bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine learning based real-time microseismic monitoring and stimulated fracture characterization at the Utah FORGE Geothermal site
Authors: Shi Peidong , Schultz Ryan , Lanza Federica , Scarabello Luca , Ermert Laura , Wiemer Stefan
Published: March 2024

In April 2022, a three-stage hydraulic stimulation was performed in a deep granite heat reservoir of low permeability at the Utah Frontier Observatory for Research in Geothermal Energy (FORGE). During the stimulation, around 1600 m3 pressurized fluids were injected into the target reservoir of ~2.4 km depth aiming at creating fracture networks and improving reservoir permeability for heat extraction. Microseismic monitoring is required to assess the stimulation efficiency and manage the induced earthquake risk during the stimulation. We perform near-real-time microseismic monitoring in a playback mode at the third stage of the stimulation where three deep monitoring boreholes equipped with three-component geophone chains were in operation. We apply machine learning (ML) techniques in combination with waveform back projection approaches to automate the microseismic event detection, increase microseismic event location accuracy, and promote the real-time capability of the monitoring workflow. Due to a lack of labeled datasets for model training or transfer learning, we devise a rescaling technique to tune the continuous microseismic recordings of high sampling rates that enables the application of existing ML models pre-trained on tectonic earthquakes. Our benchmark tests show that the proposed rescaling approach achieves high precision and accuracy in detecting microseismic events and picking their phase arrivals.With the proposed workflow, we compiled a high-resolution microseismic catalog containing around 36, 000 microseismic events with magnitudes of –3.0 to 0.5. Detected events are relocated using a double-difference relocation method and waveform cross-correlation-based arrivaltime refinement. We cluster the detected microseismic events according to their spatial distributions and identify the dominant stimulated fracture planes with principle component analysis of the different event clusters. The spatial distribution of the detected events nicely depicts the stimulated fracture networks which can be used to design the trajectory of the future production well. We analyze the spatio-temporal evolution of the induced microseismic events during and after the stimulation to illuminate the rupturing mechanisms responsible for the induced fracture networks. Induced microseismic events are analyzed together with the injection data to quantify the induced earthquake hazard and the hydraulic stimulation efficiency. The proposed microseismic monitoring workflow and the corresponding analysis provide more insights into the fracturing dynamics and the potential induced earthquake hazard in the Utah FORGE geothermal site, and would benefit the operation of other enhanced geothermal systems.
How to make climate communication more accessible to more  communities? Results from a case study featuring KNMI
Authors: Johannes Björk
Published: March 2024

Imagine that you  a (semi-governmental) scientific institute, conducting important and state-of-the-art research that you want to share with society. In addition to the science enthusiast that follows your every move and reads the news outlets that regularly cover your stories, you want to include groups of people that do not automatically come in contact with your communication efforts. How do you improve the accessibility of your science communication, specifically towards groups of people that are not automatically included? I will share valuable insights from my empirical social study on climate communication accessibility at the KNMI, the Dutch research and information center for meteorology, climate, air quality, and seismology.In my presentation at EGU 2024, I will describe several factors that play a role on the perceived accessibility of climate change communication. These insights are based on interviews and focus groups held with respondents living in low socio-economic status neighborhoods and rural areas. In addition,  focus groups and interviews with KNMI-employees involved in climate communication took place.[J(8] blog-like articles written by KNMI-employees were presented to respondents to read and evaluate. These articles aim to create understanding and awareness of climate phenomena and concepts and have been a vital part of KNMI's communication efforts for 10 years. I have analyzed this data through the lens of a conceptual model containing theories on accessibility and equity, models of communication, and framing and narratives.My research confirms well-known factors which influence accessibility to broader audiences. For example, the excessive use of scientific jargon has a negative impact on the understanding and accessibility of communication. In addition, my research probes deeper to identify aspects that explain why these well-known factors cannot easily be overcome and to uncover which other, less obvious factors, play a role. Aspects like cultural identity, social acceptance and peer pressure, literacies and capital, recognition, and equity all play a part in the machine of social inclusion and accessibility of climate communication. Challenges and opportunities arise both within the institution and in relation to the social groups included in this research.Based on the results and conclusions of this study, I will provide recommendations on how to improve the accessibility of climate communication to communities  that are typically reached to a lesser extent. While they are based on communication practices of the KNMI, they are generally applicable to other scientific institutions and/or governmental institutions. On the EGU 2024, I will present my recommendations to improve climate communication accessibility, as well as the results that these recommendations are based on.
Locked Frontal and Lateral Ramps on the Main Himalayan Thrust beneath NW Himalaya illuminated by precisely located seismicity
Authors: Shamim Sk , Ghosh Ayon , Mitra Supriyo , Priestley Keith , Sharma Swati , Wanchoo Sunil Kumar
Published: March 2024

The Kashmir ‘seismic gap’ in NW Himalaya, between the 1905 Kangra and 2005 Muzaffarabad earthquake rupture zones, has been replete with moderate-to-small earthquakes. GPS geodetic measurements across the Himalayan-arc reveal arc-normal convergence of ~11 mm/yr, which reduces towards the foreland in the India-fixed reference frame. In 2013 the Jammu And Kashmir Seismological NETwork (JAKSNET), and later the Himachal Pradesh Seismological NETwork (HiPSNET) was established to study the seismological characteristics of this ‘seismic gap’. Using continuous waveform data from these networks an earthquake catalog has been created using the Regressive ESTimator (REST) algorithm. Following this, seismic phases were manually picked from ~1100 earthquake records to determine the accurate arrival-times. A subset of these events based on the quality of picked phases are relocated using a probabilistic Non-Linear Location (NLL) method. These earthquakes have magnitudes between 0.5 and 4.5, and are distributed throughout the crust, with the majority concentrating at shallow (
Quaternary denudation rates in a tropical volcanic island: example of Santo Antao in Cabo Verde
Authors: Pik Raphael , Charreau Julien , Blard Pierre-Henri , Nomade Sébastien , Scao Vincent , Parmentier Amélie
Published: March 2024

The Earth surface, where life develops and stands, is strongly affected by denudation which is the sum of physical erosion and chemical weathering. Denudation impacts soil formation and agriculture, affects the relief stability and, at the geological time scale, controls the atmospheric CO2 via the weathering of silicates and the production of sediments that later bury organic matter in the oceans. In the context of global warming, it is particularly important to predict how denudation will change and hence impact the Earth Surface where we live. This requires to understand the links between past climate variability and denudation changes, especially during the Quaternary when Earth experienced rapid climate oscillations of amplitude similar to what is expected in the future due to anthropic impact. To reach this goal, quantitative estimate of past denudation rates during the Quaternary are needed especially in Volcanic island located in tropics because here silicate weathering and hence CO2 consumption is particularly efficient.In this study, we reconstruct Quaternary paleo-denudation rates in Santoa Antao, one of the largest islands of the Cabo Verde archipelago that is located in the Atlantic ocean 800 km off the coast of Senegal. To reconstruct the paleo-denudation rates we measured in situ cosmogenic 3He concentrations in ancient fluvial sediments stored in deep entrenched valleys across the island. The depositional ages of sediments were determined by dating using Ar/Ar adjacent volcanic layers (pumices or basalt lavas). For comparison between all data, paleo-denudation rates are normalized to modern 3He derived denudation rates across the same drainage basin obtained from the analysis of modern river sand in a previous study. This yields to a 0-550ka record of paleo-denudation rates that is compared to climate variations to discuss the potential links between the two.
Arctic spring and the onset of sea-ice melt: Early impressions from the ARTofMELT expedition
Authors: Tjernström Michael , Zieger Paul , Murto Sonja ,   ARTofMELT Science Team
Published: March 2024

The spring season in the Arctic Ocean has gained relatively little attention with detailed observations from expeditions, due to difficulties to navigate in the ice at this time of the year. This paper reviews experiences from the ARTofMELT (Atmospheric rivers and the onset of sea-ice melt) expedition in spring of 2023.ARTofMELT had two objectives: To study processes leading up to the onset of the sea-ice melt and to explore links to so-called atmospheric rivers (ARs). ARs are spatially and temporally distinct inflows of warm and moist air from farther south. To fulfill these goals, we instrumented the Swedish research icebreaker Oden and planned to locate her in the Atlantic sector of the Arctic Ocean north of Svalbard from early May to mid-June. Oden was equipped with advanced meteorological instrumentation including standard meteorology and 6-horly radiosoundings, radar and lidars for cloud and wind measurements, and a surface flux tower with eddy-covariance. An advanced suite of atmospheric chemistry and aerosol observations were also deployed along with water isotope measurements, and also sampled and profiled the upper ocean structure. To identify upcoming ARs, we used ensemble forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) at lead time up to seven days, to allow time to navigate the icebreaker to optimal positions and establish ice camps. While carrying out most of the observations on board, in-situ observations on the ice provide valuable details on the impact of ARs on the ice. On ice camps we therefore deployed a surface energy budget station and an ROV surveying the ice from below and also flew a tethered balloon HELIKITE system from the aft of the ship. Additionally, we also used the helicopter to deploy scientists on the ice (sampling snow, ice and water) and deploying buoys, and for flying the HELIPOD instrument package.ARTofMELT left Svalbard on 8 May and returned on 15 June. Starting with quite cold later winter conditions there was a brief warming period around mid-May, with an AR that brought air temperatures above the melting point twice (19 and 20 May). This was interrupted by a major storm, followed by a cooler period. From the end of May the surface started to gain heat, culminating in the onset of the melt at a second AR on 10 June. Both ARs were documented from ice stations.A major uncertainty was the navigation in the ice during late winter and this also tuned out to be the most difficult part of the deployment. The ice was thick and hard to break, the size of the largest ice floes was much larger than expected and short-term variations of the ice pressure made navigation very difficult. The maximum latitude obtained was ~80.5 °N, hence, we stayed in the Fram Strait ice pack. Also, only two brief ARs were encountered, less than expected. In spite of this we were able to gain a large amount of unique observations, both from the icebreaker when in transit and from two ice camps.
Evaluation of archaeological and pleistocene magnetic field models and their common features
Authors: Wardinski Ingo , Terra-Nova Filipe
Published: March 2024

Archeo- and paleomagnetic field models show a wide range of temporal variability and of spatial content. While the temporal variability may reflect true geomagnetic field variation, the different spatial content of individual models could be explained by different modeling strategies and data sources, but most likely by data uncertainties. To overcome these problems, we derive a time-dependent mean, median and robust Huber models over the last 100 kyrs from a large suite of different archeo- and paleomagnetic field models (AFM-M, AFM-Md and AFM-H, respectively). These models allow to identify common features of the past field  and to qualitatively assess the robustness and the significance of these spatial features throughout time.We evaluate each model over the entire period and compute structural criteria that quantify axial dipole dominance, equatorial symmetry, zonality and radial flux concentration at the CMB. These criteria are used to quantify the Earth-likeness of numerical dynamo simulations. Over 100 kyrs, the criteria show larger fluctuations than previously assumed, which implicates a wider range of numerical dynamo simulations to be considered as Earth-like.
Global convergence of incomes in a climate-constrained world
Authors: Oswald Yannick
Published: March 2024

Sustainable development aims for equal living standards in the Global North and Global South while limiting global warming as much as possible. If measured in monetary terms, it is well known that eradicating extreme poverty (so lifting people beyond $PPP 2.15 consumption expenditure per capita (pc) per day) does not threaten climate goals. However, just beyond extreme poverty is not an acceptable goal for the living standards of people. In Europe, for instance, people live between $PPP 30pc and $PPP 70pc on average depending on the country. Moreover, some research has shown that lifting all people globally to only $PPP 5.5pc per day already implies allocating a much bigger carbon budget share for poverty eradication given current techno-economic parameters. Hence, if global poverty is to be reduced substantially, high-income nations and groups require a more rapid reduction of emissions so that global climate goals remain met. Therefore, in this research, I explore global convergence scenarios of incomes, taking between-country inequality and within-country inequality into account. I do so based on data from the World Inequality Lab and consider the following constraints and parameters: (i) income level towards which countries and groups converge (e.g. $PPP 30pc consumption expenditure a day or $PPP 50pc and so forth) (ii) carbon budgets, (iii) time horizon (for example whether convergence happens until 2050, 2075 or 2100 and so forth) and (iv) technology evolution (the pace of carbon intensity reduction). By studying the trade-offs between these, I elaborate on possible growth pathways for low-income countries and low-income groups world-wide, and corresponding degrowth or steady-state pathways in Global North countries and high-income groups world-wide. I find, for example, that, if all high-income nations continue historic growth trajectories while low- and middle-income countries converge to an acceptably high level of income, strict carbon budgets are difficult to maintain and hence high-income countries might consider steady-state or degrowth trajectories to free up “growth space” in low-income countries. The results may inform country-specific and income-group specific climate-economic scenarios in integrated assessment models and the wider policy debate.   
Natural disturbances and protective forests: the effects of cascading and compound hazards after the storm VAIA  (Northeastern Italy)
Authors: Lingua Emanuele , Richter Paul , Faes Lorenzo , Berger Frédéric , Garbarino Matteo , Marzano Raffaella
Published: March 2024

Climate change is undeniably responsible for the increase in climate-related disturbances affecting Alpine communities. These phenomena are often the result of compound events, a combination of multiple climate-related hazards that contribute to socio-ecological risks. Among the key drivers of the increased vulnerability of Alpine communities are changes in forest cover, structure and species composition. Forests provide essential ecosystem services that support human well-being and play a crucial role in the mitigation of climate change. However, their health and stability are also particularly affected by large and high-severity climate-related disturbances. Therefore, in the framework of MOSAIC, an Alpine Space Interreg project funded by the European Union, a focus is being devoted to hazard-resilient and sustainable protective forest management, which is essential for managing climate-related hazards.  In order to support Alpine climate action plans, the project partners aim to collect, harmonise and share data on Alpine climate-related disturbances and hazards, as well as forecasting their future trends. MOSAIC strives to raise awareness among foresters, risk managers, decision makers and the public through an Alpine network of forest living labs. Here, some case studies and examples of disturbance interactions and their effects on protective forest stands are presented and discussed, with a special focus on the aftermath of VAIA, a windstorm that affected Northeastern Italy in 2018.
Transdisciplinary assessment of social-ecological vulnerability to Climate Change in Southwest Madagascar
Authors: Razanatsoa Estelle , Gillson Lindsey , Virah-Sawmy Malika
Published: March 2024

Climate models have shown that there will be an increasing susceptibility to drought in the future for semi-arid regions. However, the impact of these droughts depends on the sensitivity of landscapes and the adaptive capacity of communities. Using a vulnerability framework, and a mixed-methods approach, this paper assesses the vulnerability of the social-ecological systems along a rainfall gradient transect in southwest (SW) Madagascar at multiple timescales. We used a transdisciplinary approach, that combines synthesized regional climate records to assess the exposure to drought, and fossil pollen data from four sites ranging from wetter to drier areas to assess the sensitivity of landscapes over the last 2000 years. Local ecological knowledge (LEK) from household surveys from the driest sites in the Plateau Mahafaly was then conducted to infer adaptive capacity of local communities. Results show that over time, changes in climate linked to drought increase the vulnerability of the social ecological systems in Southwestern Madagascar particularly to the communities’ livelihoods in the driest regions, where there were fewer adaptation options, their need to migrate, and also on biodiversity. Although some coping and adaptation strategies including migration are in place for the communities, these might create feedback loop leading to further degradation and impacts on biodiversity and its conservation, especially in the driest regions where degradation is most likely to occur due to lower adaptive capacity. 
Tectono-metamorphic interaction between the upper mantle and lower crust during continental rifting in the western Betic Cordillera
Authors: Hidas Károly , Díaz-Alvarado Juan , González-Menéndez Luis , Azor Antonio , Pedrera Antonio
Published: March 2024

Recent geological mapping in the Ronda peridotites (Betic Cordillera, S Spain) has unveiled a consistent field correlation between lower crustal metamorphic units and specific tectono-metamorphic domains of the ultramafic massif. Mylonitic and highly tectonized spinel ±garnet peridotites (i.e., Grt-Spl mylonite and Spl tectonite domains) –that are considered to originate from a thick continental lithosphere– are in contact with garnet-bearing gneisses (i.e., kinzigites of the Jubrique unit) along a narrow but continuous mylonitic shear zone. Phase equilibrium calculations indicate that these metamorphic rocks align with an initial continental setting characterized by normal crustal thicknesses, which underwent two melting events. The first melting occurred at the base of the lower crust, while the second one took place at shallower crustal conditions and led to a more restricted melt production. By contrast, the spinel ±plagioclase peridotites (i.e., Pl-tectonite domain) –that are stable only at shallowest mantle levels within a highly extended continental lithosphere– are consistently found exposed in contact with heterogeneous granites and migmatites that form part of the Guadaiza crustal unit. According to new thermodynamic modeling, this migmatitic series record a single melting event characterized by a moderate melt production at the base of an extremely thin continental crust. The systematic correlation observed between the crustal metamorphic units and specific ultramafic domains of the Ronda peridotites –consistently overlaying the mantle rocks– indicates that their juxtaposition primarily resulted from the severe extension of the continental lithosphere.Previous and new U-Pb radiometric dating of zircons from gneisses, migmatites, and heterogeneous granites show that extensional processes, crustal anatexis, and melt stagnation occurred at around 280 Ma. Considering the structural position and correlation between mantle and crustal rocks, these radiometric ages suggest that a Permian high-temperature / low- to medium-pressure event uniformly affected the crustal units over the Ronda peridotites. This event coincided with the formation of characteristic ultramafic mineral assemblages in the Ronda massif, providing evidence for the interaction between upper mantle rocks and lower- to mid-crustal metamorphic rocks during that period.This research received funding from the Agencia Estatal de Investigación of the Ministerio de Ciencia e Innovación (AEI, MICINN, Spain) under the grant no. PID2020-119651RB-I00/AEI/10.13039/501100011033.
Spatio-temporal analysis of the ice mass changes over Greenland from GRACE and GRACE-FO.
Authors: Cambier Florent , Darrozes José , Llubes Muriel , Seoane Lucia , Ramillien Guillaume
Published: March 2024

Prediction of the trends of ice mass loss in Greenland can help for understanding what occurred during the last 20 years and in the future. The Level-2 GRACE and GRACE-FO solutions provided by the official computing centres CSR and ITSG as well as the combined products of the COST-G project give access to the spatio-temporal variations of the ice mass balance of Greenland from 2002 to present. We first reduce the GRACE data from post-glacial rebound. We propose to analyse these solutions by applying Singular Value Decomposition (SVD) and Empirical Mode Decomposition (EMD) to extract the trend. This trend is then removed from the timeseries for the Fast Fourier Transform (FFT) and 1-D Continuous Wavelet Transform (CWT) analysis. CWT and FFT analysis enable to unravel the long-term trend of the ice loss ranging from 6-9 years, as well as the annual and semi-annual part. The period of 6 to 9 years shows some correlation with meteorological and climate indexes such as North Atlantic Oscillation (NAO). The spatial component of the first SVD mode indicates that the ice melting is the most important along the west and southeast coast at the rate of -30 to -40 Gt/yr. Globally, the trend is not linear, it consist of different phases of acceleration and deceleration with rates between -60 and -340 Gt/yr.
Relative Paleo Intensity  and cyclostratigraphy as a tools to correlate the Hominin Sites Paleolakes Drilling Project Baringo core and Afar cores.
Authors: Sier Mark , Hilgen Frits , Lourens Luc , Castillo Guerra Joanne , Verkooijen Stephie , Team HSPDP Science
Published: March 2024

The Hominin Sites Paleolakes Drilling Project (HSPDP) is a multidisciplinary initiative that aims to understand how landscape and climate change shape human evolution in East Africa over the past 3.4 Ma. For this purpose, HSPDP has drilled long sediment cores in Kenya and Ethiopia: West Turkana, Magadi, Chew Bahir, Baringo, and Northern Awash localities. The drilled cores enabled to produce multiple high resolution environmental and climate proxy records, which can be correlated to nearby sites that are important for human evolution.
The focus of this presentation are the Baringo and Northern Awash HSPDP cores with an age range for both cores from around 2.4 Ma till 3.4 Ma. This period covers the earliest stages of Homo evolution, diversification of Paranthropus and the occurrence of the earliest technological manifestations of hominins. This time range also covers the period prior to the Northern Hemisphere glaciations, the onset of glaciation, and the intensifications of the glaciation.
An important starting point for proper correlation between environmental and climate proxy records with important stages in human evolution is a high-resolution age model. For the Baringo core, a high resolution age model has been published based on tephrostratigraphy and magnetostratigraphy. In this presentation, we will show new preliminary relative paleo intensity data (RPI) and cyclostratigraphy data. RPI is a tool that uses the fluctuation in intensity of the Earth's magnetic field to chronologically constrain a sedimentary sequence at high resolution. Cyclostratigraphy is based on the principle that periodic changes in insolation caused by the variation of the Earth's precession, obliquity, and orbital eccentricity cycles are strong drivers of climate change and these can be recorded in sediments.
These methods have the potential to improve the age model of the Baringo core. Furthermore, for the Afar cores no age model has been developed so far due to lack of tephra’s and problems with magnetostratigraphy. In this presentation we would like to present the age model current situation and show the how methods mentioned above could help build an age model for the Afar cores.
The role of pyrite surface area and thermochemical sulfate reduction in clastic-dominant Zn Deposits. 
Authors: Berger Peter , Magnall Joseph , Kühn Michael , Gleeson Sarah
Published: March 2024

It is vital to keep up with the demand for critical minerals during the transition to sustainable energy systems. Doing so requires expanding our knowledge of ore depositional processes. Pyrite is a common gangue mineral in clastic dominated (CD) deposits, which are the highest value Zn deposits. In CD-type deposits, pyrite is often part of the pre-, syn-, and post-ore paragenesis and can therefore provide an important redox buffer and potentially a source of sulfur during ore deposition. The distribution of syn-ore pyrite beyond economic mineralization can also form an important mineralogical halo around CD-type deposits.In this study we investigate the role of fluid interaction with different types of pyrite on ore formation in the Teena deposit (Australia). The host unit for the Teena deposit is an organic rich, variably pyritic, dolomitic siltstone. We created a series of 2D, reactive transport models using the software X2t (Geochemists Workbench) to investigate the role of pyrite surface area as a major control on ore deposition.Similar to many CD-type deposits, the main type of pre-ore diagenetic pyrite in the host unit is framboidal, which has a high surface area, whereas syn-ore generations of pyrite tend to be coarser grained. In the models, pyrite surface area was varied from 100 (syn-ore) to 10,000 cm2/g (diagenetic). Organic matter provided a drive for thermochemical sulfate reduction (TSR) in the models, and TSR rates were varied over several orders of magnitude in accordance with laboratory measured values.As the incoming hydrothermal fluid reacted with the host unit, pyrite and dolomite are dissolved and sphalerite is precipitated. The surface area of pyrite evolved as it dissolved and reprecipitated in the form of a more massive, lower surface area, hydrothermal pyrite.Models using the higher surface area values for diagenetic pyrite resulted in more compact and higher grade ore deposition. The pyrite at the inlet in this scenario dissolved completely. As the pyrite reprecipitated, it formed more extensive halo ahead of the sphalerite reaction front than in models using the lower hydrothermal surface area. Slower rates of TSR also broadened the pyrite halo and decreased the sphalerite ore grade. Low pyrite surface area coupled with low TSR rates resulted in a disseminated deposit. Based on these results, the paragenetic evolution of pyrite over the course of hydrothermal alteration and the resulting changes in surface area are an important control on ore grade and the extent of halo formation.
Satellite derived Intensity- Duration (ID) thresholds for landslide forecast in Idukki, India
Authors: Sekar Anamika , Siva Subramanian Srikrishnan
Published: March 2024

The Idukki district of Kerala experienced its worst disaster since 1924 in 2018 due to the excessive rain during the monsoon season from June to August. There were devastating landslides throughout the district accounting for the highest among the state which included debris flow, soil slides and rockfalls,  ever since making the area more susceptible to landslides. Thus, forging the impending need of an early warning system is crucial. Here, the study attempts to create a rainfall threshold to predict landslides through a satellite based precipitation product - GPM (Global Precipitation Mission Integrated Multi-satellitE Retrievals). The global coverage and the improved resolution of the data makes it more effective in mitigating landslide disaster risk.  Hourly precipitation data was obtained from GPM for the 23 grids within the district where there was an occurrence of debris flow. As the largest number of landslides happened during a second spell of intense rainfall that lasted from July 11 to August 19, 2018, the rainfall during this time was analyzed. A total of 4 days in these two months were identified with high amounts of rainfall with August 15th showing continuous rainfall for 24 hours. Using the rainfall and the landslide data for 2018 the overall regional threshold over the district was estimated to be I= 5.42D-0.16, where I is the rainfall intensity in mm/hr and D is the event duration. A more precise threshold could be obtained by considering grid-wise rainfall thresholds in a more detailed analysis. 
The growing groundwater crisis in Iran and its impact on land subsidence: A nationwide survey using satellite InSAR
Authors: Haghshenas Haghighi Mahmud , Motagh Mahdi
Published: March 2024

In recent decades, the increasing water demand in Iran has led to extensive groundwater pumping, which has caused significant depletion of many aquifers across the country. This unsustainable extraction has resulted in the loss of groundwater resources and significant land subsidence, adversely affecting several agricultural and urban areas. While previous studies have identified the problem at local scales in major agricultural centers and metropolitan areas, the extent of land subsidence and its impact on groundwater resources, population, and infrastructure across the country is still unknown. This study aims to fill this gap by extending the monitoring and providing a comprehensive understanding of the issue through a nationwide survey that employs Interferometric Synthetic Aperture Radar (InSAR). We generate a large stack of small baseline interferograms at a spatial resolution of 100 meters. Assuming land subsidence is spatially localized and temporally correlated, we remove other signals, mainly from atmospheric phase delay, to isolate the subsidence. Our analysis of Sentinel-1 data from 2014 to the present has enabled us to map the subsidence rates across the country. Our findings indicate that over 50,000 sq. km of the country's land is experiencing significant land subsidence, primarily in agricultural areas, but also in urban areas. As this subsidence is associated with pumping from confined aquifers, we estimate an annual groundwater loss of almost 2 Billion Cubic Meters in Iran, which is in agreement with independent in-situ measurements and GRACE data. By combining our estimated groundwater loss with a land cover map and official agricultural production data, we explore how inefficient irrigation in certain parts of the country is the main driver of groundwater loss. Our study underscores the urgent need for immediate measures to address the issue of groundwater loss in Iran and mitigate its effects on the country's population and infrastructure.
The implication of Grenville orogeny on REE mineralization in migmatites and gneisses of Son Valley Crystallines Sonbhadra, Uttar Pradesh, North India
Authors: Verma Abhishek , Chinnasamy Sakthi Saravanan
Published: March 2024

The Son Valley Crystallines (SVC) of the Precambrian Chhotanagpur granite-gneiss complex (CGGC) of the Sonbhadra district Uttar Pradesh contain gneisses and migmatites which are highly deformed and metamorphosed. The study area encompasses different parts of SVC which are Arangapani, Kudri, Anjangira, Jarha, Nawatola, and Naktu. Here we found gneiss and migmatite except Nawatola and Naktu where we found felsic breccia. The foliation in migmatite is E-W but at places it changes to ENE-WSW. The leucosome part of the migmatite occasionally shows pinching and swelling and ptygmatic folding structures. Petrography of the leucosome of this gneiss and migmatite shows the dominance of microcline, orthoclase, quartz, and rare plagioclase with a minor amount of biotite and amphibole whereas the melanosome is dominated by biotite, rarely with amphibole and minor quartz and, feldspars. These rocks contain a higher amount of REE-bearing phases viz. zircon, garnet, apatite, titanite, monazite, and xenotime. The REE-bearing phases particularly zircon, monazite, and xenotime are found as inclusions mostly within biotite and occasionally in feldspars whereas apatite and titanite were found as inclusions exclusively within feldspars. Few zircon and monazite are found in intergranular space between different mineral grains. REE-bearing phases were analyzed in EPMA for total rare earth oxide (TREO) quantification and it was observed that TREO is 0.84 - 1.91 wt% (avg. 1.37 wt%) for apatite and titanite, and for monazite, it is 44.54 - 68.51 wt% (avg. 58.98 wt%). The chemical ages of monazite from Kudri migmatite is 1166 - 748 Ma (avg. 936 Ma; n=10) and Jarha gneiss is 1339 - 837 Ma (avg. 1088 Ma; n=13) these ages coincide with Grenville orogeny (c.1250 - 980 Ma). Hence, REE mineralization in the study area may be the result of the Grenville orogenic event. Most monazite grains are anhedral to elongate in shape and they are found as inclusion in biotite and feldspar however, some of the monazite grains are found in the intergranular space. These two contrasting modes of occurrences of monazite suggest an earlier dominantly of syngenetic (orogenic) mineralization and later with an epigenetic overprint. The geochemical analysis of these rocks shows high SiO2 and low MgO, FeO, and CaO contents indicating a felsic source which is also supported by the TAS diagram in which most of the samples fall in the granite region. The A/NK vs A/CNK plot shows the rocks are peraluminous in nature. The tectonic discrimination diagram of Y vs Nb, Ta+Nb vs Rb, and Yb vs Ta suggests that most of the rock samples fall within the plate field with few in the volcanic arc and few in the syn-collisional setting which indicates the complexity of the terrain.
Surface exchange flux measurement of HONO and NOx in agricultural fields of the Huaihe River Basin, China
Authors: Han Baobin , Qin Min , Meng Fanhao , Fang Wu , Xie Jianye , Shao Dou , Liao Zhitang , Xie Pinhua
Published: March 2024

Correspondence: Min Qin (mqin@aiofm.ac.cn)Nitrous acid (HONO) and nitrogen oxides (NOx) play a crucial role in tropospheric photochemistry by contributing to the hydroxyl radical (OH) and influencing atmospheric oxidization capacity. Recent research has found that soil HONO emissions are considered to be the main source of atmospheric HONO. Here, an aerodynamic gradient (AG) method combined with a BroadBand Cavity Enhanced Absorption Spectrometer (BBCEAS) system was developed to measure HONO and NOx emission flux from agricultural fields in the Huaihe River Basin. Measurements were taken at two different heights and included various agricultural management activities such as rotary tillage, flood irrigation, fertilization, transplanting rice seedlings, and top-dressing. For HONO and NO, upward fluxes were observed (0.07 ± 0.22 and 0.19 ± 0.53 nmol /(m2·s)), while NO2 was deposited to the ground (-0.37 ± 0.47 nmol /(m2·s)). The maximum emission fluxes of HONO and NO occurred at around 24°C, which is close to the optimal temperature (25°C) for soil microbial nitrification processes. This indicates that surface microbial processes may contribute to gas emissions. Specifically, during rotary tillage, continuous peaks in HONO flux and NO flux were observed. POH(HONO)net and POH(O3)net were 1.42 ppb/h and 1.35 ppb/h, respectively, with HONO and O3 photolysis accounted for 51% and 49% of the total yield. The peak of POH(HONO)net coincides with the peak of HONO emissions from agricultural fields, revealing the significant contribution of agricultural HONO emissions to atmospheric oxidizing capacity. After irrigation in agricultural fields, the increase in soil moisture content (~80% water filled pore space) restricts oxygen availability, thereby suppressing the HONO emission. Overall, this study provides valuable insights into the dynamics of soil HONO and NOx emissions in agricultural fields, shedding light on their environmental implications and the role of agricultural activities in atmospheric chemistry.Acknowledgments: This work was supported by the National Natural Science Foundation of China (U21A2028) and the National key Reearch and Development Program of China (2022YFC3701100). 
Modelling the base of submarine permafrost in the Canadian Beaufort Sea from seismic data and the depth of the gas hydrate stability zone 
Authors: Grob Henrik , Riedel Michael , Krastel Sebastian , Preine Jonas , Duchesne Mathieu J. , Jin Young Keun , Hong Jong Kuk
Published: March 2024

During the last 1 Ma in the Canadian Arctic, permafrost and permafrost-associated gas hydrates formed extensively due to mean annual subaerial temperatures of approximately -20°C. Following the last glaciation, a marine transgression occurred and former terrestrially exposed shelves became inundated, resulting in present submarine bottom water temperatures around -1°C. Relict submarine permafrost and gas hydrates in the Canadian Beaufort Sea are still responding to this thermal change resulting in their ongoing degradation. Thawing of permafrost and destabilisation of permafrost-associated gas hydrates can release previously trapped greenhouse gases and can lead to even further gas hydrate dissociation with important implications for the global climate. However, both the extent of the submarine permafrost and the permafrost-associated gas hydrates are still not well known. In this study, we use marine multichannel seismic data to model the base of permafrost from the depth of the base of the gas hydrate stability zone. From this depth, we estimate the theoretical gas hydrate dissociation temperature, which allows us to model the depth of the thermal base of permafrost (0°C isotherm). The base of permafrost we modelled correlates with the lower boundary of a diffuse zone of high diffractivity in seismic data suggesting the presence of ice-bearing permafrost. These results combined show that the base of permafrost still extends close to the shelf edge indicating less permafrost retreat than previously suggested. Our study provides a different approach to accessing the current depth and extent of submarine permafrost on the outermost Canadian Beaufort Shelf.
Unveiling Subsurface Secrets: Advances in Neutron Imaging for Soil Research
Authors: Kaestner Anders
Published: March 2024

As an opaque medium, soil conceals processes beneath its surface, posing a challenge for direct observation. To overcome this limitation, scientists employ imaging techniques based on radiation types capable of penetrating the soil, offering insights into its internal structures. While X-ray imaging is the most commonly used method due to its widespread availability, our focus lies on neutron imaging, an alternative and complementary modality.The distinctive advantage of neutron imaging lies in its heightened sensitivity to light elements, particularly hydrogen, and its greater penetration depth in many metals compared to X-rays. Hydrogen's significance emerges in studying the distribution of water and organic matter within soils. While the spatial and temporal resolution of neutron imaging falls slightly short of laboratory-based X-ray imaging, it operates within the same order of magnitude. Neutron imaging, often flux-limited, has prompted methodological advancements to enable time-series experiments in two and three dimensions on a scale pertinent to soil studies.Our efforts have concentrated on refining methods for conducting time-sensitive experiments, and we have pioneered the concurrent use of neutron and X-ray imaging. This dual modality approach enhances the reliability of quantitative analysis by leveraging the advantages of images from the two modalities. Quantitative analysis has been a primary focus, leading to the development of correction methods that substantially enhance the accuracy of gravimetric water content quantification based on gray levels in acquired images. The exceptional sensitivity to hydrogen enables the quantification of water content even in unresolved pores, showcasing the primary advantage of neutron imaging. Incorporating advanced denoising techniques further diminishes uncertainties in the results.Beyond imaging-related innovations, our current endeavors extend to the provision of dedicated sample environments for porous media experiments. This new equipment encompasses balances, pumps, and signal-logging devices integrated into the instrument control system. This integration improves experiment control and facilitates the logging of metadata associated with each image.In this presentation, we offer a comprehensive overview of applications benefiting from these developments, showcasing the state-of-the-art performance of neutron imaging techniques in porous media research. Our commitment to refining methodologies, advancing quantitative analysis, and providing specialized sample environments underscores our dedication to pushing the boundaries of neutron imaging for a deeper understanding of soil processes.
Detection of deep volcanic tremor sources during the 2021 Tajogaite eruption (La Palma, Canary Islands)
Authors: D'Auria Luca , Barrancos José , Falcón García Alberto , Martínez van Dorth David , Ortega Ramos Víctor , Padilla Germán D. , Preciado-Garbayo Javier , Pérez Nemesio M.
Published: March 2024

In recent years, the use of Distributed Acoustic Sensing (DAS) in seismology has gained extensive usage in different applications. A High-Fidelity DAS system (HDAS) was deployed during the 2021 Tajogaite eruption on Cumbre Volcano (La Palma, Canary Islands), allowing the recording of most of the syn-eruptive and post-eruptive seismicity. The eruption lasted from Sep. 19th until Dec. 13th of 2021. The HDAS was installed on Oct. 19th and is still operating.The HDAS was installed around 10 km from the eruptive vent and was connected to a submarine fibre optic cable directed toward Tenerife Island. Since then, the HDAS has been recording seismic with a temporal sampling rate of 100 Hz and a spatial sampling rate of 10m for a total length of 30 (first phase) and 50 km using Raman Amplification (last period).The HDAS recorded thousands of local earthquakes as well as regional and teleseism events. It was revealed to be an excellent tool for volcanic monitoring, allowing a better location of deeper events, whose location was made difficult by the small aperture of the seismic network of La Palma.The HDAS was also able to record the low-frequency (
Observer-based data assimilation for shallow water equations
Authors: Kunkel Teresa , Giesselmann Jan , Gugat Martin
Published: March 2024

We consider state estimation for a system described by the one-dimensional shallow water equations. Since in general measurements of the complete state are not available, we assume that we have measurements of only one state variable, e.g. of the water height. In order to estimate the system state from these partial measurements, we construct an observer system that is based on the shallow water equations. Distributed measurements of the water height are inserted into the observer system through source terms of Luenberger type. Our main contribution is to show exponential convergence of the state of the observer system towards the original system state in the long time limit for a 2x2-system of nonlinear hyperbolic balance laws, i.e., we reconstruct the complete system state from measurements of one state variable. The proof is based on estimating the difference between the observer system and the original system via a suitable extension of the relative energy method.Using energy-consistent coupling conditions and transforming the system to a Hamiltonian formulation, the synchronization result can be extended to star-shaped networks. This might have an application in flood modeling of river systems or control of irrigation systems.
Potential Invasion risk of the rice stem borer, Chilo suppressalis, in Europe using CLIMEX.
Authors: Hong Jinsol , Cho Kijong
Published: March 2024

Invasive pest species are the most serious threat to the resilience of agroecosystems. They cause direct damage by reducing crop yield and increasing management costs, and indirect damage through agroecosystem disturbances. To mitigate the risks posed by invasive pests, identifying their potential distribution is a crucial prerequisite. This study predicted the climatic suitability of the rice stem borer (RSB), Chilo suppressalis, within Europe using a species distribution model, CLIMEX. RSB first invaded Spain in the 1930s and has since caused significant damage, with reports of its presence in France, Hungary, and near the Caspian Sea in Russia. The overall suitability for RSB in Europe, while lower than its native region in East Asia, is predicted to be habitable across the European mainland. Notably, the climates of Mediterranean countries (e.g., Greece, Italy, France, Spain, Croatia, etc.) are expected to be sufficiently suitable for RSB habitation. Currently, RSB is also reported in Hungary, but the exact route of invasion is unclear; thus, it is necessary to investigate whether these are extensions of the existing populations in Spain and France or the result of accidental introduction through trade. Moreover, in southern Europe, where rice production is high, there is a risk of significant damage similar to that in Spain. Therefore, quarantine and prevention measures against RSB invasion are required.