bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring climate change impact on groundwater supporting a medium and long term water management planning, a case study in Northern Italy.
Authors: Redaelli Agnese , Rotiroti Marco , Bonomi Tullia , Fumagalli Letizia , Caschetto Mariachiara , Esposto Francesco , Sinatra Gianfranco , Olivieri Mauro , Bozza Sonia , Zanotti Chiara
Published: March 2022

Groundwater systems are going to play an increasingly important role in facing climate change, representing one of the most significant worldwide water sources. At the same time, climate change may inevitabily lead to considerable direct and indirect impacts on groundwater systems.

The aim of this work is the development of a knowledge framework for groundwater bodies in relation to water availability and its vulnerability to possible climate change scenarios, identifying the mitigation action that can be adopted to resiliently respond to changes. The study area is the province of Brescia, in northern Italy, including 100 municipalities served by 183 wells and 98 springs. This area includes a higher plain, hosting a unconfined acquifer, a lower plain with several layered confined acquifers and two morainic amphitheaters.

To define the evolutionary scenarios of groundwater resources at basin and sub-basin scale, hydrodynamic conditions and temporal trends, over a time span from 2009 to 2021, have been evaluated.

Groundwater availability data have been analysed in relation to hydro-nivo-meteorological data collected from the meteorological stations distributed in the area. Mann-Kendall and Sen Slope estimator have been applied for trend identification and changing point analysis to explore groundwater time series.

Regarding precipitation, a first analysis aimed at the identification of extreme phenomena through the yearly distributions of dry and rainy days and through the calculation of specific indices such as SPI (Standard Precipitation Index) and PCI (Precipitation Concentration Index).

The piezometric and precipitation series have been subjected to time series decomposition, a mathematical procedure that splits the original series into three sub-components: seasonal, trend, and random. Successively, a comparative analysis has been performed between the three components of groundwater levels and the three components of the neighboring rain stations data.

This methodology allowed to investigate the actual effect of precipitation on groundwater level variability with respect to the other components that contribute to the total water budget: it emerged that in the higher plain the effects of irrigation return flow contributes to the summer groundwater table rise more than precipitation, and that in the lower plain groundwater table depth is more related to human abstraction than local precipitation. These results provide the basis for implementing future sustainable water management plans.
Mapping areas suitable for artificial recharge structures in the Ropar District of Punjab, India
Authors: Prashanth Thallam , Banerjee Dolon , Ganguly Sayantan
Published: March 2022

Groundwater is an important resource in India as it is used extensively for industrial, agricultural and drinking purposes. With the increase in demand due to growth in population, industrialization and improvement of living standards, the groundwater resources in India are depleting. For instance, the long-term trend of groundwater level observed in the Ropar district of Punjab, India for a span of ten years shows a gradual decline. The maximum fall of groundwater level is observed to be 1.05 m/year. In Ropar, the natural recharge process is diminishing because of rapid urbanization, variation in rainfall, and temperature patterns. Therefore the available water is found to be insufficient to fulfil the rise in water demand.To replenish the declining groundwater table and thus maintain the balance between the water supply and demand, artificial recharge techniques are proven to be beneficial in various studies. In this study, areas suitable for artificial recharge have been proposed.Remote Sensing(RS) techniques and the Geographic Information System(GIS) has been used to prepare various thematic maps constituting slope, land use & land cover, soil, geomorphology, the thickness of granular zone (permeable zones), the distance between recharge structure and the Sutlej river, rainfall map, drainage density, and population density. Lithological mapping in and around the Ropar district has been analyzed using borehole logs and reports from Central Ground Water Board, Govt. of India. Analytical Hierarchical Process (AHP) and Artificial Neural Networks (ANN) model have been used to determine the weightage of different parameters to map the suitable areas required for artificial recharge in the Ropar District. Finally, the best type of artificial recharge structure has been chosen based on higher stream order, drainage density and lithology for the present scenario.
Direct evidence of an oceanic dual kinetic energy cascade and its seasonality from surface drifters
Authors: Xie Jin-Han , Balwada Dhruv , Marino Raffaele , Feraco Fabio
Published: March 2022

Ocean turbulence causes flows to split into smaller whirls or merge to make larger whirls, cascading energy to small or large scales respectively. Conventional ocean dynamics dictates that the kinetic energy in the ocean will cascade primarily to larger scales, via the inverse energy cascade, and has raised the question of how the kinetic energy in the ocean dissipates, which would necessarily require the transfer towards the molecular scales. However, so far no clear observational quantification of the energy cascade at the scales where these mechanisms are potentially active has been made. By using forcing-scale resolving third-order structure-function theory, which captures bidirectional energy fluxes and is applicable beyond inertial ranges, we analyse data from surface drifters, released in dense arrays in the Gulf of Mexico, to obtain the kinetic energy flux magnitude and directions along with the energy injection scales. We provide the first direct observational verification that the surface kinetic energy cascades to both small and large scales, with the forward cascade dominating at scales smaller than approximately 1-10km. Our results also show that there is a seasonality in these cascades, with winter months having a stronger injection of energy into the surface flows and a more energetic cascade to smaller scales. This work provides exciting new opportunities for further probing the energetics of ocean turbulence using non-gridded sparse observations, such as from drifters, gliders, or satellites.
Fast and sensitive detection of amino sugar, neutral sugar and uronic acid biomarkers using 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization and reversed phase liquid chromatography coupled to Orbitrap mass spectrometry
Authors: Salas Erika , Kaiser Christina , Wanek Wolfgang
Published: March 2022

Soil organic matter is composed to a large extent of microbial necromass, including fragmented cell wall residues and other cytoplasmic components from dead fungi and bacteria. These components accumulate in soil over long periods of time and have been used as biomarkers to trace microbial residues. Amino sugars are key components of microbial cell walls and can be found in polymeric forms as fungal chitin and bacterial peptidoglycan in soils. Among the most abundant amino sugars in soil are glucosamine, galactosamine, mannosamine and muramic acid. Glucosamine is used as a biomarker for both fungal and bacterial necromass, while muramic acid is exclusively found in bacterial peptidoglycan. Neutral sugars can also be used as biomarkers, where pentose:hexose ratios are used to determine the contribution of plant biomass relative to microbial necromass to soil organic matter (SOM). Potentially uronic acids can also be used as plant versus microbial biomarkers. Acid hydrolysis breaks apart polymers such as peptidoglycan, chitin, and plant matter into monomers, which can later be quantified to estimate the contribution of bacterial, fungal and plant necromass to stabilized SOM. Due to their structural similarity and complexity, high-throughput identification and quantification of these compounds has remained a challenge. Derivatization using 1-phenyl-3-methyl-5-pyrazolone (PMP) has been used to characterize carbohydrates because of its simple and rapid reaction mechanism and enhanced ionization efficiency with ESI-MS. Our aim was to develop a highly sensitive method to quantify sugar-containing compounds in a single rapid assay using pre-column PMP derivatization. Separation and quantification of the PMP-derivatives was carried out using reversed-phase ultra-high performance liquid chromatography (RP-UHPLC) coupled to high resolution-high accuracy Orbitrap mass spectrometry (MS). Our method allowed the simultaneous separation and quantification of >20 compounds, including hexosamines, muramic acid, N-acetylhexosamines, hexuronic acids, pentoses, hexoses, deoxyhexoses, cellobiose, chitobiose, and chitotriose. All PMP derivatives were separated within 20 minutes. This method provides high resolution and high sensitivity for the quantification of diverse sugar-related compounds in one single assay, which demonstrates its potential in measuring complex and heterogeneous mixtures. Likewise, this method can also be applied in isotope tracing studies, where the turnover and stabilization of 15N and 13C labeled compounds in necromass are traced through the different soil pools using UPLC-Orbitrap mass spectrometry.
P mobilization by an extreme rainfall event and its spatial variability in an agroforestry South-Pyrenean catchment 
Authors: Ramos Maria Concepción , Lizaga Ivan , Gaspar Leticia , Navas Ana
Published: March 2022

High intensity rainfall events produce not only significant soil losses but also nutrient losses which act as important sources of water pollution. In particular, those erosion processes contribute significantly to phosphorous (P) losses and its transportation along the catchments. The high-intensity events that occurred during the last decade and the projected increase under climate change scenarios, suggest the need for a more in-depth analysis of the associated effect of rainfall on the mobilization and export of P from a catchment. Nevertheless, the P losses are influenced not only by rainfall characteristics but also by land use and by soil properties. The agricultural lands have been pointed out as the main contributor to P losses, but other landscape elements should be taken into account. In addition, the form in which P is linked to soil particles also conditions the processes. The aim of this research was to evaluate the effects of an extraordinary event on P mobilization in areas under different land use in an agroforestry catchment of the South Pyrenean region (Aragón, Spain), as well as the variability in the processes along the channel beds in three nested subcatchments. P concentrations in soils under different land use and the sediments in the channels were assessed before and after an extreme event in three nested sub-catchments and related to other soil properties. The results showed that in the study catchment, P was mostly linked to the mineral fraction (mainly to silicates), while the binding between P and OM was only observed in the soils under forest land use. The high intensity rainfall event produced a significant change in the particle size distribution with the loss of fine material (clay and silt) and OM leading to an enrichment of the sediments in P. It was also confirmed that, in addition to the agricultural lands, which had the highest P concentration and were more prone to suffer erosion and contribute to P release, the channel banks and the own beds of the channels should be considered as contributors to P exportation. The higher P concentration in the channel beds after the extreme events leads to higher P levels exposed to be eroded. The variability of P concentration along the nested channels was in agreement with the increase of magnitude of the erosion processes along the streams.
Exploring flooding mechanisms and their trends in Europe through explainable AI
Authors: Jiang Shijie , Zheng Yi , Zscheischler Jakob
Published: March 2022

Understanding the mechanisms causing river flooding and their trends is important to interpret past flood changes and make better predictions of future flood conditions. However,  there is still a lack of quantitative assessment of trends in flooding mechanisms based on observations. Recent years have witnessed the increasing prevalence of machine learning in hydrological modeling and its predictive power has been demonstrated in numerous studies. Machine learning makes hydrological predictions by recognizing generalizable relationships between inputs and outputs, which, if properly interpreted, may provide us further scientific insights into hydrological processes. In this study, we propose a new method using interpretive machine learning to identify flooding mechanisms based on the predictive relationship between precipitation and temperature and flow peaks. Applying this method to more than a thousand catchments in Europe reveals three primary input-output patterns within flow predictions, which can be associated with three catchment-wide flooding mechanisms: extreme precipitation, soil moisture excess, and snowmelt. The results indicate that approximately one-third of the studied catchments are controlled by a combination of the above mechanisms, while others are mostly dominated by one single mechanism. Although no significant shifts from one dominant mechanism to another are observed for the catchments over the past seven decades overall, some catchments with single mechanisms have become dominated by mixed mechanisms and vice versa. In particular, snowmelt-induced floods have decreased significantly in general, whereas rainfall has become more dominant in causing floods, and their effects on flooding seasonality and magnitude are crucial. ​Overall, this study provides a new perspective for understanding climatic extremes and demonstrates the prospect of artificial intelligence(AI)-assisted scientific discovery in the future.
An approach to integrate GPR thickness variability and roughness level into pavement performance evaluation
Authors: Plati Christina , Loizos Andreas , Georgouli Konstantina
Published: March 2022

It is a truism that pavements deteriorate due to the combined effects of traffic loads and environmental conditions. The manner or ability of a road to meet the demands of traffic and the environment and to provide at least an acceptable level of performance to road users throughout its life is referred to as pavement performance. An important indicator of pavement performance is ride quality. This is a rather subjective measure of performance that depends on (i) the physical properties of the pavement surface, (ii) the mechanical properties of the vehicle, and (iii) the acceptance of the perceived ride quality by road users. Due to the subjectivity of ride quality assessment, many researchers have worked in the past to develop an objective indicator of pavement quality. The International Roughness Index (IRI) is considered a good indicator of pavement performance in terms of road roughness. It was developed to be linear, transferable, and stable over time and is based on the concept of a true longitudinal profile. Following the identification and quantification of ride quality by the IRI, pavement activities include the systematic collection of roughness data in the form of the IRI using advanced laser profilers, either to "accept" an as-built pavement or to monitor and evaluate the functional condition of an in-service pavement.

On the other hand, pavement performance can vary significantly due to variations in layer thickness, primarily due to the construction process and quality control methods used. Even if a uniform design thickness is specified for a road section, the actual thickness may vary. It is expected that the layer thickness will have some probability distribution, with the highest density being around the target thickness. Information on layer thickness is usually obtained from as-built records, from coring or from Ground Penetrating Radar (GPR) surveys. GPR is a powerful measurement system that provides pavement thickness estimates with excellent data coverage at travel speeds. It can significantly improve pavement structure estimates compared to data from as-built plans. In addition, GPR surveys are fast, cost effective, and non-destructive compared to coring.

The present research developed a sensing approach that extends the capability of GPR beyond its ability to estimate pavement thickness. Specifically, the approach links GPR thickness to IRI based on the principle that a GPR system and a laser profiler are independent sensors that can be combined to provide a more complete image of pavement performance. To this end, field data collected by a GPR system and a laser profiler along highway sections are analyzed to evaluate pavement performance and predict future condition. The results show that thickness variations are related to roughness levels and specify the deterioration of the pavement throughout its lifetime.
Flood forecasting using sensor network and Support Vector Machine model
Authors: Langhammer Jakub
Published: March 2022

Machine learning has shown great promise for hydrological modeling because, unlike conventional approaches, it allows efficient processing of big data provided by the recent automatic monitoring networks. This research presents the Support Vector Machine (SVM) model designed for modeling floods in a montane environment based on data from a distributed automated sensor network. The study aimed to test the reliability of the SVM model to predict the different types of flood events occurring in the environment of a mid-latitude headwater basin, experiencing the effects of climate and land use change. 

The sensor network uses four hydrological and two meteorological stations, located in headwaters of the montane basin of Vydra, experiencing intense forest disturbance, a rise in air temperatures, and frequent occurrence of flood events. Automated hydrological stations are operating in the study area for ten years, recording the water levels in a 10-minute interval with online access to data. Meteorological stations monitor air temperatures, precipitation, and snow cover depth at the same time step. 

The model network was built using the Support Vector Machines (SVM), particularly the nu-SVR algorithm, employing the LibSVM library. The network was trained and validated on a complex sample of hydrological observations and tested on the scenarios covering different types of extreme events. The simulation scenarios included the floods from a single summer storm, recurrent storms, prolonged regional rain, snowmelt, and a rain-on-snow event. 

The model proved the robustness and good performance of the data-driven SVM model to simulate hydrological time series. The RMSE model performance ranged from 0,91-0,97 for individual scenarios, without substantial errors in the fit of the trend, timing of the events, peak values, and flood volumes. The model reliably reconstructed even the complex flood events, such as rain on snow episodes and flooding from recurrent precipitation. 

The research proved that the data-driven SVM model provides a reliable and robust tool for simulating flood events from sensor network data. The model proved reliability in a montane environment featuring rapid runoff generation, transient environmental conditions, and variability of flood event types. The SVM model proved to efficiently handle big data volumes from sensor networks and, under such conditions, is a promising approach for operational flood forecasting and hydrological research. 
Wavelet Analysis of Soil Water State Variables for Identification of Lateral Subsurface Flow: Lysimeter versus Field Data 
Authors: Ehrhardt Annelie , Groh Jannis , Gerke Horst H.
Published: March 2022

Preferential and lateral subsurface flow may be responsible for the accelerated transport of water and solutes in sloping agricultural landscapes; however, the process is difficult to observe. One idea is to compare time series of soil moisture observations in the field with those in lysimeters, where flow is vertically oriented. This study aims at identifying periods of deviations in soil water contents and pressure heads measured in the field and in a weighing lysimeter with the same soil profile. Wavelet Coherency Analysis (WCA) was applied to time series of hourly soil water content and pressure head data (15, 32, 60, 80, and 140 cm depths) from Colluvic Regosol soil profiles in summer 2017. The phase shifts and periodicities indicated by the WCA plots reflected the response times to rain events in the same depth of lysimeter and field soil. For many rain events and depths, sensors installed in the field soil showed a faster response than those in the lysimeters soil. This could be explained by either vertical preferential flow or lateral subsurface flow from upper hillslope positions. Vice versa, a faster sensor response in the lysimeter soil could be indicative for vertical preferential effects. The WCA plots comprise all temporal patterns of time shifts and correlations between larger data time series’ in a condensed form to identify potentially relevant periods for more detailed analyses of subsurface flow dynamics.
Trace analysis of organic aerosol markers and lignin in samples from Alpine ice core Colle Gnifetti covering the 20th century using UHPLC-HRMS
Authors: Beschnitt Anja , Schäfer Johanna , Schwikowski Margit , Hoffmann Thorsten
Published: March 2022

Ice cores are valuable climate archives preserving organic compounds from atmospheric aerosols over long time ranges. Different approaches of dating are available like annual layer counting, radioactive decay and stratigraphic markers like tephra from volcanic eruption. In combination, they enable accurate dating back to 800,000 years. Secondary organic aerosols (SOA) are formed in the atmosphere by condensation of oxidized highly volatile organic compounds and their chemical profile is highly complex due to the variety of emission sources and reactions in the atmosphere.

Well-known SOA markers include pinic acid, pinonic acid or terebic acid from monoterpene oxidation. Another class of important atmospheric markers are biomass burning products. During combustion of cellulose levoglucosan, an anhydrosugar is formed while the combustion of lignin results in the formation of phenolic compounds like vanillic acid, cinnamic acid, or p-hydroxybenzoic acid. While the lignin burning products provide important information on paleo-fire history, intact polymeric lignin offers a deeper insight into the type and abundance of vegetation. By alkaline oxidation, the polymeric lignin is degraded into the lignin oxidation products (LOP) and the ratios of these products are related to wooden and non-wooden, as well as angiosperm and gymnosperm vegetation.

In this work, an analytical approach is presented covering a variety of SOA markers, biomass burning markers, and polymeric lignin, using UHPLC-HRMS and an elaborate sample preparation procedure. The method was applied to samples from Colle Gnifetti in the Swiss-Italian Alps, a part of Grenzgletscher, covering the time between 1920 and 1994. We present first data on polymeric lignin in ice core samples and an examination of correlations with known organic proxies to emphasize the relevance of lignin not only in climate archives like speleothems and sediments but also in ice core samples.
Eddies and the distribution of eddy kinetic energy in the Arctic Ocean
Authors: von Appen Wilken-Jon , Baumann Till , Janout Markus , Koldunov Nikolay , Lenn Yueng-Djern , Pickart Robert , Scott Robert , Wang Qiang
Published: March 2022

Mesoscale eddies are important for many aspects of the dynamics of the Arctic Ocean. These include the maintenance of the halocline and the Atlantic Water boundary current through lateral eddy fluxes, shelf-basin exchanges, transport of biological material and sea ice, and the modification of the sea-ice distribution. Here we review what is known about the mesoscale variability and its impacts in the Arctic Ocean in the context of an Arctic Ocean responding rapidly to climate change. In addition, we present the first quantification of eddy kinetic energy (EKE) from moored observations across the entire Arctic Ocean, which we compare to output from an eddy resolving numerical model. We show that EKE is largest in the northern Nordic Seas/Fram Strait and it is also elevated along the shelfbreak of the Arctic Circumpolar Boundary Current, especially in the Beaufort Sea. In the central basins it is 100-1000 times lower. Except for the region affected by southward sea-ice export south of Fram Strait, EKE is stronger when sea-ice concentration is low compared to dense ice cover. Areas where conditions typical in the Atlantic and Pacific prevail will increase. Hence, we conclude that the future Arctic Ocean will feature more energetic mesoscale variability.
Fine structure of the Suigetsu atmospheric 14C record 10-27 cal. ka turns out as authentic base for improved global correlation of 14C-dated planktic records of ocean climate
Authors: Sarnthein Michael , Grootes Pieter M.
Published: March 2022

The fine structure of the Suigetsu-based atmospheric 14C age plateaus (14C age changes little with time) and jumps (14C age changes faster than real time) provides a suite of authentic structures between 10 and 27 cal. ka. They can be identified by various independent techniques, such as visual inspection, the 1st derivative of 14C ages against time, and a Bayesian spline of 14C concentrations against time. The global significance of these structures, after a time scale update by Bronk Ramsey et al. (2020) and minor adjustments, is shown by the coherence with pertinent structures in the tree ring record 10 to ~15 cal. ka. The millennial-to-centennial-scale atmospheric 14C fluctuations influence local surface-ocean 14C concentrations and may be recovered from high-resolution planktic sediment records around the world ocean, despite various processes that lead to partial distortion of a sediment record. The Suigetsu suite of atmospheric 14C structures, identified in high-resolution planktic sediment records, thus may serve as a unique tool for global stratigraphic correlation and improved dating of paleoceanographic records, independent of local marine reservoir effects (Sarnthein et al., 2020).

Bronk Ramsey et al. (2020), Radiocarbon 62/4, https://doi.org/10.1017/RDC.2020.18,

Sarnthein et al. (2020), Climate Past 16, https://doi: 10.5194/cp-16-2547-2020,
The Oceanographer transform fault revisited – preliminary results from a micro-seismicity survey reveals extensional tectonics at ridge-transform intersections
Authors: Grevemeyer Ingo , Lange Dietrich , Klaucke Ingo , Beniest Anouk , Gómez de la Peña Laura , Ren Yu , Hilbert Helene-Sophie , Li Yuhan , Murray-Bergquist Louisa , Unger Katharina , Devey Colin W. , Ruepke Lars
Published: March 2022

Fracture zones were recognized to be an integral part of the seabed long before plate tectonics was established. Later, plate tectonics linked fracture zones to oceanic transform faults, suggesting that they are the inactive and hence fossil trace of transforms. Yet, scientist have spent little time surveying them in much detail over the last three decades. Recent evidence (Grevemeyer, I., Rüpke, L.H., Morgan, J.P., Iyer, K, and Devey, C.W., 2021, Extensional tectonics and two-stage crustal accretion at oceanic transform faults, Nature, 591, 402–407, doi:10.1038/s41586-021-03278-9) suggests that the traditional concept of transform faults as being conservative (non-accretionary) plate boundary faults might be wrong. Instead, transform faults are always deeper than the associated fracture zones and numerical modelling results suggest that transform faults seem to suffer from extensional tectonics below their strike-slip surface fault zone. During the cruise M170 of the German research vessel METEOR early in 2021, we aimed to test this hypothesis by collecting, in a pilot study, micro-seismicity data from the Oceanographer transform fault which offsets the Mid-Atlantic Ridge by 120-km south of the Azores near 35°N. Preliminary analysis of 10-days of seismicity data recorded at 26 ocean-bottom-seismometers and hydrophones showed 10-15 local earthquakes per day. Along the transform fault the distribution of micro-earthquakes and focal mechanisms support strike-slip motion. However, at both ridge-transform intersections seismicity does not mimic a right-angular plate boundary; instead, seismicity occurs below the inside corner and focal mechanism indicate extensional tectonics. Therefore, micro-seismicity supports features found in numerical simulations, revealing that transform faults have an extensional as well as a strike-slip component.
Fault tectonic analysis of focal mechanism data of aftershocks of 2017 Pohang, Korea, earthquake of Mw = 5.4: Stress layering phenomenon between Himalayan and Philippine Sea tectonic domains
Authors: Choi Pom-yong , Son Minkyung , Choi Jin Hyuck
Published: March 2022

In November 2017, an Mw 5.4 earthquake with a shallow (~ 4 km) hypocenter occurred in Pohang, South Korea. Seismotectonics of this region is highlighted by ENE-WSW compression, the dominant stress field in the Korean peninsula, belongs to the Himalayan tectonic domain (HTD), and WNW-ESE or NW-SE compression belongs to the Philippine Sea tectonic domain (PSTD). Here we analyzed the aftershocks, involving focal mechanism of 38 events, to understand the characteristics of the earthquake sequence. Our results show that the mainshock sequence occurred on four ruptures showing a NE-SW trend and in February 2018, one another earthquake (or aftershock) occurred on a NNW-SSE trending rupture at 3.5 km west of the epicenter of the mainshock. Note that aftershocks mainly occurred between two NNE-SSW trending faults: Seonggok Fault and Gokgang Fault.

We analyzed the focal mechanism data as done by fault tectonic analysis. We classified them into several clusters following locations and depths and by whether a population shows a strike-slip faulting type or reverse faulting type. They were classified into several different clusters in the central main area, the northeastern area, and the southwestern area. In the central main area, focal mechanism data of strike-slip faulting type show that the WNW-ESE compression prevails in the depth between 2.0 to 4.0 km and 5.6 to 5.8km, while ENE-WSW compression is dominant between 4.3 and 5.0 km. Those of reverse faulting type display the ENE-WSW compression between 4.7 and 5.7 km deep. This implies that the intermediate depth was affected by the HTD and the upper and lower depths by the PSDT, showing a kind of stress layering.

In the northeastern area, roughly E-W compression prevails between 3.7 and 6.5 km deep, and NW-SE compression between 6.0 and 6.7 km deep. In the southwestern area, roughly E-W compressions were induced in the depth of 4.0 to 5.0 km. E-W compression seems to belong to the combinatory stress state of the HTD and PSTD, and NW-SE compression in the lower part might belong to the stress of PSDT.

The phenomenon of stress layering during the Pohang earthquake reveals that the intervention between the HDT and PSDT resulted in the mainshock and aftershocks of 2017 Pohang earthquake, as in the 2016 Kumamoto, Japan, earthquake.
Kyrill, Franz, and the Societal Impacts of the Storms of January 2007
Authors: Kettle Anthony
Published: March 2022

January 2007 was a remarkably stormy period in Europe with impacts on societal infrastructure and implications for energy meteorology.  A series of cyclones tracked across the North Atlantic and into Europe during the two week period 8-22 January 2007.  For many parts of Europe, Storm Kyrill on 18 January 2007 was the most important of these for the infrastructure damage that it caused.  It had the highest European storm-related insurance losses in recent history.  The storm spawned a high intensity derecho that started in western Germany and travelled into eastern Europe. It was associated with severe convection, lightning, several tornadoes, and strong wind gusts.  The storm caused over 50 fatalities, widespread disruption of transport and power networks, and a lot of forest damage.   Storm Hanno on the 14 January 2007 was the second most severe storm of the period with serious impacts in Norway and southern Sweden.  Wind gusts reached the level of the 20-50 year event.  There were 6 fatalities in southern Sweden, some building damage, power cuts, and forest damage.  Storm Franz on 12 January 2007 caused the highest surge in the southern North Sea for January.  However, its flooding impact was reduced because the monthly cycle of spring and neap tides was near a minimum.  By contrast, astronomical tides were highest near the end of the period on 20-22 January 2007.  The highest absolute water levels for the month for many tide gauge stations were registered during Storm Kyrill on 18 January 2007 and also during Storm Lancelot on 20 January 2007.  This contribution takes a closer look at the North Sea surge of two important storms of the period: Storm Franz and Storm Kyrill.  An analysis is presented of tide gauge data to elucidate the storm surge and wave field around the North Sea and to assess possible links with shipping accidents and offshore incidents.  An unusually large wave sequence had been registered at the FINO1 offshore wind energy research platform only a couple of months previously on 1 November 2006.  The water level data is analyzed to ascertain if there may have been a repeat of the wave event during the storm sequence on 8-22 January 2007.
Nanoparticles formed during mineral-fluid interactions
Authors: Putnis Christine V. , Ruiz-Agudo Encarnación
Published: March 2022

Mineral-fluid replacement reactions occur ubiquitously throughout the crust of the Earth, often resulting in the formation of nanoparticles. Recent research highlights the formation of nanoparticles1, especially in the light of mineral/crystal growth by non-classical growth mechanisms, whereby solids form from prenucleation species or clusters within an aqueous solution from which solid nanoparticles precipitate. This is very often related to the dissolution of an existing mineral/solid phase that is coupled at the mineral-fluid interface with the precipitation of a new more stable phase2. This process will occur wherever aqueous fluids can penetrate and react with constituent minerals of a rock, that is, along fractures, grain boundaries and initial or reaction-induced interconnected porosity, all potential pathways for fluid-mediated reactions. Examples given here highlight fluid pathways and subsequent nanoparticle formation, an understanding of which can be useful for potential environmental remediation strategies, such as carbon mineralization and toxic element sequestration. Recent advances in analytical techniques, such as advances in atomic force microscopy, advanced scanning and transmission microscopies, are enabling the imaging of nanoparticles. Examples presented illustrate the conditions under which nanoparticles form during the coupling of dissolution and precipitation and enable a better understanding of the mechanisms that drive fluid-mineral reactions.

References

1Putnis C.V. and Ruiz-Agudo E. 2021. Nanoparticles formed during mineral-fluid interactions. Chem. Geol. 586, 120614.

2Ruiz-Agudo E., Putnis C.V., Putnis A. 2014. Coupled dissolution and precipitation at mineral-fluid interfaces. Chem. Geol., 383, 132-146.
Increasing surface runoff from Greenland's firn areas
Authors: Tedstone Andrew , Machguth Horst
Published: March 2022

Most of the Greenland ice sheet (∼78% to 92%) is underlain by porous snow and firn, into which meltwater can percolate and refreeze, or run off. However, the fate of meltwater in firn areas is poorly constrained. We identified the ice sheet’s annual visible runoff limits by mapping surface hydrological features in >25,000 Landsat satellite scenes. Between 1985–1992 and 2013–2020, the visible runoff limits along the west and north margins rose by 58–329 metres, expanding the visible runoff area by ~29%. Estimates using two different regional climate models suggest that the enlarged area has contributed from 190–264 Gt to 320–491 Gt of runoff since 1985, equivalent to as much as ∼10% of recent annual runoff from the west and north margins. However, the spread highlights that runoff processes in the percolation zone are a source of considerable uncertainty among the major models. We demonstrate that sustained excess melting since the 1990s has provided favourable conditions for anomalous near-surface firn densification. Much of the expanded visible runoff area is underlain by relatively impermeable and persistent ice slabs that have previously been identified by airborne radar campaigns. These slabs have recently enabled sustained runoff from higher elevations even in cooler summers. Our findings highlight that lateral runoff over densified near-surface firn is pervasive in several sectors of the ice sheet and therefore must be incorporated into future runoff projections.
Impact of Climate Change on Landslide Susceptibility – for the Case in Taiwan
Authors: Shou Keh-Jian
Published: March 2022

Due to the impact of climate change, the increasing frequency of extreme rainfall events, with concentrated rainfalls, commonly cause landslide hazard in the mountain areas of Taiwan. Although the extraordinary rainfall behavior is critical for the geohazard, it is significantly affected by the factors such as topography, the route of typhoon, etc. Therefore, there are uncertainties for the predicted rainfall as well as the landslide susceptibilities.

This study employs rainfall frequency analysis together with the atmospheric general circulation model (AGCM) downscaling estimation to understand the temporal rainfall trends, distributions, and intensities in the adopted study area in Central Taiwan. The uncertainties within the rainfall prediction was investigated before applied to the landslide susceptibility analysis. The catchments in Taiwan, including Tachia River, Wu River, and Chuoshui River, were adopted as the study area. To assess the hazard of the landslides, logistic regression methods and supporting vector machines method were applied, in which the control factors were analyzed and discussed. The results of predictive analysis with the consideration of uncertainties can be applied for risk prevention and management in the study area.
Was the 2020 Lake Victoria flooding linked to anthropogenic climate change? An event attribution study
Authors: Pietroiusti Rosa , Vanderkelen Inne , Thiery Wim
Published: March 2022

Heavy rainfall in East Africa between late 2019 and mid 2020 caused devastating floods and landslides throughout the region. These rains drove the level of Lake Victoria to a record-breaking maximum in the second half of May 2020, when the lake reached its highest level since measurements began in 1948. The high lake levels and consequent shoreline flooding triggered international attention, with media sources proposing a causal link with climate change. However, a formal attribution study identifying the possible role of anthropogenic climate change in increasing the likelihood of such record-breaking water levels has not been carried out so far.

We present an attribution study that estimates how anthropogenic climate change influenced the likelihood of observing the rate of change in Lake Victoria’s level that was recorded in 2020. To this end, we reconstruct the record-high lake level using an observational water balance model for Lake Victoria. We first investigate the influence of the different water balance terms on the resulting lake level. Then, we apply the water balance model in a probabilistic event attribution framework by forcing it with historical and natural forcing only (hist-nat) bias-adjusted precipitation from six Earth system models from the Coupled Model Intercomparison Project phase 6 (CMIP6) ensemble, as made available through the Inter-Sectoral Impact Model Intercomparison Project phase 3b (ISIMIP3b). The study contributes to a better understanding of impacts caused by climate and weather extremes in the Greater Horn of Africa by disentangling the role of anthropogenic climate change and natural internal variability in a high-impact flood event.
Stratospheric moistening after 2000
Authors: Konopka Paul , Tao Mengchu , Ploeger Felix , Hurst Dale F. , Santee Michelle L. , Riese Martin
Published: March 2022

The significant climate feedback of stratospheric water vapor (SWV) necessitates quantification of changes in the SWV budget. Model simulations driven by the newest ECMWF reanalysis ERA5,  satellite observations from the Microwave Limb Sounder (MLS) and in-situ frost point hygrometer observations from Boulder consistently show substantial stratospheric moistening  after the year 2000, following a drop in water vapor at the turn of the millenium.  The time evolution of the simulated SWV anomalies is in excellent agreement with that derived from MLS.  We find strong positive SVW trends in the Northern Hemisphere and weakly negative trends over the South Pole, mainly during austral winter. Moistening of the tropical stratosphere after 2000 occurs mainly during late boreal winter/spring, reaches values of ∼0.2 ppm/decade, is well correlated with a warming of the cold point tropopause by ∼0.4 K/decade and is partially caused by volcanic eruptions and ENSO.
Fluid-rock reaction mechanisms and the inevitable consequences for mass transport and texture formation.
Authors: Putnis Andrew , Moore Jo , Austrheim Håkon
Published: March 2022

It is well-established that the mechanism of re-equilibration of a mineral assemblage at temperatures where the spatial scale of solid-state diffusion is restricted to intra-crystalline processes, is by dissolution-transport-precipitation. When the dissolution and precipitation steps are spatially coupled, pseudomorphic mineral replacement, in the absence of deformation, is a common observation in both nature and experiment. External stress appears to uncouple the dissolution and precipitation steps, inevitably leading to mass transport and dissolution-precipitation creep as the dominant deformation mechanism. The precipitation process involves nucleation and, in deforming rocks, the minimisation of surface energy leads towards textural equilibration and metamorphic differentiation. The overall process can be considered as a sequence of recrystallisation steps that lead to minimisation of chemical and textural components of the overall free energy. Examples will be given from metamorphic reactions, diagenesis and sub-solidus texture formation in igneous rocks.
Exploring the sensitivity of modelled sea-level rise projections from the Amundsen Sea Embayment of the Antarctic Ice Sheet to model parameters
Authors: Bevan Suzanne , Cornford Stephen , Luckman Adrian , Hogg Anna , Otosaka Inés , Surawy-Stepney Trystan
Published: March 2022

Recent sea-level rise from the Antarctic icesheet has been dominated by contributions from Pine Island and Thwaites Glaciers of the Amundsen Sea Embayment (ASE). Much of the ASE ice is grounded below sea level and is therefore likely to be highly sensitive to ongoing oceanic and atmospheric warming.

Confidence in model-based predictions of the future contributions of the ASE region to sea-level rise requires an understanding of the sensitivity of the predictions to input data, such as bedrock topography, and to chosen parameters within, for example, sliding laws.

We will present results from using the BISICLES adaptive mesh refinement ice-sheet model to explore the sensitivity of modelled ASE 2050 grounded ice loss. We test a regularized Coulomb friction sliding law, varying the regularization parameter, and we test the sensitivity to bedrock elevation by adding gaussian noise of different wavelengths to MEaSUREs BedMachine Version 2 elevations. However, within our experiments, we find the greatest sensitivity in modelled 2050 sea-level contributions is to the imposed ice-shelf thinning or damage rates, which we vary between spatially uniform values of 0 to 15 m/year.

We will also present a comparison of the modelled annual evolution of surface velocity and surface elevation change with observations. Observed surface velocities are based on Sentinel 1 feature tracking, and surface elevation change rates are derived from satellite radar altimetry.
Microscale deformation in a compacted and anisotropic mudstone: the Opalinus Clay, northern Switzerland
Authors: Akker Ismay Vénice , Herwegh Marco , Aschwanden Lukas , Mazurek Martin , Madritsch Herfried
Published: March 2022

The low permeability and excellent sealing properties of mudstones places such sedimentary rocks into focus of geo-engineering applications using clay formations as natural barriers for contaminant transport. Here we investigate microscale deformation structures in the Opalinus Clay in northern Switzerland, which is currently under investigation as a host rock for radioactive waste confinement. We aim to characterize paleo-faulting/fracturing as well as subsequent mineralization events. For this purpose, drill core samples were investigated macroscopically, as well as by low and high-resolution optical light microscopy and scanning electron microscopy (SEM) in combination with energy-dispersive X-ray spectroscopy (EDX). These data were combined with high-resolution trace element maps obtained by Synchrotron X-ray Fluorescence Microscopy (SXFM). By combining the observed microstructures with the micro-chemistry of the associated mineralization events we yield a grouping between different processes and, in combination with cross-cutting relationships, a relative timing of the different deformation events.

Commonly the Opalinus Clay is weakly deformed, with only few localized deformation structures. The latter include: calcite veins (mm thickness) as well as mineralized (calcite and celestite) thrusts, normal faults and strike-slip faults (all cm thickness). Micro-textural analysis shows that low-angle thrust faults with calcite slickensides on their dip-slip surfaces localize on pre-existing horizontal fibrous calcite veins. The horizontal veins imply an early deformation stage with temporarily high pore fluid pressures under sub-horizontal max. principle stresses within the highly anisotropic mudstone. The first order analysis of the major element chemistry between the calcite forming slickensides and the fibrous veins shows significant differences in Mg, Fe and Mn contents. From a fluid-mechanical perspective, this finding implies that generation of fibrous veins during a first fluid event provides the mechanical discontinuity, which is reused during later fluid assisted thrusting.

The overprinting relationships between fibrous veins and slickensides indicate that deformation/precipitation events occurred in a cyclic fashion. Such information is a key towards the understanding of fluid assisted deformation and mineralization processes in compacted and anisotropic clay formations. On a regional scale, variations in paleo-deformation-mineralization events in the Opalinus Clay imply regional differences likely related to a gradually varying intensity of compressional (thrusting) and extensional (normal faulting) tectonics throughout northern Switzerland.