bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation analysis of the change law of index gas and active functional groups in the process of high-temperature spontaneous combustion of minerals in the Fushun West Mine.
Authors: Chang Jia-Ming , Zhao Jing-Yu , Song Jia-Jia , Zhang Ting-Hao , Hang Gai , Chi Zhao-Long , Wang Chen
Published: February 2023

The spontaneous combustion of underground minerals causes huge property losses and ecological damage. Coal and oil shale are co associated minerals in the Fushun West Mine, and both have the ability of oxidative spontaneous combustion. To study the effect of microstructure changes on the macroscopic gas product concentration during the mineral oxidation spontaneous combustion process in the Fushun West Mine, this study used a high-temperature temperature-programmed test to obtain the change trend of gas product concentration in different oxidation stages of minerals. Using Fourier transform infrared spectroscopy (FTIR) technology, the changes in active functional groups of surface molecules during the process of mineral oxidation and spontaneous combustion were identified. Finally, using the gray correlation degree, correlation analysis between the concentration of gas products and the concentration of active functional groups in different oxidation stages was carried out. The key reactive functional groups affecting mineral spontaneous combustion were identified. The essential reason for the change in the gas product was revealed.
Hydroacoustic monitoring of Mayotte underwater volcanic eruption
Authors: Lavayssière Aude , Bazin Sara , Royer Jean-Yves , Raumer Pierre-Yves
Published: February 2023

Mooring networks of hydrophones is an effective way to monitor the ocean soundscape and its sources, and it is particularly efficient to better understand underwater volcanic eruptions. In October 2020, four continuous hydrophones were moored in the SOFAR channel around Mayotte Island, in the North Mozambique Channel, to monitor the Fani Maoré 2018-2022 submarine eruption. This eruption created a new underwater seamount at 3500 m below sea level, 50 km east of Mayotte. Since 2020, the MAHY hydrophones record sounds generated by the volcanic activity and the first results have evidenced earthquakes, underwater landslides, and impulsive signals that we related to steam bursts during lava flow emplacement. An automatic detection of these specific impulsive signals is being developed for a better monitoring but also a better understanding of their source. The hydroacoustic catalog obtained characterize the Mayotte lava flow activity and will help quantify the risk for Mayotte population. This detection could be used by Mayotte’s and other volcano observatories to monitor active submarine eruptions in the absence of regular seafloor imaging.
Save the glaciers! An educational escape kit
Authors: Chapuis Anne , Burgard Clara , Ducasse Etienne , Cook Samuel , Gauthier Léna , Garcia Molina Cruz , Bataille Amélie , Durand Gaël
Published: February 2023

Save the glaciers! is an educational escape kit designed for teenagers (11-18 years old) to learn what glaciers are, how they move, how they react to climate change and what people can do to slow down their melt.We made two versions of the game: a physical version and an online version. In both versions players have to sequentially solve 4 enigmas to unlock the next enigma until they reach the end of the game. Each enigma is designed to make the player discover and understand the following processes:
Melting of mountains glaciers contributes to sea level rise

Anatomy and mass-balance of a mountain glacier: What is it made of? How does it form? How does it grow and shrink?

Glacier sliding: glaciers are not static, they slowly slide under their own weight

Mountain glaciers are losing mass all around the world due to climate change, which can be observed by looking at their retreating termini.

The physical version is designed to be played by 5 people; the online version can be played alone. Three levels of difficulty have been designed for the physical game: secondary-school pupils, high-school pupils and university students. In total more than 200 people have played the game, across both the physical and online versions.The game has been developed as a collaboration between the H2020 project PROTECT and a team at the Institute of Environmental Geosciences.
Future projections of wind energy capacity factors over Europe using CMIP
Authors: Mostue Idunn Aamnes , Zeyringer Marianne , Storelvmo Trude , Ruiz Baños David
Published: February 2023

In a rapidly changing climate, changes in the frequency and intensity of future extreme weather events is expected to pose complex impact on futureweather-dependent energy systems. The contribution by Working Group I to the latest IPCC report (AR6) includes for the first time a dedicated chapteron weather extremes. It demonstrates that even relatively small incremental increases in global mean temperature (+0.5◦C) cause statistically significantchanges in extremes on the global scale and for large regions. In 2021, Europe experienced the worst wind drought in 60 years, followed by extreme heatwave episodes and a national daily maximum temperature record of 40.3◦C in the UK in 2022.The transition of the energy sector to renewable energy is key to reach the Paris Agreement goal of limiting global warming, but this also increases the energy sector’s exposure to future weather extremes in a changing climate. The impacts of climate variability and climate change on present and near future national energy systems are increasingly well documented within the literature. However, within this interdisciplinary field of research there has been little attention on impacts of extreme weather events on the energy system operations. Modellers usually use historic weather data and therefore do not consider ”new” extreme weather risks, posing problems on both the operational and infrastructural side. Omitting those risks can lead to designing systems that are operationally inadequate, i.e. prone to (long) power outages leading to major social, economic and health consequences.The present work aims to study the variability of renewable energy generation for weather years under different future climates over Europe. We will use different future climate scenarios from the Coupled Model Intercomparison Project 6th Phase (CMIP6), to assess future projections of wind energy capacity factors. The global datasets of climate data will be adapted for Europe where we will interpolate the wind speed based on model-level raw data and further create energy capacity factors. We expect this study to be a first step in exploring the future changes in and occurrences of extreme weather events, and how these will impact the generation of renewable energy over Europe. This will in turn contribute to the knowledge on how we can plan for climate resilient renewable energy systems robust to future extreme weather events over Europe.
The relationship between surface tension and atmospheric ice-nucleating activity of agricultural soil
Authors: Thompson Kathleen , Link Nicole , Murray Benjamin , Borduas-Dedekind Nadine
Published: February 2023

Ice-nucleating particles (or INP) play an important role in controlling cloud radiative properties and lifetimes. Therefore, understanding the sources and mechanisms of ice formation in clouds is vital for understanding their impact on cloud radiative feedback. Agricultural dust contributes 25% of global dust emissions and has been shown to nucleate ice at temperatures up to -6°C. This high nucleating ability of agricultural soils suggests that they may be an essential source of INPs on regional or global scales. Many organic components, which have been shown to be important for ice nucleation in soils, have surface active properties that may enhance the ice-nucleating ability of the soil. In this work, lignin was used as a reference for investigating surfactant macromolecules as a potential component of ice nucleation. Lignin solutions showed high ice-nucleating activity in line with decreases in surface tension. We contrasted our observations of lignin with observations from soil extractions from samples taken in the field. Preliminary results suggest little correlation between surface tension measurements and the ice-nucleating activity of extracted soil samples. The presence of a correlation between ice-nucleating and surface activity in soil components such as lignin, but the absence of this correlation in complete soil samples suggests that surfactants can be important ice-nucleating macromolecules, but that highly active soil samples do not necessarily reduce the surface tension at the water-air interface.
European S2S streamflow forecasting: Towards a seamless communication
Authors: Pechlivanidis Ilias , Crochemore Louise
Published: February 2023

Information at the sub-seasonal to seasonal (S2S) time scale can be of high socio-economic value to a variety of users whose decision-making depends on climate variability. The usability of S2S forecasts generated by Numerical Weather Prediction (NWP) systems has increased over the years not only due to their skill improvement but also due to their potential to bridge the medium-range and seasonal horizons. The skill of the sub-seasonal (4-6 weeks ahead) and seasonal (6-12 months ahead) NWP-based forecasts in space and time depends on different factors, including the representation of the physical process, the initialization frequency and the spatial resolution. However, the NWP model setups differ between the two time horizons, and this consequently intrinsic differences between the two forecast products. To date, it has been subjectively accepted that during the first time horizons, e.g. up to 6 weeks ahead, the sub-seasonal forecasts are more informative than the seasonal forecasts, and hence all efforts on generating a seamless product are implemented through a direct merging of the two products. This unfortunately masks the potential for tailored seamless products that extract the best S2S information available.Here, we evaluate the S2S hydro-meteorological forecasts from the ECMWF sub-seasonal (ENS-ER) and seasonal (SEAS5) products, aiming to identify their skill complementarity in space and time and further seamlessly communicate them for improved decision-making. Both the ENS-ER and the SEAS5 precipitation and temperature forecasts were bias-adjusted prior to forcing the E-HYPE hydrological model. The investigation focuses on the period 1999-2015. Overall, results highlight both spatial and temporal complementarities between the two systems, which is very encouraging for a seamless communication. In particular, ENS-ER-based hydro-meteorological forecast skill patterns appear to be more homogeneous spatially, while SEAS5-based forecasts ensure skill at longer forecast horizons. This diagnostic analysis is a step forward in hydro-climate services, indicating the tipping points in all European river systems for switching from ENS-ER to SEAS5 forecasts.
Application of AHP in flood combination calculation of check dam system
Authors: Gui Lili , Wang Zhijian
Published: February 2023

Check dam is an important water and soil conservation measure for comprehensive treatment of small watershed in the Loess Plateau. The reinforcement of sick and dangerous check dam is an important measure to ensure the safe operation of check dam and promote the high-quality development of the Yellow River basin. How to scientifically and reasonably determine the flood control standard of each dam and do a good job in flood combination and hydrological calculation is a key technical problem to be solved in the reinforcement design of check dam system engineering. Taking the dam system project of Wan'angou small watershed in Shanxi Linxian County as an example, the overall layout of the dam system project is shown in Fig.1. Based on the relevant theory of "AHP", starting from the upstream of the main and branch ditches in the basin, comprehensively analyze the distribution location of each dam and its impact on the downstream, construct the hierarchical structure model of large and medium-sized silting dams in the dam system, as shown in Fig. 2, from which the distribution characteristics of the dam system in the basin and the correlation between the upstream and downstream dams can be intuitively and quickly analyzed, and on this basis, determine the flood control standard, flood combination and hydrological calculation of each dam. It can be seen intuitively in Fig. 2 that during the design of danger removal and reinforcement, the check dam and the reasons for the improvement of flood control standards need to be improved. For example, two large (1) check dams GZ4* and GZ5* in level 1, first because there are residential areas in the downstream influence area, the flood control standards are increased to large (2) check dams DZ4* and DZ5* according to the specification requirements; Secondly, since its downstream is the large (1)check dam G1 in level 2, considering the flood combination, it is raised to the large (1) check dam GZ4* and GZ5*. At the same time, from Fig.2, it can be determined that the flood combination is analyzed and the hydrological calculation is carried out according to the three conditions of single dam, series dam and parallel dam, for example, the large (1) check dam GD6 in level 5 is calculated according to three parallel check dams.
Study of multiple ELVES at the Pierre Auger Observatory
Authors: Vásquez Ramírez Adriana , Mussa Roberto , Núñez Luis A. ,   Pierre Auger Collaboration
Published: February 2023

ELVES are transient ring-shaped emissions occurring in the ionosphere above thunderstorms. Multi-ELVES are events consisting of two and up to four rings of light separated temporally by tens of microseconds. The Fluorescence Detector (FD) at the Pierre Auger Observatory has been detecting ELVES with a dedicated trigger since 2013. The high temporal resolution of 100 ns of the FD allows us to record the phototraces of the events in great detail. From the improved processing of the phototraces, we have observed ELVES with double and triple peaks. In fact, during the period 2014-20, about 27% of the events detected at Auger are multi-ELVES. The origin of multi-ELVES is still not fully understood, therefore in this work, we tested two models: the first one relates the temporal difference between two peaks (ΔT) to the rise (tr) and fall (tf) times of the current density pulse of the source beam; the second one relates the height of the intra-cloud lightning source (hb) to ΔT and is used to study events with three or more peaks. From the first model, we can obtain combinations of tr and tf where ΔT tends to zero, i.e. the origin of the simple ELVES can also be explained. For this analysis, we compare the ELVES parameters measured in Auger with the lightning properties detected by Earth Networks, i.e. the location, waveform, and height of these sources. 
Upper-plate shortening and Andean-type mountain-building in the context of mantle-driven oceanic subduction
Authors: Lacassin Robin , Habel Tania , Replumaz Anne , Guillaume Benjamin , Simoes Martine , Geffroy Thomas , Kermarrec Jean-Jacques
Published: February 2023

To explore the conditions that lead to mountain-building in the case of an oceanic subduction, we conduct analog experiments (with silicon putty upper and lower plates, glucose syrup upper mantle) where subduction is driven by slab pull but also by an underlying mantle flow. Here, plate displacement is not imposed as in most models, but is controlled by the overall balance of forces in the system. We simulate three scenarios: no mantle flow (slab-pull driven subduction), mantle flow directed toward the subducting plate, and mantle flow directed toward the overriding plate. In the case of this latter scenario, we also test the influence of pre-existing rheological contrasts in the upper plate to best reproduce natural cases where inheritance is common. Our experiments show that when plate convergence is also driven by a background mantle flow, the continental plate deforms with significant trench-orthogonal shortening (up to 30% after 60 Myr), generally associated with thickening. We further identify that upper plate shortening and thickening is best promoted when the mantle flow is directed toward the fixed overriding continental plate. The strength of the upper plate is also a key factor controlling the amount and rates of accommodated shortening. Deformation rates increase linearly with decreasing bulk strength of the upper plate, and deformation is mostly localized where viscosity and strength are lower. When compared to the particular natural case of the Andes, our experiments provide key insights into the geodynamic conditions that lead to the building of this Cordilleran orogen since the Late Cretaceous - Early Cenozoic. 
Retrieval of the Vertical Profile of Atmospheric Optical Depth using Thermal Emission Spectrometer Visible and Infrared Bolometer observations
Authors: Mason Emily L. , Smith Michael , Wolff Michael , McConnochie Timothy
Published: February 2023

The Mars Global Surveyor (MGS) mission carried a spectrometer and bolometer as part of the Thermal Emission Spectrometer (TES) instrument package. While the spectrometer ceased operations in early Mars Year (MY) 37 due to aging of the required neon lamp, the bolometers continued to operate for nearly a full Mars year. This time-period covered the MY 27 dust storm season and most of the MY 28 aphelion cloud belt season. TES consisted of a spectrometer with two additional broadband bolometers in the visible (0.3-3.0 µm) and infrared (5-100 µm). Observations were taken with both the spectrometer and bolometer simultaneously for nearly three Mars years prior to degradation of the neon lamp. The observational cadence during the bolometer-only extended mission alternated between one orbit of nadir observations and one orbit of limb observations. We will present results for the vertical distribution of atmospheric aerosol optical depth retrieved from the TES bolometer limb observations prior to the extended mission when spectrometer data (and previous retrievals) are available to inform the results. In addition, we will provide examples of retrieved vertical distribution of aerosol optical depth for observations taken in the bolometer-only extended mission for comparison.
Developing a national-scale hydrological model for drought monitoring in Ireland
Authors: Vengana Sri , O'Loughlin Fiachra
Published: February 2023

Ireland’s climate is changing with the same pattern as global trends. This has the potential to have significant impacts on precipitation and water availability throughout the country. It is vital to be able to quantify the size of these impacts. One way to do this is by hydrological models tuned for the extremes of interest. This study focuses on the development of a national scale hydrological model calibrated for droughts and low flows across Ireland. A total of 332 catchments have been used to calibrate and validate the national scale model hydrological model using the Modular Assessment of Rainfall-Runoff Models toolbox (MARRMoT) over the chosen 332 catchments. These catchments range in sizes (50km2 to 10,800 km2) and all chosen catchments have a minimum of 30 years of data available so that the model calibration and validation can be performed adequately. A few different objective functions focusing on droughts were used in calibration and validation including Kling and Gupta efficiency of discharge KGE(Q) function and logarithmic transformation based KGE. Initial results show that the simulated discharges can reproduce the observed discharges across the majority of catchments and that catchment size and the amount of baseflow are the important factors that influence the accuracy of the simulations.
Sedimentology and microbiology of Lake Sentani, Papua Province, Indonesia – A multidisciplinary study of a tropical lake system under increasing anthropogenic stress
Authors: Kallmeyer Jens , Nomosatryo Sulung , Henny Cynthia , Lipus Daniel , Schleicher Anja , Tjallingii Rik
Published: February 2023

Lake Sentani consists of  four interconnected sub-basins with different water depths and water column characteristics, ranging from fully mixed to permanently stratified. Its catchment is comprised of highly diverse lithologies, ranging from mafic and ultramafic rocks to clastic sediment and carbonates, so each sub-basin receives a distinct sediment input. Lake Sentani is also influenced by anthropogenic activity due to the growing population around the lake, potentially leading to local eutrophication. Due to its unique characteristics, we investigated the effects of catchment lithology and water column structure on sediment composition. We also investigated microbial community composition and diversity in surface sediments across Lake Sentani as well as in the partially ephemeral tributary rivers and the river mouths, which form the connection between riverine and the lacustrine habitats.Using multivariate statistical analyses of mineralogical and major element compositions obtained by X-ray diffraction (XRD) and X-ray Fluorescence (XRF) analyses we could identify three main types of sediment based on distinct compositional differences between rivers, shallow/proximal and deep/distal lake sediments. There is large spatial heterogeneity within the lake’s sub-basins that is mainly caused by catchment geology and topography, river runoff as well as bathymetry and the depth of the oxycline.The different sediment types are mainly characterized by the amounts of organic carbon (TOC) and sulfur as well as elements associated with siliciclastic rocks (Ti, Al, Si, K). Depending on the sedimentary environment, the redox-sensitive elements Fe and Mn change from a positive correlation with siliciclastic elements in river samples to a negative correlation in the lake.Using 16S rRNA based analyses to investigate microbial community structure and diversity, we detected highly diverse microbial communities across the different lake basins and catchment river sediments, suggesting a wide variety of biogeochemical processes taking place. The molecular biological data broadly agree with the sedimentological differentiation of the sediment into three major groups, but they also provide a different perspective on the biogeochemical processes in the lake. However, our study also suggested increased anthropogenic stressors impacting the microbial community, most probably caused by population growth and urbanization, especially along the northern and northeastern parts. River and river mouth sediments, particularly from these more urbanized areas, were enriched in microbial taxa frequently associated with eutrophication and affiliated with human waste and industrial pollution.Our study highlights the value of multi-disciplinary datasets for a holistic lake management under increasing anthropogenic stress.
Surface flow and ice rafting velocities during freezing and thawing periods of three northern rivers.
Authors: Takala Tuure , Lotsari Eliisa
Published: February 2023

In present climate, almost all rivers freeze in the northern high latitude regions every year. In the future, this annual freezing cycle may undergo major changes. These changes can already be observed in the current climate. The effects of climate change in cold climate areas are radical and will have a great impact on the environment: Changes in the ice formation, duration and break-up of river ice cover will affect the hydrology of the rivers. Effects will vary from flow rates to sediment transport and discharge levels. For the most part, studies of freezing and thawing have been carried out under laboratory conditions or are outnumbered by open-channel studies depicting river systems in warmer areas. More information on the processes of freezing and thawing and the effects this cycle has on river flow, and vice versa, is needed by monitoring natural sites. Consequently, this study seeks to respond to this lack research and process knowledge, and aims 1)  to examine, whether the freezing and thawing periods affect the river surface velocity and the spatial variations of speed in the partly frozen channel (and vice versa), 2) to detect the differences in the formation of ice, ice cover and the ice break-up between different type of river reaches, and 3) to examine differences in the freezing and thawing cycles and surface velocity connections in hydro-climatically different rivers. The study is conducted in three cold climate region study sites: Boreal and continental, meandering Koitajoki River (Finland), straight reach of more maritime Sävarå River, and sub-arctic Pulmanki River (straight reach of a meandering river). The data for the study has been collected between 2020-2022 using game camera images and videos with georeferenced targets. The velocity of river flow is analyzed with two different methods (STIV and PTV) from the videos. At the same time, efforts will be made to compare how well the different methods work to analyze the situation in question. Reference measurements have also been carried out in the autumn before freezing, in winter during ice cover, and in spring after the break-up of ice, and these measurements are compared with the results of the analyses. The change and duration of the ice cover is analyzed based on the image series. Regional climate data, as well as data collected from research areas (water temperature, air temperature, atmospheric pressure) is used to estimate the winter conditions. In addition for new knowledge of freezing and thawing processes within cold climate region rivers, the results from this study enable advancing hydraulic modelling approaches in ice covered season, and further specify our knowledge on freezing and thawing of river ice.
Un-pinning of Antarctic ice shelves over the past 5 decades
Authors: Miles Bertie , Bingham Robert
Published: February 2023

Pinning points form when floating ice shelves locally reground on bathymetric highs. The anchoring of ice shelves onto these pinning points buttresses ice flow from the interior of the ice sheet, meaning they play a vital role in the mass balance of the ice sheet. However, we do not know how the hundreds of pinning points that fringe the Antarctic coastline have changed over recent decades. By utilizing the historic Landsat satellite image archive, we show that there has been an acceleration in pinning point loss over the past 5 decades, and in doing so help resolve the timeline of the onset of widespread ice shelf thinning in Antarctica. Between 1974 and 1990, only ice shelves in isolated regions were thinning and unanchoring from their pinning points, with 11% of all mapped pinning points reducing in size. Pinning point loss spreads from these isolated regions in the 1990s, with the proportion of pinning points reducing in size across the ice sheet more than doubles to 23%, before further increasing to 35% between 2000 and 2022. Pinning point loss is concentrated along the western Antarctic Peninsula, West Antarctic and Wilkes Land coastlines, but we do also observe the rapid growth and break-up of some large ice rises outside of these regions. Continued acceleration in pinning point loss will reduce the buttressing potential of ice shelves and ultimately result in enhanced discharge of ice into the Southern Ocean and contribute to sea level rise.
Evaluation on CMIP6 Global Climate Model Simulation of the AnnualMean Daily Maximum and Minimum Air Temperature in China
Authors: Xie Wenqiang , Yan Xiaodong
Published: February 2023

Simulations for China’s annual average maximum and minimum surface air temperature by CMIP6 models were evaluated, referring to observations from CN05.1. Results show that the annual average maximum and minimum surface air temperature in China from 1961 to 2014 had increasing trends. The maximum surface air temperature increased at a rate of 2.15 ℃/100 a. The growth rate of the minimum air temperature was 3.92 °C/100 a, which was about twice the growth rate of the maximum air temperature. CMIP6 models can simulate trends over long time scales, but there were large differences in the simulation ability of different models. The dispersion between models reached 0.38 °C/100 a (maximum air temperature) and 0.41 °C/100 a (minimum air temperature). BCC-ESM1 and EC-Earth3 had the best performance in simulating the trends of the maximum and minimum air temperature, respectively. CMIP6 models can well simulate the spatial distribution of the climatological maximum and minimum air temperature in China. Proportions of grid points where most of the model simulations correlated positively with observations were 82% (maximum air temperature) and 97% (minimum air temperature) in China. Simulation results of the maximum and minimum air temperature in the whole of eastern China had obvious geographical characteristics with a standard deviation within 3 ℃, showing a high consistency. The variation was significant in the western region and reached more than 6 °C in the Tibetan Plateau. GISS-E2-1-G and MRI-ESM2-0 can well simulate the main EOF (empirical orthogonal function) modes and principal components of the maximum and minimum air temperature in China in 1961–2014. In summary, CMIP6 models can well simulate the spatial distribution of the climatological maximum and minimum air temperature and interannual trends of the maximum and minimum air temperature in China.
Co-occurring British flood-wind events (1980-2080): Their anatomy & drivers
Authors: Hillier John , Bloomfield Hannah , Garry Freya , Bates Paul , Shaffrey Len
Published: February 2023

In wintertime, infrastructure and property in NW Europe are threatened by multiple meteorological hazards, and it is increasingly apparent that these exacerbate risk by tending to co-occurring in events that last days to weeks. Impacted by Atlantic storms, Great Britain (GB) is a sentinel location for weather that later tracks into NW Europe.   A recent, dramatic storm sequence (Dudley, Eunice, Franklin) demonstrated the need for a multi-hazard view by bringing a mixture of damaging and disruptive extremes including extreme winds and flooding over 7-10 days in Feb 2022.

This work uses a stakeholder inspired, event-based approach to jointly consider these two hazards.  A wind event set (n = 3,426) is created from the 12km regional UK Climate projections (1981-1999, 2061-2079) to match previously created high-flow events (Griffin et al, 2023). Then, the two hazards’ time-series are merged using windows up to a maximum size (Δt = 1-180 days) positioned to maximize the size of the largest events’ impact. The benefits and limitations of this methodology are discussed, anatomy of storm sequences (Δt = 21 days) discussed, and potential drivers of co-occurrence in the multi-hazard sequences (e.g. jet stream position/strength) examined.
Deciphering earthquake source observations to motivate questions for physics-based models of earthquake simulation
Authors: Harrington Rebecca M. , Liu Yajing , Yu Hongyu , Verdecchia Alessandro , Kemna Kilian B. , Bocchini Gian Maria , Dielforder Armin , Roth Marco P. , Kirkpatrick James , Cochran Elizabeth S. , Chang Hilary , Abercrombie Rachel E.
Published: February 2023

Earthquake stress drop values estimated from ground-motion spectra commonly vary by several orders of magnitude, particularly for small earthquakes (~M < 3). Stress-drop values have been found to vary with faulting style, faulting type (intraplate, interplate), depth, and to exhibit differences between natural and induced earthquakes. Nevertheless, distinguishing uncertainties from real trends across data sets is challenging, in part due to the variation in methodological approaches and observational constraints. However, the proliferation of high-quality, dense seismic data in recent years has shown that at least some of the variability in stress drop values almost certainly reflects diversity in fault strength and geological conditions. Coupling well-constrained observations to a variety of modeling approaches will help uncover what controls earthquake rupture processes, but deconvolving observational constraints from real variation in rupture behavior is key.We present our stress drop estimates from data sets representing a wide range of fault loading conditions and geological environments, from interplate, intraslab and forearc subduction faults, to volcanic, intraplate, and human induced events. Stress-drop values range primarily between 1 – 100 MPa for events that meet the criteria for spectral-ratio analysis.  We present correlations of low relative stress drop values in areas of high seismic attenuation indicative of lower rock strength, and a slight correlation with depth that corresponds to modeled deviatoric stress values. We also show one notable subset of induced events near active injection wells that exhibit stress drop values of ~0.1 MPa and have distinctive low-frequency content. Their spatial distribution, waveform, and source spectral characteristics suggest either slower rupture, lower stress drop values, or a combination of both, and may represent part of the transition between aseismic and seismic slip. We show using a Large-n array that while stress drop values are roughly constant (within 2 orders of magnitude), estimates can vary by roughly 25% when station coverage is limited to 15 stations or less with a maximum azimuthal gap of 90°.  Our findings highlight the importance of using modeling approaches to explore relative influence of fault strength and methodological approaches in stress drop variation. In particular, models that incorporate both frictional and thermoelastic approaches may provide clues to the variability of conditions that can activate faults, both within stable sliding and seismic rupture conditions.

 

 

 

 
Impact of rupture complexity on seismic hazard: Case of the 2018 Mw7.5 Palu earthquake
Authors: Jiao Liqing , Wang Teng , Feng Guangcai , Tapponnier Paul , Simanjuntak Andrean V. H. , Chan Chung-Han
Published: February 2023

Rupture complexity results in difficulty in quantifying seismic hazards, such as the probability of an earthquake on multiple fault segments and spatial distribution of fault displacement on the surface. Here we tried to propose a dynamic model to fit the rupture behavior of the 2018 Mw7.5 Palu earthquake, which splays along several sub-fault plans on the surface. The Palu event was initiated on an unknown fault and propagated on a curved plane on the Palu-Koro and Matano faults. According to the Interferometric Synthetic Aperture Radar (InSAR) data, both principal (on-fault) and distributed (off-fault) faulting were identified and spatial displacement on the surface could be evaluated. To model the complex geometry of the coseismic rupture plane and corresponding deformation, we proposed a dynamic model through the Discrete Element Method (DEM). Our model demonstrated rupture along a planar fault at depth and several splay faulting with various deformations on the surface, corresponding to the observations. The simulations represented temporal rupture behavior that covers several earthquake cycles and the probability of superficial fault displacement, which shed light on subsequent seismic hazard assessment and probabilistic fault displacement hazard analysis, respectively.
Intertidal lagoons in the western Arabian Gulf are summer dead zones
Authors: Kaminski Michael , Prayudi Sinatrya Diko , Korin Asmaa , Tawabini Bassam S
Published: February 2023

Summer temperatures in excess of 60°C, have been measured in surficial substrates in the exposed areas of intertidal mudflats along the coast of the Arabian Gulf in Bahrain and Saudi Arabia. The incoming flood tide in coastal lagoons may have a temperature as high as 42°C. As a result, large swaths of the intertidal zone in the western Arabian Gulf are barren of living meiofauna (e.g., foraminifera, ostracods, gastropods, and worms) during the hottest months of the year. Samples collected from the intertidal zone in summer yield only dead assemblages of foraminiferal, ostracod, and gastropod shells. Dead assemblages of the foraminifer Peneroplis collected from the upper reaches of the intertidal zone consist largely of juvenile specimens, implying that the living populations, when present, do not reach maturity. In summer, the full range of living meiofaunal organisms is only observed in tidal channels that remain submerged during low tide.Our laboratory experiments have determined the upper temperature limit for the survival of gastropods and ostracods collected from coastal lagoons of the Western Arabian Gulf is in the range of 47 to 48.5 degrees C. At 50°C total mortality is observed. In Saudi Arabia, substrate temperatures exceeding the lethal temperature for these organisms are already observed in late April, and persist until late October.The presence of a summer dead zone for intertidal calcifying organisms is consistent with predictions of climate models, which suggested that by 2050 portions of the Arabian Gulf may become too hot to support animal life. On the western coast of the Arabian Gulf, these predictions have already become a fact. 
How do subduction zones spread over Atlantic-type oceans?
Authors: Duarte João C. , Riel Nicolas , Cadenas Patricia , Rosas Filipe M. , Welford J. Kim , Kaus Boris
Published: February 2023

There is a long-standing mystery regarding how subduction zones enter internal Atlantic-type oceans to complete their Wilson cycle. While the process of subduction initiation is challenging to tackle, the Atlantic is a natural laboratory that allows understanding of some of the different stages of the process of invasion of new subduction zones. Three different subduction zones seem to be entering the Atlantic from different edges: the Caribbean Arc, the Scotia Arc and around the Iberia Peninsula. While the first two examples constitute fully developed subduction zones, it is unknown how they will propagate in the future. Will they spread intra-oceanically or will the subduction migrate along the Atlantic passive margins? Iberia is a good place to investigate the processes involved in the formation of new subduction zones. There have been places of aborted subduction (along the Cantabrian margin), places of incipient subduction (North, West and Southwest Iberia) and there is a subduction arc currently propagating into the Atlantic Ocean (the Gibraltar Arc). We will focus on this last case. Last year, we presented a numerical model that showed that the Gibraltar Arc may indeed further propagate into the Atlantic. This year, we present new models that investigate the factors controlling such propagation. We test different parameters such as the presence of weak zones in the adjacent margins and in the oceanic lithosphere (fracture zones) to obtain insights into the main factors controlling the first stages of propagation of new subduction zones in Atlantic-type oceans. This work was funded by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES through national funds (PIDDAC) – UIDB/50019/2020- IDL
Dike-arrest vs dike-propagation and associated surface stresses: an example from the Younger Stampar eruption (13th century), Reykjanes Peninsula, SW Iceland
Authors: Corti Noemi , Bonali Fabio Luca , Russo Elena , Pasquarè Mariotto Federico , Gudmundsson Agust , Drymoni Kyriaki , Tibaldi Alessandro , Esposito Rosario , Cavallo Alessandro
Published: February 2023

Understanding the factors that affect dike propagation and dike arrest in the shallow crust, and subsequently control the associated dike-induced surface deformation is fundamental for volcanic hazard assessment. In this work, we focus on two dike segments associated with the Younger Stampar eruption (1210-1240 AD) on the Reykjanes Peninsula (SW Iceland). Both segments (spaced 30 m apart horizontally) were emplaced in the same heterogeneous crustal segment composed of lavas and tuffs. Here, the first dike to be emplaced fed a lava flow, while the second dike became arrested 5 m below the free surface without producing any brittle surface deformation. Therefore, this area represents an ideal case study to analyse the conditions that promote dike arrest or, alternatively, dike propagation to the surface. The outcrop also provides further examples of the absence of brittle deformation around a dike arrested just below the surface. For this work, we collected structural data from the dikes and the heterogeneous layers as well as from the nearby crater rows associated with the Stampar eruptions. We integrated our field observations with a high-resolution 3D model reconstructed from UAV-collected pictures through Structure-from-Motion photogrammetric techniques. These 3D model data were then used as inputs for Finite Element Method (FEM) numerical models through the COMSOL Multiphysics® software (v5.6). We performed a range of sensitivity tests to investigate the role of dike overpressure (Po= 2 - 4 MPa), the mechanical properties of the host rock (e.g., Young’s modulus), and the layering of the crustal segment subject to horizontal extension and compression boundary conditions.Our multidisciplinary structural analyses show that the Stampar crater rows is consistent in strike with the orientation of the volcanic system of the Reykjanes Peninsula, as well as the other historic and prehistoric eruptive fissures in the region. Furthermore, our numerical models indicate that the layering and the dissimilar mechanical properties of the host rock contributed to the arrest of non-feeder dike and the associated absence of brittle deformation at and above its tip. In particular, the layering (stiff lava flow on top of soft tuff) magnifies (concentrates) the compressive stress induced by the earlier feeder dike which cuts through an existing lower part of the surface lava flow. The horizontal compressive stress, in turn, is one reason for the very low overpressure of the non-feeder when it approached the tuff-lava contact, hence its arrest at the contact. Our studies can be applied to other dike-fed volcanic areas in Iceland and worldwide.
Improving efficiency of citizen science projects by targeted activation of selected stakeholder groups
Authors: Liang Christine , Schütze Claudia , Ködel Uta , Herrmann Thora , Schmidt Felix , Schütze Fabian , Schütze Sophia , Dietrich Peter
Published: February 2023

As citizen science is becoming a widely accepted research approach across multiple disciplines, it is essential to explore methods for effective recruitment, involvement, and retention of participants for these programs. An effective recruitment strategy results in motivated and engaged contributors, longer-term participation, and better communication exchange.In this research, we present two marketing approaches adapted from best practice in customer-facing fields in order to identify appropriate stakeholder groups for citizen science and keep motivation and retention of the participants high. Firstly, stakeholder analysis is a major tool within the frame of stakeholder management and includes the systematic identification of stakeholders and their relevance and influence on a project. Thus, efficiency of citizen science projects can be improved significantly by targeted identification and selection of participants and groups through stakeholder analysis, which are suited to generate the data needed to reach the project and research goals. Secondly, the value proposition canvas approach is based on business strategies to match products and services to the market or customer. The value proposition canvas can be adapted to scientific processes and the data generated can help citizen science groups to build a communication strategy that can clearly communicate the value of their message and shared goals to the participants.The application of stakeholder analysis and value proposition canvas is demonstrated using the case study of the project "Next Generation City Climate Services Using Advanced Weather Models and Emerging Data Sources" (CityCLIM, a European Union Horizon 2020 funded project), where the focus is to develop next-generation City Climate Services based on advanced weather forecast models enhanced with data from emerging data sources such as Citizen Science approaches for urban climate monitoring. Before meetings with citizens in pilot cities, stakeholder groups involved in the CityCLIM project were examined and their profiles were analysed using the value proposition canvas. Lessons learned from the use of these tools for engagement with citizens in pilot cities will be presented. Findings also provide an approach that can be used by citizen science groups in environmental observation to strategically target participants and tailor key communication messages, towards the goal of a focused and sustained monitoring of environmental processes.
A first insight into the hail distribution over Germany
Authors: Wilke Tabea , Schultze Markus , Lengfeld Katharina
Published: February 2023

Since major hail events are quite rare in Germany, there is a lack of information in hail occurrence, size and its spatio-temporal distribution. As hailstorms are often locally very limited events, the hail distribution is hard to analyze precisely. Hail reports can only give a first intuition about the amount of hail overall. There might be a bias in the amount of reports towards too many reports in highly populated areas, which could lead to an underrepresentation of reports in rural and sparsely populated areas. Areal information from weather radar networks can overcome this issue with a high spatio-temporal resolution. As an addition, data from the German Insurance Association (GDV) about damages through hail serve as a very certain source for hail occurrence.The German radar network consists of 17 dual-polarimetric radar systems, which cover Germany more or less completely. For the analysis of the hail distribution, the Maximum Expected Size of Hail (MESH) and a method based on Vertical Integrated Ice (VII) are used to estimate the hail size. Those sizes are reduced to thresholds to obtain where hail is reasonable or have a significant large size. The results of MESH and VII are finally compared to the eyewitness reports sent to the European Severe Weather Database and the WarnWetter-App. An important comparison are the loss data by the GDV. It can give further insides into the amount and the size of hail.