation. Landslides are recognized as dominant geomorphic events of morphological evolution in most mountainous and hilly landscapes. However, the lack of multitemporal high-resolution topographic data has resulted in a lack of quantitative estimates of topographic changes influenced by successive landslides. Taking a typical hillslope with successive loess landslides in the Heifangtai loess tableland, China, as an example, we conducted four unmanned aerial system (UAS) surveys and created corresponding high-resolution digital elevation models (HRDEMs) and orthophotos. We found that multitemporal UAS surveys have become a powerful new approach for addressing local topographic changes and evolution over a relatively long time series. Moreover, landslides can leave persistent geomorphic imprints on hillslope topography. The frequency distributions of topographic indexes are significantly influenced by successive landslides. The mean slope gradient, roughness and local relief decreased with successive landslide occurrences, whereas the mean topographic wetness index (TWI) increased. However, the mean slope aspect was almost unchanged by successive landslides. Furthermore, analysis of the coefficient of variation demonstrates that the frequency distribution of the slope gradient becomes more dispersed with landslide occurrences, while the slope aspect and TWI become more concentrated. The slope gradient changes with elevation. More broadly, this study provides new insights into the prediction of the local topographic feature changes and morphology evolution trends caused by successive landslides.

Description: Highlights • Shale samples were exposed to slick water under the condition of 120 °C and 20 MPa within 30–90 days. • Microindentation was conducted to probe the distance-dependent, gradient alteration to shale mechanical properties. • The average rate of softening advancement was estimated as 0.13 mm/day. • The dissolution of carbonate minerals, pyrite oxidation and clay mineral osmotic swelling determine the shale softening. The shale softening behavior caused by hydrofracturing fluid is of great influence for the fracture conductivity and ultimate recovery of oil and gas from reservoir formations. This paper presents an experimental study on the characterization of a shale after being softened by the coupled thermo-hydro-mechanical-chemical (THMC) treatments that simulate the high-temperature and high-pressure rock-fluid interactions occurring in deep reservoirs during and after hydraulic fracturing. Microindentation tests were conducted to characterize the degradation degree and rate of mechanical properties of THMC-treated samples, and X-ray diffraction (XRD), scanning electron microscope (SEM), and micro-computed tomography (micro-CT) were carried out to analyze compositional and microstructural alterations of samples prior to and after THMC treatment. The results show that Young's modulus, hardness, and fracture toughness degrade significantly upon THMC treatment, and the average softening rate was estimated as 0.13 mm/day. The degradation of mechanical properties of the softened zones is primarily owing to the porous microstructure and crack propagation, resulting from the dissolution of carbonates, pyrite oxidation and the clay mineral osmotic swelling. These findings can provide a good insight of shale-fracturing fluid interactions, phenomenological behavior of shale softening that take place in deep reservoirs at elevated temperatures and pressures, and shed lights on the design, and operation of shale gas exploration.

Description: The recent and growing development and availability of unmanned aerial vehicles/systems (UAV, UAS, or “drones”) in volcanology has promoted a significant advance in volcanic surveillance of active volcanoes and in the characterization of volcanic landforms and hazards. However, in the tropics with heavy rainfall, deep volcanic soils and high relief, UAV surveying for volcanic geomorphology and volcanic hazards seems to be a relatively unexplored technique. Our aim is to present and promote innovative low-cost (〈$3000) UAV applications in volcanology to reduce costs and improve high-resolution quality (up to 8 cm/pixel) data acquisition in highly dynamic landscapes. Our results contribute to the state of the art of UAV applications in volcanic landforms in tropical developing countries where nearly half of the globally active volcanoes are located. Our findings prove that UAV's are a low-cost technique that can map large extensions of geomorphological features with accessibility limitations due to geological hazards and/or private property restrictions in short time. We surveyed four active volcanic sites in Costa Rica, Central America to illustrate potential applications of UAV mapping and geomorphological analysis of lava flows, debris avalanches, lahar deposits (debris flows) and biogeomorphic landscape changes due to forest succession. Analysis derived from the digital imagery captured by the UAV allowed to determine accurate volume calculations, surface roughness characteristics, morphometric quantifications, supervised surface classifications, and in combination with hydraulic modelling to assess hazards in urban planning. We discuss the utility, limitations, and future directions of low-cost UAV surveying in the geomorphological and geological analysis of tropical volcanic landforms and processes.

Description: Mount Agung (the highest volcano in Bali, Indonesia) began to erupt on November 21, 2017, after having been dormant for 53 years. More than 100,000 people were evacuated within the hazard zone between September 2017 (when the highest volcanic alert was issued) and early 2018. The eruptions continued until June 2019, accompanied by at least 110 explosions. During the eruptive crisis, the observation of the lava dome's emplacement was essential for mitigating the potential hazard. Details of the lava dome growth, including the volumetric changes and effusion rates, provide valuable information about potential eruption scenarios and lahar depositions. In this paper, the essential role of multi-temporal unmanned aerial vehicle (UAV) images in the monitoring of Mt. Agung's lava dome, and in determining the areas of potential lahar hazards during the crisis between 2017 and 2019 is described. A fixed-wing UAV was launched outside the hazard zone to photograph the lava dome on five occasions. Image enhancement, machine learning, and photogrammetry were combined to improve image quality, remove point clouds outliers, and generate digital terrain models (DTMs) and orthoimages. The analysis of the obtained DTMs and orthoimages resulted in qualitative and quantitative data highlighting the changes inside the crater and on the surrounding slopes. These results reveal that, from November 25 to December 16, 2017, the lava dome grew vertically by 126 m and reached a volume of 26.86 ± 0.64 × 106 m3. In addition, its surface experienced a maximal uplift of approximately 52 m until July 2019 with the emergence of a new dome with a volume estimated at 9.52 ± 0.086 × 106 m3. The difference between the DTMs of 2017 and 2019 reveals the total volume of erupted material (886,100 ± 8000 m3) that was deposited on the surrounding slopes. According to the lahar inundation simulation, the deposited material may cause dangerous lahars in 21 drainages, which extend in the north (N), north-east (N-E), south (S), south-east (S-E), and south-west (S-W) sectors of the volcano. This paper presents the use of UAV remote sensing for the production of high-spatial resolution DTMs, which can be used to both observe the emplacement of a lava dome, and to identify areas with potential lahar risk during a volcano crisis.

Description: Highlights • A new approach using UAS to map and classify volcanic deposits is described. • Tephra and lava are distinguished by their roughness and solar heating rate. • Solar heating rate decreases as lava transitions from pāhoehoe to ʻaʻā. • We compare manual and machine learning classification methods. The deposits from volcanic eruptions represent the record of activity at a volcano. Identification, classification, and interpretation of these deposits are crucial to the understanding of volcanic processes and assessing hazards. However, deposits often cover large areas and can be difficult or dangerous to access, making field mapping hazardous and time-consuming. Remote sensing techniques are often used to map and identify the deposits of volcanic eruptions, though these techniques present their own trade-offs in terms of image resolution, wavelength, and observation frequency. Here, we present a new approach for mapping and classifying volcanic deposits using a multi-sensor unoccupied aerial system (UAS) and demonstrate its application on lava and tephra deposits associated with the 2018 eruption of Sierra Negra volcano (Galápagos Archipelago, Ecuador). We surveyed the study area and collected visible and thermal infrared (TIR) images. We used structure-from-motion photogrammetry to create a digital elevation model (DEM) from the visual images and calculated the solar heating rate of the surface from temperature maps based on the TIR images. We find that the solar heating rate is highest for tephra deposits and lowest for ʻaʻā lava, with pāhoehoe lava having intermediate values. This is consistent with the solar heating rate correlating to the density and particle size of the surface. The solar heating rate for the lava flow also decreases with increasing distance from the vent, consistent with an increase in density as the lava degasses. We combined the surface roughness (calculated from the DEM) and the solar heating rate of the surface to remotely classify tephra deposits and different lava morphologies. We applied both supervised and unsupervised machine learning algorithms. A supervised classification method can replicate the manual classification while the unsupervised method can identify major surface units with no ground truth information. These methods allow for remote mapping and classification at high spatial resolution (〈 1 m) of a variety of volcanic deposits, with potential for application to deposits from other processes (e.g., fluvial, glacial) and deposits on other planetary bodies.

Description: How do people’s perceptions about when they work affect their intrinsic motivation? We find that working during non-standard work time (weekends/holidays) versus standard work time (Monday-Friday, 9-to-5) undermines people’s intrinsic motivation for their professional and academic pursuits. Working during non-standard work time decreases intrinsic motivation by causing people to consider better uses of their time. That is, people generate more upward counterfactual thoughts, which mediates the effect of work time on reduced intrinsic motivation. As a causal test of this process, increasing consideration of upward counterfactuals during standard work time reduces intrinsic motivation, whereas decreasing consideration of upward counterfactuals during non-standard work time helps employees and students maintain intrinsic motivation for their professional and academic pursuits. Overall, we identify a novel determinant of intrinsic motivation and address a real challenge many people face: How changing work schedules affect interest and enjoyment of work, with important consequences for work outcomes.

Description: Seagrasses are complex benthic coastal ecosystems that play a crucial role in organic matter cycling and carbon sequestration. However, little is known about how seagrasses influence the structure and carbon utilization potential of benthic bacterial communities. This study examined the bacterial communities in monospecific and mixed meadows of seagrasses and compared with bulk (unvegetated) sediments from Chilika, a brackish water coastal lagoon of India. High-throughput sequencing of 16S rRNA genes revealed a vegetation effect in terms of differences in benthic bacterial community diversity, composition, and abundances in comparison with bulk sediments. Desulfobacterales, Chromatiales, Enterobacteriales, Clostridiales, Vibrionales, and Acidimicrobiales were major taxa that contributed to differences between seagrass and bulk sediments. Seagrasses supported ∼5.94 fold higher bacterial abundances than the bulk due to rich organic carbon stock in their sediments. Co-occurrence network demonstrated much stronger potential interactions and connectedness in seagrass bacterial communities compared to bulk. Chromatiales and Acidimicrobiales were identified as the top two keystone taxa in seagrass bacterial communities, whereas, Dehalococcoidales and Rhizobiales were in bulk communities. Seagrasses and local environmental factors, namely, water depth, water pH, sediment salinity, redox potential, total organic carbon, available nitrogen, sediment texture, sediment pH, and sediment core depth were the major drivers of benthic bacterial community composition. Carbon metabolic profiling revealed that heterotrophic bacteria in seagrass sediments were much more metabolically diverse and active than bulk. The utilization of carbon substrate guilds, namely, amino acids, amines, carboxylic acids, carbohydrates, polymers, and phenolic compounds was enhanced in seagrass sediments. Metabolic mapping predicted higher prevalence of sulfate-reducer and N2 fixation metabolic functions in seagrass sediments. Overall, this study showed that seagrasses control benthic bacterial community composition and diversity, enhance heterotrophic carbon substrate utilization, and play crucial roles in organic matter cycling including degradation of hydrocarbon and xenobiotics in coastal sediments.

Description: The total cultivable microbiota of the ice-stored European sea bass (Dicentrarchus labrax), the most important commercial fish species of the Mediterranean aquaculture, was determined using 16S rRNA gene sequence analysis. High Resolution Melting (HRM) curve profiles and sequencing analysis (V3–V4 region of the 16S rRNA gene) were used respectively for the differentiation and identification of the collected isolates from six time intervals (day 0, 4, 8, 12, 14 and 16) while fish were stored in ice. HRM analysis differentiated the unknown microbiota in ten groups (208 isolates) and in two single isolates based on their HRM curve profiles. The isolates with HRM profiles which were 〉91% similar within each group were found to belong to the same species using sequencing analysis. Thus, the ten groups consist of representatives of Psychrobacter glacincola, Ps. alimentarius, Ps. cryohalolentis, Ps. maritimus, Ps. fozii, Pseudomonas sp., Paeniglutamicibacter sp., Carnobacterium sp., Leucobacter aridicolis and Bacillus thuringiensis. Based on this approach, Ps. cryohalolentis was found to be the most dominant phylotype at the beginning of fish shelf-life compared to other species. The abundance of this bacterium decreased throughout storage, while Ps. glacincola increased and dominated at the time of the sensory minimum acceptability (day 14) and rejection (day 16). To conclude, HRM could be used for the rapid determination of sea bass microbiota, using the representatives of each group as reference bacterial strains, in order for scientists to solve rapidly stakeholders problems related with microbial quality or safety of fish.

Description: Ringed seals (Pusa hispida) are slowly recovering in the eastern and northern parts of the Baltic Sea after years of hunting pressure and contaminant exposure. Still, consequences of anthropogenic activities such as contaminant exposure and increasing temperatures are stressors that continue to have deleterious effects on their habitat and health. Transcription profiles of seven health-related genes involved in xenobiotic metabolism, endocrine disruption and stress were evaluated in blood, blubber, and liver of Baltic ringed seals in a multi-tissue approach. Selected persistent organic pollutants and total mercury concentrations were measured in blubber and liver, and muscle and liver of these animals, respectively. Concentrations of contaminants varied across tissues on a lipid weight basis but not with sex. mRNA transcript levels for all seven target genes did not vary between sexes or age classes. Transcript levels of thyroid hormone receptor alpha (TRα), retinoic acid receptor alpha (RARα) and heat shock protein 70 (HSP70) correlated with levels of persistent organic pollutants. TRα transcript levels also correlated positively with mercury concentrations in the liver. Of the three tissues assessed in this multi-tissue approach, blubber showed highest transcription levels of aryl hydrocarbon receptor nuclear translocator (ARNT), thyroid stimulating hormone receptor beta (TSHβ), oestrogen receptor alpha (ESR1) and peroxisome proliferator activated receptor alpha (PPARα). The wide range of genes expressed highlights the value of minimally invasive sampling (e.g. biopsies) for assessing health endpoints in free-ranging marine wildlife and the importance of identifying optimal matrices for targeted gene expression studies. This gene transcript profile study has provided baseline information on transcript levels of biomarkers for early on-set health effects in ringed seals and will be a useful guide to assess the impacts of environmental change in Baltic pinnipeds for conservation and management.

Description: Controlled-source electromagnetics (CSEM) can be used to image subsurface resistivity and add value in petroleum exploration. However, the application of CSEM methods can be particularly challenging in mature oil and gas fields, where the presence of steel casings and complex seabed infrastructure may influence electromagnetic (EM) fields. The effect of this metal infrastructure can be modeled using the method of moments (MoM), which has previously been demonstrated to be effective in simple situations. We have now developed a methodology for modeling the EM response of complex pipeline geometry using MoM, and we validate our approach numerically and experimentally; the difference between finite-element and MoM modeling is less than 3%, whereas the difference between experimental data and MoM results is less than 30%. We further develop a fast and efficient approach to model the EM response of horizontal pipeline infrastructure. First, we create individual pipe sections of custom shape; when assembled, these sections are used to construct the entire pipeline system. We then identify “precise” and “approximate” zones based on how accurately we need to perform the calculations. We find that the electric field values in the approximate zone can be calculated accurately and quickly using previously saved table values, and therefore achieve a considerable reduction in computational requirements. Finally, we apply our methodology to a real situation of a 60 km horizontal seabed pipeline and find that the electric field distortion can be calculated rapidly and efficiently with our custom-built algorithm.

Description: Despite the well-known limitations of linear stability theory in describing nonlinear and turbulent flows, it has been found to accurately capture the transitions between certain nonlinear flow behavior. Specifically, the transition in heat flux scaling in rotating convective flows can be well predicted by applying a linear stability analysis to simple profiles of a convective boundary layer. This fact motivates the present study of the linear mechanisms involved in the stability properties of simple convective setups subject to rotation. We look at an idealized two-layer setup and gradually add complexity by including rotation, a bounded domain, and viscosity. The two-layer setup has the advantage of allowing for the use of wave interaction theory, traditionally applied to understand stratified and homogeneous shear flow instabilities, in order to quantify the various physical mechanisms leading to the growth of convective instabilities. We quantitatively show that the physical mechanisms involved in the stabilization of convection by rotation take two different forms acting within the stratified interfacial region, and in the homogeneous mixed layers. The latter of these we associate with the tendency of a rotating flow to develop Taylor columns (TCs). This TC mechanism can lead to both a stabilization or destabilization of the instability and varies depending on the parameters of the problem. A simple criterion is found for classifying the influence of these physical mechanisms.

Description: Highlights • Our data split method handles spatial autocorrelation and imposes prediction fairness. • The sets impose fair algorithms with similar difficulty in all machine learning steps. • Kriging variance is a surrogate of spatial prediction difficulty. • The resulting training and test sets are compatible with any machine learning model. Machine learning supports prediction and inference in multivariate and complex datasets where observations are spatially related to one another. Frequently, these datasets depict spatial autocorrelation that violates the assumption of identically and independently distributed data. Overlooking this correlation result in over-optimistic models that fail to account for the geographical configuration of data. Furthermore, although different data split methods account for spatial autocorrelation, these methods are inflexible, and the parameter training and hyperparameter tuning of the machine learning model is set with a different prediction difficulty than the planned real-world use of the model. In other words, it is an unfair training-testing process. We present a novel method that considers spatial autocorrelation and planned real-world use of the spatial prediction model to design a fair train-test split. Demonstrations include two examples of the planned real-world use of the model using a realistic multivariate synthetic dataset and the analysis of 148 wells from an undisclosed Equinor play. First, the workflow applies the semivariogram model of the target to compute the simple kriging variance as a proxy of spatial estimation difficulty based on the spatial data configuration. Second, the workflow employs a modified rejection sampling to generate a test set with similar prediction difficulty as the planned real-world use of the model. Third, we compare 100 test sets' realizations to the model's planned real-world use, using probability distributions and two divergence metrics: the Jensen-Shannon distance and the mean squared error. The analysis ranks the spatial fair train-test split method as the only one to replicate the difficulty (i.e., kriging variance) compared to the validation set approach and spatial cross-validation. Moreover, the proposed method outperforms the validation set approach, yielding a minor mean percentage error when predicting a target feature in an undisclosed Equinor play using a random forest model. The resulting outputs are training and test sets ready for model fit and assessment with any machine learning algorithm. Thus, the proposed workflow offers spatial aware sets ready for predictive machine learning problems with similar estimation difficulty as the planned real-world use of the model and compatible with any spatial data analysis task.

Description: Deep-sea polymetallic nodule mining is expected to start within the next decade. There is currently a pressing need to develop best practices to minimise the potential environmental impacts of this new industry. Project-specific environmental management processes, such as environmental impact assessment (EIA), and the associated environmental management and monitoring plan (EMMP), must be effective to sufficiently mitigate environmental impacts of deep-sea mining (DSM) projects. This paper identifies the key drivers, barriers, and enablers to polymetallic nodule mining from a review of recent literature and develops an environmental management framework prior to any exploitation licenses being approved. We explore how the drivers to polymetallic nodule mining are framed in a global context, including claims that it will facilitate clean energy transitions, increase mineral supply diversity, and improve life cycle sustainability. We highlight the key barriers to effective environmental management, including epistemic uncertainty about deep-sea ecosystems, assessment of harmful effects from mining activities, and stakeholder support for a social license. We identify three enablers, including the precautionary approach, the ecosystem approach, and adaptive management, all of which are highly interdependent and must be operationalised to address the identified barriers. The results of this analysis indicate a complex social-ecological narrative infused throughout recent literature, emphasising the need for systems-level thinking and broader stakeholder participation. We present an environmental management framework designed to support good industry practice and guide future research.

Description: Northern peatlands store 300–600 Pg C, of which approximately half are underlain by permafrost. Climate warming and, in some regions, soil drying from enhanced evaporation are progressively threatening this large carbon stock. Here, we assess future CO2 and CH4 fluxes from northern peatlands using five land surface models that explicitly include representation of peatland processes. Under Representative Concentration Pathways (RCP) 2.6, northern peatlands are projected to remain a net sink of CO2 and climate neutral for the next three centuries. A shift to a net CO2 source and a substantial increase in CH4 emissions are projected under RCP8.5, which could exacerbate global warming by 0.21°C (range, 0.09–0.49°C) by the year 2300. The true warming impact of peatlands might be higher owing to processes not simulated by the models and direct anthropogenic disturbance. Our study highlights the importance of understanding how future warming might trigger high carbon losses from northern peatlands.

Description: A 3D marine controlled-source electromagnetic (CSEM) survey for mapping hydrocarbons uses dozens of ocean-bottom electric (OBE) receivers deployed in a grid pattern and several transmitter towlines. This study considers seafloor massive sulfides (SMS) exploration, and the horizontal survey scale of SMS is a few kilometers, which is small compared with hydrocarbon surveys of tens of kilometers. If we apply a 3D CSEM survey using a receiver deployment on grids to map SMS, high survey costs will be incurred despite the small survey size. We have developed a cost-effective 3D marine CSEM survey that uses fewer receivers than the survey with a receiver deployment on grids to reduce survey costs for SMS. This CSEM survey uses a line of OBE receivers in the center of the survey area and several transmitter towlines. Numerical tests demonstrate that our survey (seven OBE receivers) using 80% fewer receivers than the survey with a receiver deployment on grids (35 OBE receivers) is able to accurately map SMS, obtaining a performance similar to that of the receiver deployment on grids. Then, we explore SMS in the Ieyama hydrothermal area off Okinawa, southwest Japan, using our 3D CSEM survey with a line of six OBE receivers and three transmitter towlines. The resulting 3D resistivity distribution from the observed data highlights three potential SMS zones consisting of 0.2 ohm-m low resistivity embedded into 1 ohm-m sediment.

Description: Increased water temperature is considered an important cause of the loss of seagrass beds. This paper quantified the interactive influence of different combinations of water temperature and duration on the responses of Zostera marina plants in terms of survivorship, morphology, growth and physiology. The LT50 (lethal temperature that caused an increase in mortality to 50% of that of the control) and ET50 (effect time that caused a decrease in growth to 50% of that of the control) were calculated to reveal the quantitative relationship between temperature and duration that resulted in limiting effects on the survival and growth of Z. marina plants. Z. marina plants were exposed to different combinations of water temperature [23 (control), 25, 27, 29, and 31 °C] and duration (5, 10, 15 and 20 days), and then the plants were transferred to the control condition for over 30 days under laboratory conditions. The results showed that the survival rate of plants at the end of recovery were significantly lower than those of plants at the end of direct impact under the temperature levels of 29 and 31 °C in each duration, indicating that short-term periods of obviously increased water temperature would lead to long-term effects on the survival of Z. marina plants. Regression analysis revealed that the relationship between water temperature and duration that resulted in limiting effects on the survival and growth of Z. marina could be described as a strong power function. Pearson correlation analysis showed that the survival and growth of Z. marina plants exposed to different temperature levels were significantly correlated with leaf soluble sugar contents. This study will further develop our understanding of the degradation and disappearance of seagrass beds induced by increased temperature.

Description: Highlights: • Wind-PV power mix beneficial for balancing variability due to weather. • Ratio of 45–57% for PV over PV plus wind power maximises balancing effects. • Simultaneous extremes in wind and PV power occur on less than 10% of the days. Abstract: The increasing use of wind and solar power requires interventions to balance the associated variability in energy production. One option to reduce the costly interventions is to exploit the natural de-correlation of wind and irradiance. This study characterises the balancing potential of the natual variability in wind and photovoltaic energy production within and across eleven European countries. We use 20 years of highly resolved meteorological data from a post-processed regional reanalysis with a 6 km horizontal grid to calculate daily photovoltaic and wind power. Our results suggest a country-dependent reduction of the day-to-day variability in energy production by 29%–42% due to installing both PV and wind power capacities, compared to wind power only. The optimized photovoltaic to photovoltaic plus wind power generation ratios are 45–57% for maximizing balancing effects associated with the changing weather. We further identify on less than 10% of the days a simultaneous occurrence of extremes in photovoltaic and wind power across European countries. The cross-border balancing potentials for the extremes in renewable energy production are therefore high due to the spatio-temporal differences of the local weather.

Description: This study investigates the mesoscale dynamics involved in the 8–11 October 2008 unseasonably strong African dust episode, during which dust was transported to the Iberian Peninsula (IP). We employ observational datasets and a high-resolution Weather Research and Forecasting model coupled with Chemistry simulations. The analysis shows that during 0900–1200 UTC 9 October, a mesoscale convective system developed over the Atlas Mountains and resulted in a southwestward propagating convective cold pool outflow on the southern foothills of the Anti-Atlas, which lifted dust from the source region. Between 1200 and 1800 UTC 9 October, new moist convection was enhanced over the Atlas Mountains due to intensifying confluence among a heat low, moist southwesterly Atlantic sea-breeze front, and northeasterly flow associated with the convective cold pool near western Algeria. This new moist convection intensified the strength of the convective cold pool outflow and haboob, both of which continued propagating southwestward. At 1200 UTC 10 October, the low-pressure system migrated poleward on the southern slopes of the Anti-Atlas Mountains in association with a mountain-plains solenoidal circulation due to the daytime differential heating between the southern slopes of the Anti-Atlas and nearby atmosphere. The deepening low-pressure and strengthening Atlantic sea-breeze redirected an equatorward advancing dust plume into the poleward direction. The dust plume ultimately crossed the Saharan Atlas Mountains on 11 October and finally impacted the IP. Key Points: - WRF-Chem simulation of an unseasonably strong haboob on the southern slopes of the Atlas Mountains - The equatorward-advancing dust plume was recirculated in the poleward direction by an Atlantic sea-breeze front - The Atlantic sea-breeze front and an intensified upper-level cutoff vortex are instrumental for dust transport over the Iberian Peninsula

Description: Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and inform on the mass loss that would contribute to future sea level rise. However, there is currently no consensus on estimated the future mass balance of the ice sheet, primarily because of differences in the representation of physical processes and the forcings employed. This study presents results from 18 simulations from 15 international groups focusing on the evolution of the Antarctic ice sheet during the period 2015–2100, forced with different scenarios from the Coupled Model Intercomparison Project Phase 5 (CMIP5) representative of the spread in climate model results. The contribution of the Antarctic ice sheet in response to increased warming during this period varies between −7.8 and 30.0 cm of Sea Level Equivalent (SLE). The evolution of the West Antarctic Ice Sheet varies widely among models, with an overall mass loss up to 21.0 cm SLE in response to changes in oceanic conditions. East Antarctica mass change varies between −6.5 and 16.5 cm SLE, with a significant increase in surface mass balance outweighing the increased ice discharge under most RCP 8.5 scenario forcings. The inclusion of ice shelf collapse, here assumed to be caused by large amounts of liquid water ponding at the surface of ice shelves, yields an additional mass loss of 8 mm compared to simulations without ice shelf collapse. The largest sources of uncertainty come from the ocean-induced melt rates, the calibration of these melt rates based on oceanic conditions taken outside of ice shelf cavities and the ice sheet dynamic response to these oceanic changes. Results under RCP 2.6 scenario based on two CMIP5 AOGCMs show an overall mass loss of 10 mm SLE compared to simulations done under present-day conditions, with limited mass gain in East Antarctica.

Description: An extensive, reprocessed two‐dimensional (2D) seismic data set was utilized together with available well data to study the Tiddlybanken Basin in the southeastern Norwegian Barents Sea, which is revealed to be an excellent example of base salt rift structures, evaporite accumulations and evolution of salt structures. Late Devonian–early Carboniferous NE‐SW regional extensional stress affected the study area and gave rise to three half‐grabens that are separated by a NW‐SE to NNW‐SSE trending horst and an affiliated interference transfer zone. The arcuate nature of the horst is believed to be the effect of pre‐existing Timanian basement grain, whereas the interference zone formed due to the combined effect of a Timanian (basement) lineament and the geometrical arrangement of the opposing master faults. The interference transfer zone acted as a physical barrier, controlling the facies distribution and sedimentary thickness of three‐layered evaporitic sequences (LES). During the late Triassic, the northwestern part of a salt wall was developed due to passive diapirism and its evolution was influenced by halite lithology between the three‐LES. The central and southeastern parts of the salt wall did not progress beyond the pedestal stage due to lack of halite in the deepest evaporitic sequence. During the Triassic–Jurassic transition, far‐field stresses from the Novaya Zemlya fold‐and‐thrust belt reactivated the pre‐salt Carboniferous rift structures. The reactivation led to the development of the Signalhorn Dome, rejuvenated the northwestern part of the salt wall and affected the sedimentation rates in the southeastern broad basin. The salt wall together with the Signalhorn Dome and the Carboniferous pre‐salt structures were again reactivated during post‐Early Cretaceous, in response to regional compressional stresses. During this main tectonic inversion phase, the northwestern and southeastern parts of the salt wall were rejuvenated; however, salt reactivation was minimized towards the interference transfer zone beneath the centre of the salt wall.

Description: Tephra deposits in Aotearoa New Zealand (ANZ) have been studied for 〉180 years. The now-global discipline of tephrochronology, which has some developmental roots in ANZ, forms the basis of a powerful chronostratigraphic correlational tool and age-equivalent dating method for geological, volcanological, palaeoenvironmental, and archaeological research in ANZ. Its utility is founded on the key principle that tephras or cryptotephras provide widespread isochrons in many different environments. In the first part of this article, we summarise the history of tephra studies in ANZ and then describe how tephras have been mapped, characterised, and correlated using field and laboratory-based methods. We document advances in geochemical fingerprinting of glass; tephra/cryptotephra detection and correlation by sediment-core scanning methods (e.g. X-radiography, CT imaging, XRF elemental analysis, magnetic susceptibility); statistical correlation methods; and dating of tephras/cryptotephras. We discuss the advent of ANZ cryptotephra studies (from mid-1970s) and their more-recent growth. The second part comprises examples of applications of tephrochronology in ANZ: climate-event stratigraphy (NZ-INTIMATE project); eruptive-event stratigraphy in the Auckland Volcanic Field; developments in the marine tephra record; advances in identifying, correlating, and dating old (pre-50 ka) tephras and weathered-tephra deposits; forming soils/paleosols on tephras; tephras and archaeology; Kopouatai bog tephrostratigraphy and palaeoenvironments; and volcanic-hazard assessments.

Description: Highlights • Shear strength in the BPT is estimated based on tensorial strain partitioning. • Accounting for full strain components resolves problems in the two-mechanism model. • Inclination of slip planes causes weakening relative to the friction law. • Fault-parallel compression is significant in the BPT and brittle regimes. A constitutive law of shear zones in the brittle-plastic transition (BPT) is of great importance to understanding loading at the bottom of the seismogenic layer preceding large earthquakes. Previous microphysics-based models are based on the partitioning of slip and dilation normal to the shear zone into different deformation mechanisms. Here, I account for the remaining 2-D strain component, inelastic extension of the shear zone, and associated stress buildup parallel to the shear zone, and investigate the steady-state behavior of a shear zone in which slip on inclined planes and bulk plastic flow coexist. Kinematic constraints and constitutive laws of the two mechanisms were solved numerically. The results show that the inclination of slip planes causes weakening relative to the friction law. Whereas the previous two-mechanism model yields a larger strength than the friction law for a rate-weakening slip element in the BPT, the present model qualitatively resolves this problem. Fault-parallel compression buildup can exceed the normal stress in the BPT and the brittle regime if the friction coefficient of the slip planes is in the range of Byerlee's law. This study illuminates the importance of fault-parallel compression in understanding the fabrics and strengths of shear zones.

Description: Degassing volcanic systems, expressed by fumaroles, thermal anomalies, and hydrothermal alteration and deposition at the surface provide insights into the underlying structural architecture and the magmatic system. While the fumarole sites are easily identified and investigated, areas of diffuse degassing and associated hydrothermal alteration are barely explored. Here we investigate high-resolution optical and thermal infrared (TIR) data, acquired by unoccupied aircraft systems (UAS) at the La Fossa cone (Vulcano Island) in November 2018. The data provides insights into the structural complexity of degassing sites and associated processes at the surface. Applying the Structure from Motion (SfM) approach, we generate a photomosaic database with a 0.05 m and 0.7 m pixel resolution for the optical and infrared datasets, respectively. A Principal Component Analysis (PCA) was applied to the optical data to detect, define and extract areas of hydrothermal alteration and sulfuric deposition on a pixel base, with a feature detection threshold of up to 25 cm2. By comparing optical data, PCA results and the IR data, we found a broad alteration zone dominated by diffuse degassing surrounding the main fumaroles, which with ~ 60,000 m2 is ten times larger than the area covered by fumaroles and yellowish sulfuric deposits. Spectral and thermal characteristics of this alteration zone suggest a segmentation into at least 13 distinct subregions. Hydrothermal alteration and deposition were analyzed considering their pixel density and spectral signature (RGB) and show the highest pixel density in the center of the fumarole field, accompanied by a systematic color shift. The same region is characterized by a systematic change in azimuths of thermal lineaments and sulfuric clusters from the dominating trend NW-SE by ~90 degrees to NE-SW. We conjecture this to be controlled by a permeability contrast due to a subsurface structure or crater intersection, facilitating a more direct gas ascent in the center of the fumarole field. We provide a precise and complete database for the state and extent of the La Fossa fumarole field, which can be used for comparative monitoring of spatio-temporal changes within the hydrothermal system at the surface.

Description: We report a novel hybrid, molecular and elemental mass spectrometry (MS) setup for the absolute quantification of snake venom proteomes shown here for two desert black cobra species within the genus Walterinnesia, Walterinnesia aegyptia and Walterinnesia morgani. The experimental design includes the decomplexation of the venom samples by reverse-phase chromatography independently coupled to four mass spectrometry systems: the combined bottom-up and top-down molecular MS for protein identification and a parallel reverse-phase microbore high-performance liquid chromatograph (RP-μHPLC) on-line to inductively coupled plasma (ICP-MS/MS) elemental mass spectrometry and electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QToF MS). This allows to continuously record the absolute sulfur concentration throughout the chromatogram and assign it to the parent venom proteins separated in the RP-μHPLC-ESI-QToF parallel run via mass profiling. The results provide a locus-resolved and quantitative insight into the three desert black cobra venom proteome samples. They also validate the units of measure of our snake venomics strategy for the relative quantification of snake venom proteomes as % of total venom peptide bonds as a proxy for the % by weight of the venom toxins/toxin families. In a more general context, our work may pave the way for broader applications of hybrid elemental/molecular MS setups in diverse areas of proteomics.

Description: Quinoa (Chenopodium quinoa Willd.), an herb belonging to the amaranth family, is rich in minerals, amino acids, vitamins, proteins, and flavonoids. Its grain, compared with other major grains, has unique nutritional value with tremendous applications. This study used four independently bred high-generation lines (seed colors) of quinoa as materials to further understand the metabolic differences in the filling periods of quinoa varieties. Additionally, the non-targeted metabolome of quinoa seeds 35 and 42 days after flowering, respectively, were studied via liquid chromatography-mass spectrometry. The two filling periods of yellow, white, black, and red quinoa grains resulted in significant differences in the metabolites, particularly in L-methionine, S-adenosyl-L-homocysteine, S-adenosyl-L-methionine, pyruvate, fumarate, and oxaloacetate. Soluble sugar, amino acid, and fatty acid contents in quinoa increased after 42 days of flowering. There were metabolic differences between the sugar phosphates (L-fucose, D-mannose-6-phosphate, xylulose-5-phosphate, sedoheptulose-7-phosphate), amino acid (alanine), and organic compounds (kynurenate, tryptamine, serotonin, bilirubin) among the four quinoa varieties. The relative difference in the metabolites was largest when the yellow quinoa grain was compared with the other quinoa varieties and smallest when the red and black varieties were compare. The results of this study provide a basis for the reproduction and identification of new quinoa varieties, as well as for screening potential quality control target genes by combining genomics and transcriptomics.

Description: During recent years, terrestrial and extraterrestrial ocean research have increasingly joined forces to merge expertise and technical solutions in the exploration of marine systems on Earth and in space. This includes solutions for robotic applications, autonomy and sensor integration, as well as data analysis. These synergies in biomimetic design, platform artificial intelligence (AI) and life-tracing sensor packages will be applied to the monitoring and surveillance of environmentally delicate habitats on Earth such as cold-water coral reefs or fishing grounds, as well as decommissioning sites. Thus, marine scientific and industrial offshore infrastructures may provide innovative test-bed services for robotics and sensor development.

Description: Highlights • Release of additives from plastic pollution may harm wildlife. • Robust methods to characterise additives and their leaching behaviour are needed. • Extraction and leaching methods are informed from well-established industry methods. • Recommended approaches for extraction and leaching studies are presented. • The use of environmentally relevant methods and test materials is advised. Plastic pollution is prevalent worldwide and has been highlighted as an issue of global concern due to its harmful impacts on wildlife. The extent and mechanism by which plastic pollution effects organisms is poorly understood, especially for microplastics. One proposed mechanism by which plastics may exert a harmful effect is through the leaching of additives. To determine the risk to wildlife, the chemical identity and exposure to additives must be established. However, there are few reports with disparate experimental approaches. In contrast, a breadth of knowledge on additive release from plastics is held within the food, pharmaceutical and medical, construction, and waste management industries. This includes standardised methods to perform migration, extraction, and leaching studies. This review provides an overview of the approaches and methods used to characterise additives and their leaching behaviour from plastic pollution. The limitations of these methods are highlighted and compared with industry standardised approaches. Furthermore, an overview of the analytical strategies for the identification and quantification of additives is presented. This work provides a basis for refining current leaching approaches and analytical methods with a view towards understanding the risk of plastic pollution.

Description: We processed three quinoa ecotypes as they are commonly consumed in a daily diet. For the treatments, quinoa seeds were washed, cooked, and/or germinated. Following treated, we used 1H NMR-based metabolomic profiling to explore differences between the ecotypes. Then, for a non-targeted and targeted food fingerprint analysis of samples, we performed multivariable data analyses, including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and hierarchical cluster analysis. From our study, we were able to discriminate each quinoa ecotype regardless of treatment based on its metabolomic profiling. Additionally, we were able to identify 30 metabolites that were useful to determine the effect of each treatment on nutritional composition. Germination increased the content of most metabolites irrespective of ecotype. In general, ecotype CQE_03 was different from ecotypes CQE_01 and CQE_02. Our phytochemical analysis revealed the effects of washing, cooking, and/or germination, particularly on saponins content.

Description: Highlights • Carbon dioxide + propane mixtures are studied through accurate measurements of speeds of sound and phase equilibria. • Heat capacities and virial coefficients are obtained from speeds of sound. • Retrograde condensation zone is found for the (0.60 CO2 + 0.40 C3H8) mixture. • Results are compared with reference equations of state such as GERG-2008 and AGA8-DC92. This work presents phase envelope and speed of sound data for the (0.60 CO2 + 0.40 C3H8) and (0.80 CO2 + 0.20 C3H8) binary mixtures. Phase equilibria was measured using a cylindrical resonator working in the microwave band whereas an acoustic resonator was used for speed of sound measurements. The experimental results were compared with GERG-2008 equation of state, obtaining average absolute deviations by 0.24% in pressure for phase equilibria data and 0.025% for speed of sound data. Speed of sound values were used to derive perfect-gas heat capacities, acoustic virial coefficients, and second density virial coefficients. In addition, AGA8-DC92 equation of state performance was checked for the results derived from speeds of sound.

Description: Opportunities to include Cetancodontamorpha in the study of the evolution of the immune system in the clades of Artiodactylamorpha, Ruminantiamorpha, Suinamorpha, and Camelidamorpha have increased with the use of the bottlenose dolphin, Tursiops truncatus, as a sentinel species to study the effects of environmental pollutants on the health of marine mammals. Efforts are currently underway to increase the number reagents needed for detailed studies. Thus far, screening of monoclonal antibodies (mAbs) made to leukocyte differentiation molecules (LDM) and the major histocompatibility (MHC) class I and class II molecules in Ruminantiamorpha have yielded some mAbs that recognize conserved epitopes expressed on orthologues in the bottlenose dolphin. More direct approaches are in progress to identify additional mAbs to bottlenose LDM and cytokines. As reported here, both direct and indirect approaches were used to identify mAbs specific for cytokines useful in monitoring the effects of environmental pollutants on the immune system. Immunization of mice with expressed bottlenose dolphin cytokines yielded mAbs specific for IFN-γ, TNF-α, IL-6, IL-8, IL-10, and IL-17A. Screening of previously developed mAbs used in livestock immunology research revealed mAbs developed against ovine IFN-γ and bovine IL-17 and IL-1β recognize conserved epitopes in bottlenose dolphin orthologues. The mAbs identified in the present study expand the reagents available to study the function of the immune system in bottlenose dolphins and cattle.

Description: Sorghum bran, containing high-value lipids and phenolic compounds, is an underutilized food processing byproduct. This study developed and optimized a green method based on a sequential pure supercritical carbon dioxide (SC–CO2) and ethanol/water-modified SC–CO2 extraction to extract wax-rich lipids and phenolic compounds from sorghum bran in a single step. The extraction conditions, namely, temperature (20–100 °C), pressure (20–40 MPa), extraction time (0.5–5 h), and cosolvent type (ethanol or ethanol–water), were optimized for the highest wax-rich lipids and phenolics extraction yields. In the first part, neat SC–CO2 at 40 MPa and 60 °C resulted in the highest lipid yield (6.2%, w/w dry basis), which contained ∼5% (w/w) high-melting point waxes. The purified wax fractions containing phytosterols showed high melting points of 57–87 °C. In the second part, the highest total phenolics and flavonoids yields were achieved at 40 MPa and 40 °C via 15% (w/w) ethanol–water (1:1, v/v) modified SC–CO2 by 150 ± 3 mg of gallic acid equivalent (GAE)/100 g of bran (dry basis) and 99.6 ± 4 mg of catechin equivalent (CAE)/100 g of bran (dry basis), respectively. Overall, this study provides a novel single-step extraction approach based on SC–CO2 to extract and fractionate lipids and phenolic compounds from sorghum bran.

Description: The ecological role of large thecosome pteropods in the pelagic ecosystem of the northern Gulf of Mexico (GoM) may be substantial, both in the food web and biogeochemical cycling. We analyzed species abundances, vertical and horizontal distributions of large species with calcareous shells (those collected in 3-mm mesh nets). Pteropod samples were collected following the 2010 Deepwater Horizon oil (DWH) spill by two midwater sampling programs: the Offshore Nekton Sampling and Analysis Program (ONSAP 2011) and the Deep Pelagic Nekton Dynamics of the Gulf of Mexico (DEEPEND 2015) projects. All samples were collected using a 10-m2 Multiple Opening/Closing Net and Environmental Sensing System (MOC10) midwater trawl, with 3-mm mesh. This gear sampled five discrete depths between 0–1500 m. Over 13,000 pteropod specimens were examined, with 25 species identified. Clio pyramidata Linnaeus 1767 was the most abundant species during both collection periods. Five genera (Diacria, Clio, Styliola, Cuvierina, Cavolinia) demonstrated diel vertical migration from the mesoto epipelagic zone.

Description: We propose a new, sunken continent beneath the North Atlantic Ocean that we name Icelandia. It may comprise blocks of full-thickness continental lithosphere or extended, magma-inflated continental layers that form hybrid continental-oceanic lithosphere. It underlies the Greenland-Iceland-Faroe Ridge and the Jan Mayen microplate complex, covering an area of ~600,000 km2. It is contiguous with the Faroe Plateau and known parts of the submarine continental rifted margin offshore Britain. If these are included in a “Greater Icelandia,” the entire area is ~1,000,000 km2 in size. The existence of Icelandia needs to be tested. Candidate approaches include mag- netotelluric surveying in Iceland; ultralong, full-crust-penetrating reflection profiling along the length of the Greenland-Iceland-Faroe Ridge; dating zircons collected in Ice- land; deep drilling; and reappraisal of the geology of Iceland. Some of these methods could be applied to other candidate sunken continents that are common in the oceans.

Description: Consistently high data quality is essential for the development of novel loss functions and architectures in the field of deep learning. The existence of such data and labels is usually presumed, while acquiring high-quality datasets is still a major issue in many cases. Subjective annotations by annotators often lead to ambiguous labels in real-world datasets. We propose a data-centric approach to relabel such ambiguous labels instead of implementing the handling of this issue in a neural network. A hard classification is by definition not enough to capture the real-world ambiguity of the data. Therefore, we propose our method “Data-Centric Classification & Clustering (DC3)” which combines semi-supervised classification and clustering. It automatically estimates the ambiguity of an image and performs a classification or clustering depending on that ambiguity. DC3 is general in nature so that it can be used in addition to many Semi-Supervised Learning (SSL) algorithms. On average, our approach yields a 7.6% better F1-Score for classifications and a 7.9% lower inner distance of clusters across multiple evaluated SSL algorithms and datasets. Most importantly, we give a proof-of-concept that the classifications and clusterings from DC3 are beneficial as proposals for the manual refinement of such ambiguous labels. Overall, a combination of SSL with our method DC3 can lead to better handling of ambiguous labels during the annotation process. (Source code is available at https://github.com/Emprime/dc3).

Description: Artificial neural networks (ANNs) are known to be powerful methods for many hard problems (e.g. image classification, speech recognition or time series prediction). However, these models tend to produce black-box results and are often difficult to interpret. Layer-wise relevance propagation (LRP) is a widely used technique to understand how ANN models come to their conclusion and to understand what a model has learned. Here, we focus on Echo State Networks (ESNs) as a certain type of recurrent neural networks, also known as reservoir computing. ESNs are easy to train and only require a small number of trainable parameters, but are still black-box models. We show how LRP can be applied to ESNs in order to open the black-box. We also show how ESNs can be used not only for time series prediction but also for image classification: Our ESN model serves as a detector for El Nino Southern Oscillation (ENSO) from sea surface temperature anomalies. ENSO is actually a well-known problem and has been extensively discussed before. But here we use this simple problem to demonstrate how LRP can significantly enhance the explainablility of ESNs.

Description: The Tristan da Cunha islands are located 450 km east of the Mid-Atlantic Ridge and 60 km north of the Tristan da Cunha transform fault, and fracture zone system in the Atlantic Ocean. The islands are products of intraplate hotspot volcanism. However, several controversies are associated with theories for the origin of the Tristan da Cunha hotspot. Previous magnetotelluric data 3-D inversion results based on finite-difference algorithm couldn’t image plume-like vertical structure, unlike many geological and geochemical studies (Baba et al., 2017). In this study, we revisit the electrical structure of the region by inverting combined vertical magnetic transfer functions and the MT responses from seafloor stations around the islands and those newly obtained on the Tristan da Cunha and Nightingale islands. The topographic effect is one of the keys to obtaining a more reliable subsurface structure, and therefore, we use two finite-element-based inversion methods of Usui (2021) and Grayver (2015). For inversion analysis, we compared the topographic responses from these methods and a finite-difference-based forward modeling method (Baba & Seama, 2002; Baba & Chave, 2005) used in the previous study (Baba et al., 2017). The responses for sites with minimum topography effects are almost identical from all the three methods except for some sites where difference is observed in shorter periods. This could be due to the difference in the mesh resolution around the sites. The responses for sites with significant topography effects show a reasonable match for the finite-element methods in longer periods. In contrast a significant difference is observed in responses from all three methods for short periods. The comparison of modeled responses proves the applicability of Usui’s inversion scheme to MT data from this region. In the workshop, the inversion results from Usui’s inversion method will be presented.

Description: Offshore groundwater systems have been suggested as alternative sources of potable water in islands and coastal regions. In this study, we integrate offshore controlled-source electromagnetic (CSEM) with borehole data to identify an offshore groundwater system in the Canterbury Bight, New Zealand. CSEM data were acquired with a seafloor-towed system along four profiles and 2-D inversion was carried out using MARE2DEM to derive resistivity models along each profile. Moreover, a trans-dimensional Bayesian inversion was conducted to assess the distribution of plausible resistivity-depth models. The study area was previously investigated during IODP Expedition 317 in which a pore-fluid salinity anomaly (24 psu at 40 mbsf) was recorded in borehole U1353. A comparison between the CSEM resistivity model and the resistivity-depth profile converted from pore-water salinity within the borehole shows a strong correlation between CSEM and borehole data at the closest waypoint to site U1353. We show through a Markov-Chain Monte Carlo approach that our estimates of seafloor resistivity agree with the measured borehole data. The computed resistivity distributions at the borehole provide significant evidence that the CSEM inversion models can be used to extrapolate groundwater inferences from the borehole onto a basin scale providing improved geophysical imaging capabilities for offshore freshened groundwater.

Description: Algen, Zooplankton und Fische gehören zu den Schlüsselakteuren der biologischen Kohlenstoffpumpe, mithilfe derer der Ozean der Atmosphäre auf natürliche Weise Kohlendioxid entnimmt und den enthaltenen Kohlenstoff in großen Wassertiefen einlagert. Damit dieser Mechanismus jedoch optimal funktioniert, braucht es Nährstoffe, die vielerorts fehlen, zumindest im lichtdurchfluteten Oberflächenwasser. Durch das Heraufpumpen nährstoffreichen Tiefenwassers könnte der Mensch diesen Nährstoffmangel beheben. Ob ein solcher künstlicher Auftrieb aber tatsächlich klimawirksam wäre, welche Risiken er mit sich brächte und ob er technisch und rechtlich im großen Stil umgesetzt werden könnte, ist bislang ungewiss. Die Forschungsmission CDRmare liefert Antworten.

Description: Large amounts of atmospheric carbon can be exported and retained in the deep sea on millennial time scales, buffering global warming. However, while the Barents Sea is one of the most biologically productive areas of the Arctic Ocean, carbon retention times were thought to be short. Here we present observations, complemented by numerical model simulations, that revealed a deep and widespread lateral injection of approximately 2.33 kt C d−1 from the Barents Sea shelf to some 1,200 m of the Nansen Basin, driven by Barents Sea Bottom Water transport. With increasing distance from the outflow region, the plume expanded and penetrated into even deeper waters and the sediment. The seasonally fluctuating but continuous injection increases the carbon sequestration of the Barents Sea by 1/3 and feeds the deep sea community of the Nansen Basin. Our findings combined with those from other outflow regions of carbon-rich polar dense waters highlight the importance of lateral injection as a global carbon sink. Resolving uncertainties around negative feedbacks of global warming due to sea ice decline will necessitate observation of changes in bottom water formation and biological productivity at a resolution high enough to quantify future deep carbon injection.

Description: The Net-Zero-2050 cluster aims for a national roadmap for net zero CO2 emissions by 2050, including integrated scenario analyses and negative emission technology assessment (see fact sheet Net-Zero-2050 Structure Project 1). This national target to substantially reduce national CO2 emissions by 2050 stems from the objective to comply with the global long-term temperature goal of well below 2°C of the Paris Agreement (UNFCCC, 2015). Within the cluster it is therefore important to decide on an approach for deriving a national remaining carbon budget from global emissions trajectories in agreement with the Paris Climate Agreement’s longterm temperature goal (UNFCCC, 2015). Allocating national carbon budgets is a balance of environmental effectiveness, equity, national capacity and ability, political feasibility, economic efficiency and technical requirements (Gignac and Matthews, 2015; Höhne et al., 2003; 2014). Given Germany’s capacity and abilities, we decided to follow a sustainable growth trajectory with a convergence phase to equal-per-capita CO2 emissions by 2035, and a net zero CO2 emissions trajectory after 2050 until the end of the century. This approach leads to a remaining Germany CO2 budget of 9 GtCO2 (from 1st January 2018 to 2050 and 2100), which we propose to be used across the Net-Zero-2050 cluster. The remaining carbon budget will serve as a target to be used in all work packages in a concerted way, either qualitatively or quantitatively, and in accordance with other work packages (see also fact sheet Net-Zero-2050 Energy Scenario Approach). The calculated budget is at the lower end of the national budget if allocated by the grandfathering approach (emissions are allocated with respect to today’s emissions shares: 5.5-13.1 GtCO2), but slightly higher than the highest estimate of an equal-per-capita remaining carbon budget (emissions are allocated with respect to Germany’s share of the global population: 3.5-8.4 GtCO2) The 9 GtCO2 national remaining CO2 budget, 6.9 GtCO2 from 1st January 2021, will need to be broken down by category (e.g. energy, land use, industrial processes, and man-made sinks and sources; see Gap Analysis Report) in order to provide a consistent approach across work packages.