bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing UAS-based Earth Science Through Coordinated Facility Support
Authors: Crosby Christopher , Tyler Scott , Mattioli Glen , Harpold Adrian , Glennie Craig , Wartman Joe , Kratt Christopher
Published: March 2024

Uncrewed Aircraft Systems (UAS) represent an evolving and important set of tools for earth science and engineering. While low-cost uncrewed aircraft systems (UAS) can be acquired and operated by individual researchers for simple surveying or photography, very high-resolution observations using advanced sensors are often out of reach for most researchers. Over the past 5 years, U.S. National Science Foundation (NSF)-supported facilities have developed specialized UAS and UAS sensor capacity; however, this has largely been done independently and at very modest levels of support. Nevertheless, there has been growing success in supporting NSF and other federal researchers’ needs in the areas of topographic mapping, geothermal imaging, wildlife inventories, post-disaster monitoring and critical zone observations. To help make UAS resources more widely available, five NSF-supported Earth science facilities (NCALM, the GAGE Facility operated by the EarthScope Consortium, NHERI-RAPID, OpenTopography, and CTEMPs) have joined together to create the UAS Federation (UASFederation.org). Each of these facilities have supported UAS activities in the past, but they were generally small components of each facility, and often not well advertised or subscribed. Through formal coordination and a common portal, this new federation effort will enable Earth science researchers to access a much broader suite of sensors, aircraft, ​​FAIR data archiving resources, and expertise.The UAS Federation currently manages over 35 aircraft (6 heavy lift airframes, 7 medium lift, and at least 23 light duty airframes) along with remote-sensing systems that collect a broad range of data, including lidar; airborne magnetics; hyperspectral, multispectral, and thermal images, and albedo. Numerous cameras with RGB capacity are also available. In addition, we can provide access to software and over 140 archived UAS data sets. In the future, the UAS Federation will be developing and distributing training and instruction support. 
Sensitivity Analysis of Bioretention Cells for Stormwater Management: A Study in Secondary Cities of India
Authors: Tripathi Indra Mani , Mohapatra Pranab Kumar
Published: March 2024

The present study conducts a comprehensive sensitivity analysis of bioretention cells, a green stormwater management infrastructure, in the context of urban stormwater systems in secondary cities of India (Bhopal and Kozhikode). The research aims to enhance our understanding of the performance and effectiveness of bioretention cells in mitigating the impacts of urbanization on stormwater runoff. Utilizing the Storm Water Management Model (SWMM), the study employs a systematic approach to assess the sensitivity of bioretention cells to various design and environmental parameters. The initial screening of diverse design parameters is performed using the one-factor-at-a-time (OAT) sensitivity analysis method. Subsequently, pivotal parameters, namely, conductivity, berm height, vegetation volume, suction head, porosity, wilting point, and soil thickness, are identified for further sensitivity analysis. Around 500 randomly and uniformly distributed samples for each sensitive design parameter are simulated using a Python wrapper for the Storm Water Management Model (PySWMM). These simulations are conducted under varying design storm scenarios. This research contributes valuable insights into the optimal design and configuration of bioretention cells tailored to the specific challenges posed by stormwater in secondary cities of India. By systematically analyzing the sensitivity of these green infrastructure elements, the study aims to inform urban planners, engineers, and policymakers about effective stormwater management strategies.
Tectonic monitoring with low-cost multi-GNSS installations in Greece
Authors: Bedford Jonathan , Chousianitis Konstantinos , Ganas Athanassios , Mouslopoulou Vasiliki , Sokos Efthimios , Roumelioti Zafeiria , Nikolakopoulos Konstantinos , Pappas Christoforos , Ramatschi Markus , Falck Carsten , Männel Benjamin , Garcia Cristian , Peña Carlos , Cökerim Kaan , Latypova Elvira , Gianniou Michail , Ioannidi Paraskevi Io , Pikridas Chris , Lazos Ilias , Saltogianni Vasiliki
Published: March 2024

In 2023, we began installing a low-cost tectonic multi-GNSS network in Greece, funded by the European Research Council. We have installed a total of 45 permanent/continuous-mode stations, with another 15-20 to be installed in 2024. Installations so far have been mainly on the Peloponnese peninsula, with the strategy of increasing spatial resolution in between the existing research and privately operated GNSS networks. Station maintenance is funded by the project (ERC StG: TectoVision) until 2027, but it is the intention that as many as possible of these stations can stay installed (as permanent installations).The scientific purpose of the new stations is to increase spatial resolution of microplate motions in Greece but these data will also be of use to other research fields needing single- or multi-GNSS observables. Accordingly, these data are being released without embargo subject to completion of quality control checks (with the data publication and link to download to be finalized before EGU 2024).We consider this installation campaign to be a pilot project in affordable, rapid densification of tectonic-grade GNSS stations. Part of our strategy has been to use relatively low-cost monumentation for the geodetic marker onto which the low-cost installations are installed. Most stations are connected to mains electricity supplies of public buildings, with the monumentation being installed on flat roofs of these buildings. In higher altitude areas where flat roofs are rare, we have made 3 special installations at bedrock sites, with radio telemetry linking to a radio-receiving station in the nearby villages. We use a range of telemetry solutions, with the most common being the transfer of the 30s sampling data via a router containing a Machine-to-Machine (M2M) sim card.In this presentation, we will show data quality metrics from the initial analysis of 6-11 months of observations and compare to the time series that can be processed from more expensive receiver-antenna combinations. We will also discuss what the team has learned practically (on-site) and logistically about installing low-cost GNSS stations at scale.
Quantifying Evapotranspiration and Gross Primary Productivity Across Europe Using Radiative Transfer Process-Guided Machine Learning
Authors: Wang Sheng , Zhou Rui , Prikaziuk Egor , Guan Kaiyu , Gislum René , van der Tol Christiaan , Fensholt Rasmus , Butterbach-Bahl Klaus , Ibrom Andreas , Olesen Jørgen Eivind
Published: March 2024

Accurately quantifying water and carbon fluxes between terrestrial ecosystems and the atmosphere is highly valuable for understanding ecosystem biogeochemical processes for climate change mitigation and ecosystem management. Remote sensing can provide high spatial and temporal resolution reflectance data of terrestrial ecosystems to support quantifying evapotranspiration (ET) and gross primary productivity (GPP).  Conventional remote sensing-based ET and GPP algorithms are either based on empirical data-driven approaches or process-based models. Empirical data-driven approaches often have high accuracy for cases within the source data domain, but lack the links to a mechanistic understanding of ecosystem processes. Meanwhile, process-based models have high generalizability with incorporating physically based soil-vegetation radiative transfer processes, but usually have lower accuracy. To integrate the strengths of data-driven and process-based approaches, this study developed a radiative transfer process-guided machine learning approach (PGML) to quantify ET and GPP across Europe. Specifically, we used the Soil Canopy Observation, Photochemistry, and Energy fluxes (SCOPE, van der Tol et al. 2009) radiative transfer model to generate synthetic datasets and developed a pre-trained neural network model to quantify ET and GPP. Furthermore, we utilized field measurements from 63 eddy covariance tower sites from 2016 to 2020 across Europe to fine-tune the neural networks with incorporating physical laws into the cost function. Results show that PGML can significantly improve the SCOPE simulations of net radiation (R2 from 0.91 to 0.96), sensible heat fluxes (R2 from 0.43 to 0.77), ET (R2 from 0.61 to 0.78), and GPP (R2 from 0.72 to 0.78) compared to eddy covariance observations. This study highlights the potential of PGML to integrate machine learning and radiative transfer models to improve the accuracy of land surface flux estimates for terrestrial ecosystems.
Observation requirements for precise determination of local (quasi)geoid
Authors: Huang Jinshui , Zheng Guolei , Yushan Ailixiati , Qiu Bang
Published: March 2024

Many geodetic-related observations nowadays require a precise local geoid height that is as accurate as sub-centimeters. Here, we develop a method to combine global Earth Gravitational Model (EGM), Digital Terrain Model (DTM), as well as highly accurate local gravity and Global Navigation Satellite System (GNSS) observations to achieve this goal. We carried out several observation campaigns to obtain high space resolution and high accuracy gravity and GNSS data. Firstly, we analyze the accuracy of the commonly used methods such as those that use EGM only or use EGM and DTM combined. Then we test our method with a synthetic earth that was developed with EGM, DTM, and local high-resolution topography. Our results should that, the high degree EGM-only geoid has a mean error of tens of centimeters; the geoid from combined EGM and DTM can achieve accuracy of several centimeters; and if we want to have a local geoid with deviations less than sub-centimeter, high accurate observations with space resolution as high as 1"x1" are needed.
Self-accelerating rogue waves
Authors: Shugan Igor , Chen Yang-Yih
Published: March 2024

We present a theoretical study of bichromatic weakly non-collinear Airy-type waves propagating with various amplitudes in water of infinitedepth. The coupled nonlinear Schrödinger equations are invoked to study the behavior of self- and cross-interacting Airy wave packets. Wedemonstrate that bichromatic pulses possess the main properties of single Airy wave packets—shape invariance and self-acceleration or selfdeceleration—when propagating in a dispersive medium. Accounting for nonlinearity leads to a strong dependence of the structure, stability,and propagation velocity of wave pulses on their amplitude. We show that interacting pulses of Airy-type waves can form giant acceleratingand decelerating waves. The study of accelerating and decelerating bichromatic wave pulses of the Airy type significantly expands theset of scenarios for the occurrence of rogue waves in various physical media.
Abstract Title: Water uptake of Phreatophytes and Non-phreatophytes in the N-P CZO in Central India through Sapflow measurements
Authors: Bhilavekar Devlal , Patil Sachin , Mitkari Mayur , Amrit Kumar , Dhyani Shalini , Pujari Paras
Published: March 2024

 
 
The Narkhed-Pandhurna Critical Zone Observatory (CZO) is an agriculture intensive watershed in the central India. Agriculture accounts for approximately 39.92% of the total area (137sq.km) of the watershed. The watershed is the hub of orange cultivation in the country. The irrigation of the orange orchards is met by Flood irrigation. Besides, the study area is characterized by cultivation of wheat, gram, soybean, rice, red gram, cotton, and vegetables. In view of the indiscriminate withdrawal of groundwater, the groundwater stage development is on the verge of over exploitation. In this scenario, the water demand of the trees, namely Orange (Citrus sinensis) and Neem (Azadirachta indica) trees is being studied through measurement of the root water uptake in the month of October, November and December, 2023. The thermal dissipation probe sensors (SF-G) were used at real time data over 30 minute’s interval to track the daily changes in sap flow throughout the study.
The findings reveal notable distinctions in sap flow characteristics. On an average, the water uptake by Orange trees was 79.83, 88.94, and 80.02 Litres/month during the months of October, November, and December 2023, respectively. The water uptake is significantly less than the water used for irrigation (5500 litres/month).  In contrast, Neem trees exhibited lower water consumption with values of 11.65, 8.54, and 6.42 Litres/month during the same period. This indicates that Neem trees have a comparatively lower water uptake compared to Orange trees. The lower water uptake is on account of limited availability of soil moisture in view of absence of irrigation. The study can lead to informed understanding of plant water dynamics, thereby enhancing knowledge related to plant health and ecological systems, with practical implications for improved irrigation practices in semi arid regions.
 
Combined analysis on information of xenocrystic/inherited zircons within igneous rocks of Northern Xinjiang in northwestern China: imaging the deep crustal components through time
Authors: Zhang Jianjun , Wang Tao , Tong Ying , Huang He , Song Peng
Published: March 2024

Inherited/xenocrystic zircons entrained in magmas offer a unique opportunity to identify cryptic magmatic episodes in the deep crust and thus to image lithospheric thickening and crustal evolution. We investigated zircon xenocrysts within igneous rocks (mostly granitoids) from the Northern Xinjiang region in the southwestern part of the Central Asian Orogenic Belt (CAOB) to evaluate their potential as a probe of crust evolution, by using the previously ignored information of our newly obtained and compiled dataset of xenocrystic/inherited zircons (e.g., U-Pb age and Hf-O isotopic data). Different ancient age distributions of these zircons and the varying U-Pb ages and heterogeneous Hf isotopes demonstrate the ancient magmatic pulses in the crust of NW CAOB. Combined with the information from detrital zircons, and through the published plate motion models, we further compare these ancient age peaks in variable time-slices, e.g., from Proterozoic to Paleozoic, to interpret the recycling and transport of continental material. This innovative approach enhances our understanding of orogenic processes, shedding light on imaging the recycling and transport of deep continental materials.
Combination and analysis of the SLR monthly Earth’s oblateness variation solutions from different processing strategies
Authors: Yu Hongjuan , Zhang Lin , Zhang Yong
Published: March 2024

The publicly available SLR-derived monthly Earth’s oblateness C20 (or J2) time series exhibits varying levels of noise or systematic errors depending on the processing strategies used during estimation. We propose the use of two strategies, variance component estimate (VCE) and equal weighting (EW), to combine the SLR-derived J2 time series from four internationally renowned institutions. The resulting combined J2 time series is theoretically expected to demonstrate enhanced quality by reducing noise and systematic errors compared to individual contributions. These two combined solutions alongside four individual solutions are then discussed by analyzing their effects on global and local mass changes, thus exploring the potential for an optimized J2 time series in GRACE applications. The two combined SLR-derived J2 time series can assess the accuracy of the GRACE-derived J2 time series, which has shown poor but progressively improving accuracy. Results indicate that the RL06 version model of GRACE-derived J2 significantly outperforms the RL05 version, thus rendering the 160-day ocean tide effect in RL06 negligible. Moreover, significant discrepancies and lower quality among the various institutions' GRACE-derived J2 lead to Antarctic/Greenland ice sheet mass change estimates notably deviating from SLR-derived results. Therefore, upon replacing the GRACE-derived J2 time series with the VCE-combined SLR-J2 time series, the difference between the calculated mass change of the Antarctic/Greenland ice sheet and the RACMO2.3p2 model is theoretically the smallest, displaying the highest correlation coefficient between them.
Inferring Katabatic Jet Height with Near-Surface Measurements
Authors: Lord-May Cole , Radić Valentina , Stiperski Ivana
Published: March 2024

Understanding the development of katabatic wind systems above mountain glaciers is essential to better constrain the response of the local glacier microclimate and surface melting to large-scale climate forcing. The vertical turbulent flux profiles, and consequently turbulent fluxes at the glacier surface during katabatic flow, depend strongly on the height of the near-surface katabatic jet. However, direct measurements of jet heights are rare as they require balloon soundings or meteorological towers; neither of which are appropriate for long-term installation on glaciers. In this study, we conduct a multi-month field campaign in the summer of 2023 on the Kaskawulsh Glacier in the Yukon, Canada, measuring mean meteorological variables (up to 5m above the glacier surface), and turbulent fluxes at three heights (1m, 2m, and 3m above the surface) derived from eddy-covariance measurements. Over 30 hours of atmospheric  profiling with wind and temperature sensors tethered to a kite provides temporally and spatially high-resolution vertical profiles of katabatic flow. Using Multi-Resolution Flux Decomposition (MRD) applied to the eddy-covariance data from only one near-surface sonic anemometer, we introduce a method to infer the height of the katabatic wind speed maximum using the length scales of the most energetic eddies contributing to the heat flux. The inferred katabatic height for each 30-min interval of observations agrees with the corresponding measured 30-min average height from the atmospheric profiling, with a correlation of 0.73 and a mean bias error of 0.3m between the two datasets. We demonstrate that turbulent mixing lengths of momentum and heat fluxes can also be quantified with the use of MRD on the eddy-covariance data, and we propose a simple modification in the parametrizations of mixing-length models accounting for the near-surface katabatic jet. We corroborate these findings with data collected as part of the Second Meteor Crater Experiment (METCRAX II), providing tower-based measurements of deep katabatic flow at non-glacier terrain in the Arizona Meteor Crater.
Numerical modelling of continental margin of the Eurasian Plate Rifting and Tectonic evolution.Causes of the highest metamorphic temperature in the Hsuehshan Range and Backbone Range 
Authors: zheng ming-jun , Lee Yuan-Hsi , Tan eh
Published: March 2024

Many orogenic belts today preserve evidence of past crustal rifting. During the syn-rifting, the crust undergoes thinning, forming rift basins with thick sedimentary deposits. The upwelling of the mantle during this extensional phase increases the geothermal gradient within the basin, affecting the crust and sedimentary rocks.In this study, we used numerical models to simulate the temperature changes in sedimentary rocks within rift basins during both the active rifting phase and the passive continental margin phase after rifting cessation. We found that under a stretching rate of 0.7 cm per year, after 20 million years of continuous stretching, the geothermal gradient within the basin can reach 50-60°C per kilometer, with sedimentary rocks reaching temperatures as high as 450-500°C. After 20 million years of cooling following the end of stretching, the temperatures of the sedimentary rocks decrease by nearly 100°C, and the geothermal gradient reduces to approximately 30°C per kilometer.We believe that these phenomena can be correlated with the evolution of the Hsuehshan Range in Taiwan, which experienced a transition from rifting to a passive continental margin. During the rifting phase, the temperatures of the sedimentary rocks within the basin reached high metamorphic temperatures of 450-500°C, as indicated by carbonaceous material Raman spectroscopy (RSCM). As the region entered the passive continental margin phase, the rocks gradually cooled, with a temperature decrease of nearly 100°C prior to the onset of mountain building in Taiwan. Similar high-temperature metamorphic temperatures were obtained through RSCM analysis along the Central Cross-Island Highway and Northern Cross-Island Highway, exceeding the closure temperatures of zircon core tracks. However, some zircon core tracks in certain areas did not yield closure ages, suggesting that the high metamorphic temperatures obtained from RSCM analysis were inherited from previous stretching events rather than occurring during the Penglai orogeny.
Impacts of climate variability on rice yield and diseases in coastal Bangladesh: A systematic literature review with climate and crop data analysis
Authors: Mousumi Moriom Akter , Paparrizos Spyridon
Published: March 2024

Climate change has given a new dimension to the unpredictability of rice yields. Climate variability and change impact rice yield directly through the variation of climatic variables. Rice yield is also affected by pests and disease occurrences. However, climatic impacts on rice pests and diseases are not well known. This study aims to investigate the impact of climate variability on rice yield and diseases in coastal Bangladesh through systematic literature review (SLR), complemented by climate-crop data analysis. Mann-Kendall (MK) tests were conducted to assess the trends in climatic variables, while a mixed-effects model was employed to evaluate the influence of climatic variables on rice yield. Logit models were also used to identify the most critical weather parameters influencing the disease occurrences. SLR indicated that 61% of studies reported negative effect while 18% reported positive effect of climate variability on rice yield. Historical climate-crop data analysis indicates that both temperature (0.04°C/year) and humidity (0.14 %/year) have significantly increased. Despite a short-term positive effect of temperature and humidity on rice yield, a chronic cumulative negative effect was found over 38 years. Moreover, there was a positive correlation of rice yield with temperature and humidity. Additionally, trends of climatic variables had a negative effect (-10.9%) which is equivalent to a yield reduction of 140 kg/ha/year. Due to increased temperature and humidity, the occurrence of sheath blight disease was increasing higher than that of blast and bacterial blight disease. These findings are consistent with SLR. Sustainable rice production therefore needs better adaptation strategies at the farmers’ level.  It is suggested that the agricultural extension department should provide training to farmers regarding climatic parameter changes and their impact on rice diseases and yield, usage of climate information services, as well as climate-smart rice production, is imperative for better adaptation to climate change.
Hot spots and hot moments of N2O fluxes explained by monthly dynamics of soil microbiome in drained peatland forest
Authors: Espenberg Mikk , Ferch Zane , Kazmi Fahad Ali , Escuer-Gatius Jordi , Gadegaonkar Sharvari Sunil , Ranniku Reti , Maddison Martin , Soosaar Kaido , Pärn Jaan , Mander Ülo
Published: March 2024

The nitrogen (N) cycle involves intricate interactions affected by the spatial and temporal variability. Hot moments, occurring short-lived across seasons, significantly contribute to temporal nitrous (N2O) emission fluctuations. Likewise, N2O emissions exhibit localized spatial variability as hot spots. Year long monthly based studies of soil N cycle microbiome dynamics in peatland forests are unknown. This study investigates the relationship between soil microbial communities and N2O gaseous fluxes within a drained peatland forest throughout a year. Key research questions are: how are the genes responsible for N cycling in the peatland spatially and temporally distributed?; what patterns are there between soil characteristics (e.g., soil water content, soil temperature and pH) and N cycling gene abundances?Soil samples from 12 sites within a drained peatland forest in south-eastern Estonia were collected over a year and analysed for their physical and chemical properties and the abundance of genes associated with N cycling. Quantitative polymerase chain reaction was used to evaluate the bacterial and archaeal community abundances by quantifying the abundances of specific 16S rRNA genes and to evaluating the abundances of 10 genes associated with N cycling: denitrification (nirS, nirK, nosZ clade I, nosZ clade II, and fungal nirK), nitrification (bacterial, archaeal, and comammox amoA), DNRA (nrfA), and N fixation (nifH). This data was paired with N2O flux data collected in automatic dynamic gas chambers throughout the study period.Spatial variations apparent in the soil's chemical and physical composition reveal distinct vegetation and microbial communities across the area. Archaeal 16S rRNA, along with genes associated with N cycling (fungal nirK, nosZI, bacterial and comammox amoA), exhibited correlations with N2O emissions. Archaeal 16S rRNA, bacterial amoA, fungal nirK, and nosZI were positively correlated with N2O emissions. Throughout the year, water table levels and volumetric water content significantly influenced both N2O emissions and the abundance of N cycling genes. The site encompasses specific areas with consistently higher N2O emissions (hot spots) and periodic peaks in emissions (hot moments) due to the combined interplay of physical, chemical, and genetic attributes within the peatland soil.
Quantification Studies on Ephemeral Gully Erosion
Authors: Xu Ximeng
Published: March 2024

Ephemeral gullies (EGs) are major contributors to sediment loss and land degradation on cultivated lands. EG is an important linear erosion feature, often occurring at mid-slope position, that can be greatly influenced by upslope and lateral inflow. This study quantified the ephemeral gully erosion influenced by the upslope and lateral inflow, and the results showed that upslope and lateral inflow both contributed to the runoff connectivity of the EG channel and lateral rills in the EG system. For these simulated conditions, upslope inflow contributions to total runoff and soil loss were 62–78% and 65–81%, respectively, while lateral inflow only contributed around 10%. The contribution differences could be attributed to flow hydrodynamic characteristics in that shear stress and stream power in the EG channel were 4.9–8.6 times greater than those on the lateral slopes. From sheet flow to rill flow and EG channel flow, the flow regime gradually shifted from laminar and subcritical flow to turbulent and supercritical flow. The flow force, power, and energy correspondingly increased as the flow regime changed toward turbulent and supercritical. Both field monitoring and indoor simulation displayed the additional sediment delivery caused by upslope sediment-laden flow, verifying the transport-dominated sediment regime in EG systems. In field observations, the sediment increment coefficient (SIC, ratio of net sediment delivery caused by upslope sediment-laden flow to the total sediment delivery) on an event scale varied from 4.6% to 88.6%. In indoor simulations, the SIC changed from 24.9% to 87.5%. The SIC linearly decreased as the sediment concentration of upslope inflow increased. Field monitoring showed complicated phenomena because of natural random variations. SIC also generally decreased as the sediment concentration of upslope inflow increased. Laboratory simulations verified the field monitoring results of extreme rainfall events with large rainfall amounts and intensities. In future studies, multiple morphological criteria defining EG under various environments are urgently needed. Similar to the continuous sediment transport equations for rill erosion, continuous sediment transport equations for EG erosion need to be developed.
Pressure-Stimulated Rock Current as Loading Diorite to Failure: Experiments and Mechanisms
Authors: Mao Wenfei , Wu Lixin , Xu Youyou
Published: March 2024

The electric precursors of rock fracturing or rock failure are essential in understanding the rock physics and rock dynamics. In this study, by partly compressing cubic- and conical-shaped diorite specimens to failure, the pressure-stimulated rock current (PSRC) between the loaded volume and the unloaded end of each specimen was detected. A remarkable step-like increment in PSRC was uncovered when the uniaxially applied stress reached 83%–98% of the failure strength of dried specimens, and the drastic oscillations signals of PSRC appeared shortly prior to specimen failure. Then same detection experiments were carried out by using diorite specimens that were fully saturated with pure water, aiming to investigate the influence of water on the PSRC. Consequently, the sharper oscillations of PSRC signals were detected prior to saturated-rock failure, with which the magnitude of PSRC was several times larger than that of experiments with dried samples. Besides, such PSCR feature was also illustrated when the dry specimens were biaxially loaded. Therefore, both the water content and loading modes had obvious influences on the PSRC occurred shortly prior to impending rock failure.
By discriminating several physical mechanisms of rock current, it was found that the observed PSRC were attributed to a combination of several mechanisms. Therein, the outflow of positive holes was expected to play an important role. Based on the mineralogy and silicate chemistry, the peroxy links (-OO- structure), as the source of outflow of positive holes, are relatively abundant in the bridge oxygen. Thus, the diorite specimen had great ability to provide large amounts of positive holes since that the structure of feldspar minerals, as the major constitute of diorite specimen, is typical tectosilicates framework and thus all of oxygen atoms can be considered as bridge oxygen. In addition, the numerical simulations based on PFC3D illustrated that the fracturing of feldspar minerals was associated with the significant invariances in PSRC shortly prior to rock failure. In terms of the saturated specimens, both the electrification effect and outflow of positive holes were expected to be mainly responsible for the drastic oscillations of PSRC prior to rock failure.
The results of this study not only demonstrate the possible precursor identification of rock fracturing in laboratory, but also exhibit potential support for earthquake perception and prediction by investigating the changes of ground surface electric potential, the ground surface electrical field and the electromagnetic signals.
Subseasonal prediction of regional Antarctic sea ice by a deep learning model
Authors: Wang Yunhe , Yuan Xiaojun , Ren Yibin , Bushuk Mitchell , Shu Qi , Li Cuihua , Li Xiaofeng
Published: March 2024

Antarctic sea ice concentration (SIC) prediction at seasonal scale has been documented, but a gap remains at subseasonal scale (1-8 weeks) due to limited understanding of ice-related physical mechanisms. To overcome this limitation, we developed a deep learning model named SIPNet that can predict SIC without the need to account for complex physical processes. Compared to mainstream dynamical models like ECMWF, NCEP, and GFDL-SPEAR, as well as a relatively advanced statistical model like the linear Markov model, SIPNet outperforms them all, effectively filling the gap in subseasonal Antarctic SIC prediction capability. SIPNet results indicate that autumn SIC variability contributes the most to sea ice predictability, whereas spring contributes the least. In addition, the Weddell Sea displays the highest sea ice predictability, while predictability is low in the West Pacific. SIPNet can also capture the signal of ENSO and SAM on sea ice.
Towards AI-enhanced prediction of Mediterranean cyclones
Authors: Cavicchia Leone , Scoccimarro Enrico , Gualdi Silvio
Published: March 2024

Intense cyclones form frequently in the Mediterranean region, with the potential to cause damage to life and property when they hit highly populated coastal areas. Cyclone impacts are caused by the associated strong winds, flash flooding and storm surge. The social and economic impacts are not limited to the Mediterranean area, as cyclones forming in the region can affect Central Europe. While the skill of weather models to forecast such events has dramatically improved over the last decade, the seasonal predictability of Mediterranean cyclones lags behind due to the limitations on horizontal resolution in probabilistic forecasts requiring a large ensemble of simulationss. Improving the climate prediction at a seasonal scale of those extreme events would be of great benefit for society, enabling better disaster risk management and reducing the economic losses they cause. A better prediction of climate extremes would also directly benefit a number of economic sectors such as the insurance and re-insurance industry.
The ambition of the CYCLOPS project is to use Artificial Intelligence techniques to enhance the prediction skills of Mediterranean cyclones in a state-of-the-art Seasonal Prediction System. Here we present initial results making use of AI to link those extreme events to their large-scale driver. The training of different machine learning models is performed using ERA5 reanalysis data. The assessment of model skill is evaluated on the C3S operational seasonal forecast in hindcast mode. The performance of machine learning models of varying complexity (e.g. random forest, artificial neural networks) is evaluated.
Determining the deformation temperatures and paleostress conditions of the Sestola-Vidiciatico Unit in the Northern Apennines, an exhumed shallow subduction zone, using calcite deformation twins
Authors: Williams Stewart , French Melodie , Rubin Claire
Published: March 2024

Understanding the stress conditions of active subduction zones has been a longstanding hurdle with critical implications for natural disasters considering stress/strain orientations and magnitudes can control shallow earthquakes and tsunamigenesis. The Sestola-Vidiciatico Unit (SVU) in the Northern Apennines is an exhumed subduction channel with exposures of up to 9 km paleodepth, having reached up to 200°C. This unit experienced a relatively limited deformation history and serves as a rare analog to the shallowest portions of active subduction megathrusts. We use calcite twin data from shear veins along mineralized faults surrounding the exhumed subduction interface to reconstruct paleostress orientations through calcite twin stress inversion. Combining orientation data with calcite twin paleopiezometry and geothermometry, we are able to reconstruct the stress state of the SVU during peak subduction and subsequent exhumation.During subduction, the maximum principal stress axis was oriented at a low angle to the subduction interface and the minimum principal stress axis oriented at a high angle, indicating N/NE directed compression. As subduction ceased and exhumation initiated, stress orientations inverted with the maximum principal stress axis becoming oriented at a high angle to the subduction interface and the minimum principal stress axis oriented at a low angle, indicating N/NE directed extension driven by primarily the weight of overburden material. These findings are consistent with theoretical orientations for both of these tectonic regimes and agree with previous studies interpreting subduction zone stress orientations. Calcite twin paleopiezometry and geothermometry suggests the rotation of principal stresses coincides with higher differential stresses during early exhumation. Based on the interpreted differential stresses and the reconstructed paleostress orientations, we model different possible explanations including contrasting mechanical strength between the contractional and extensional faults or changes in pore fluid pressure conditions between the two different tectonic regimes.
3D Dynamic Rupture Modeling of the 6 February 2023, Kahramanmaraş, Turkey Mw 7.8 and 7.7 Earthquake Doublet Using Early Observations
Authors: Gabriel Alice-Agnes , Ulrich Thomas , Marchandon Mathilde , Biemiller James , Rekoske John
Published: March 2024

The 2023 Turkey earthquake sequence involved unexpected ruptures across numerous fault segments. We present 3D dynamic rupture simulations to illuminate the complex dynamics of the earthquake doublet. Our models are constrained by observations available within days of the sequence and deliver timely, mechanically consistent explanations of the unforeseen rupture paths, diverse rupture speeds, multiple slip episodes, heterogeneous fault offsets, locally strong shaking, and fault system interactions. Our simulations link both earthquakes, matching geodetic and seismic observations and reconciling regional seismotectonics, rupture dynamics, and ground motions of a fault system represented by 10 curved dipping segments and embedded in a heterogeneous stress field.The first, Mw 7.8 earthquake features delayed backward branching from a steeply branching splay fault, not requiring supershear speeds. The asymmetrical dynamics of the distinct, bilateral second Mw 7.7 earthquake are explained by heterogeneous fault strength, prestress orientation, fracture energy, and static stress changes from the previous earthquake. Our models explain the northward deviation of its eastern rupture and the minimal slip observed on the Sürgü fault. 3D dynamic rupture scenarios can elucidate unexpected observations shortly after major earthquakes, providing timely insights for data-driven analysis and hazard assessment toward a comprehensive, physically consistent understanding of the mechanics of multifault systems.Our models illustrate the predisposition of complex fault geometries, prevalent in tectonically complex immature fault systems, for cascading multi-fault and multi-event earthquake sequences. The unexpected doublet dynamics maybe explained by stress and strength heterogeneity, and include branching and delayed triggering in backward direction; triggered high-stress drop events, a single fault system with variable relative strength hosting rupture propagating at highly variable rupture speeds across different segments and in different directions.
A Novel Hyper-Resolution Water Table Depth Product for the Contiguous US
Authors: Ma Yueling , Condon Laura , Koch Julian , Bennett Andrew , Defnet Amy , Artavanis George , Melchior Peter , Maxwell Reed
Published: March 2024

Groundwater is our largest freshwater reservoir, playing a key role in supplying drinking water, guaranteeing food security, supporting biodiversity, and sustaining surface water bodies. While we have water table depth (WTD) observations at approximately one million wells over the contiguous US (CONUS), WTD data are sparse at the city or individual farm level, where local decisions are often made. To address the challenge, we introduce a novel WTD product for the CONUS, that consists of hyper-resolution (1 arcsec, ~30 m) long-term mean WTD estimates from a random forest model trained on available WTD observations. Uncertainty assessment is also provided. The input data to the random forest model include annual mean precipitation and temperature, elevation, distance to stream, soil texture, and other geology-related data. The model implicitly learns pumping from the WTD observations used for training, and thus the WTD product accounts for human interference with groundwater. Compared to coarser-resolution WTD data, it provides better estimates for groundwater storage and the proportions of very shallow and very deep aquifers over the CONUS. The 1-arcsec WTD product represents our most accurate estimate of accessible freshwater for the CONUS to date, useful for sustainable freshwater management, groundwater depletion studies, and hydrological modeling improvement. Since the CONUS covers many different hydrogeological settings, the random forest model trained for the CONUS may be transferrable to other regions with a similar setting and limited observations. We plan to extend the study globally, with the initial effort focused on transferring groundwater knowledge between the CONUS and Denmark.
Interstellar Dust Dynamics and the Large-Scale Structure of our Heliosphere
Authors: Horanyi Mihaly , Ayari Ethan , Juhasz Antal
Published: March 2024

The local interstellar medium contains plasma, magnetic fields, neutral atoms, cosmic rays, and dust which all influence the heliosphere through interconnected time-dependent and multi-scale processes. The Interstellar Dust Experiment (IDEX) instrument onboard NASA's IMAP mission, to be launched in early 2025, will measure the flux, size distribution, and composition of interstellar (ISD) and interplanetary (IDP) dust particles characterizing the inflowing solid matter from the local interstellar medium reaching the inner heliosphere. IDEX dust detection is based on impact ionization, where elemental and molecular ions are generated in a high-velocity dust impact and analyzed in a time-of-flight (TOF) setup. The size, composition, and the large-scale structure of the heliospheric magnetic fields strongly influence the propagation of the charged ISD particles, including the effects of the so-called heliospheric filtering that prevents small ISD particles from entering the heliosphere. We report on the status of our modeling results and predictions for the expected IDEX measurements.         
Brittle initiation of dissolution-precipitation creep in plagioclase-rich rocks: Insights from the Bergen arcs, Norway
Authors: Moore Jo , Piazolo Sandra , Beinlich Andreas , Austrheim Håkon , Putnis Andrew
Published: March 2024

The initiation of shear commonly occurs spatially associated with fluid-rock reactions along brittle precursors. In many cases the relative timing of fracturing, fluid infiltration, reaction, and recrystallisation is unclear, making it difficult to disentangle mechanisms of shear zone formation from subsequent deformation and recrystallisation. Here we present the transition from an anhydrous and relatively undeformed precursor rock into a highly deformed and hydrated plagioclase-rich rock. The studied outcrop remarkably preserves both (1) the interface between the anhydrous granulite-facies parent lithology and a statically hydrated amphibolite-facies rock, and (2) a transition from statically hydrated amphibolite to the sheared amphibolite-facies lithologies. Detailed study of plagioclase chemistry and microstructures across these two interfaces using Electron Backscatter Diffraction (EBSD) and wavelength dispersive spectrometry (WDS) allow us to assess the degree of coupling between deformation and fluid-rock reaction across the outcrop. Plagioclase behaves dominantly in a brittle manner at the hydration interface and so the initial weakening of the rock is attributed to grain size reduction caused by fracture damage at conditions of ca. 720°C and 10-14 kbar. Extensive fracturing induced grain size reduction locally increases permeability and allows for continuing plagioclase and secondary mineral growth during shear, as evidenced by a general increase in the amount of hydration reaction products across the shear zone interface. Due to the apparent coupling of deformation and reaction, and the plagioclase microstructures such as, an inherited but dispersed crystallographic preferred orientation (CPO), fine grain size (5-150 µm), and truncation of chemical zoning, we conclude that deformation is dominantly facilitated by dissolution-precipitation creep in the shear zone.
Evaluation of the microgrowth patterns of shells of long-lived bivalve, Mercenaria stimpsoni as a paleoenvironmental proxy
Authors: Miki Shiono , Shirai Kotaro
Published: March 2024

Mercenaria stimpsoni is a new paleoclimatic archive in the mid- to high-latitude western Pacific coastal area. This species is a cold-water bivalve with a long life span (>100 years old), and shell growth patterns and oxygen isotope ratios are useful tools as paleoenvironmental proxies. So far it is known that the shells of M. stimpsoni have distinct annual lines with microincrements between each annual line. However, the relationship between microgrowth patterns and marine environment is not understood. Fossil shells of this species are often found in interglacial marine sediments in Central Japan. Thus, understanding the relationship between microgrowth patterns and marine environment is key to reconstruct paleoclimate with high temporal resolution in this region.The purpose of this study was to evaluate the usefulness of the microgrowth patterns in this species as a paleoenvironmental proxy. Sample shells were collected from the coasts of Hokkaido and Iwate Prefecture, Japan. Shells were then cut into thick sections along the maximum growth axis. The surfaces of the thick sections were polished. Photographs were taken with a Keyence VHX2000 at 300x to 1000x magnification. Photomosaics were created with Adobe Photoshop CC. Then, the number of microincrements and microincrement widths were measured with ImageJ. Then, 120 to 150 μg of carbonate powder was collected from the outer outer layer along the growth direction and provided for oxygen isotope analysis. Finally, we compared microgrowth patterns with marine environmental data. Growth line observations confirmed that approximately 100 microgrowth lines were formed per year in the shells, and that the micorogrowth patterns might reflect mainly seawater temperatures and planktonic blooms. In the poster presentation, we will report the relationship between microgrowth patterns and marine environment. By clarifying the relationship between them, the temporal resolution of paleoclimate reconstruction using this species can be improved to less than the annual scale.