bluuebunny/crossref_metadata_2025 huggingface dataset:
Dating and interpreting a firn core from the East Antarctic Plateau
Authors: Sagol Furkan Kaan , Schwamborn Georg , Freitag Johannes , Kipfstuhl Sepp , Wilhelms Frank , Hörhold Maria
Published: March 2024

Detecting and understanding potential changes in annual mean temperature and accumulation rate at the East Antarctic Plateau is crucial to assess the sensitivity and future response of the Antarctic ice sheet to global warming. Due the very low accumulation rate and its spatial variability the interpretation of climate proxies from shallow firn cores with centennial to decadal time resolution is challenging. A major limitation is the available time resolution obtained by available dating approaches and a reliable assessment of its uncertainty.In this study a 204 m long firn core, B56, drilled in 2016 on the East Antarctic Plateau, is analysed. The major goal of this study is dating of the firn core by combining different dating methods on the basis of available density data, dielectric properties, and ion chromatography (non-sea-salt sulphate) data. In order to utilize density, the Herron-Langway Model is used for determining the depth-age relation. In this model temperature and snow accumulation are assumed to be constant and the relationship between the snow density and the depth below the snow surface does not change over time. Depending on the used accumulation rate, the resulting age at 200 m depth varies between 6200 to 7200 years. Secondly, the dielectric profile and non-sea-salt sulphate's (nssSO4-2) concentration data are used for constructing another depth-age model, thereby matching prominent data peaks to known volcanic eruptions that have been recorded in the past. Here, the resulting age at 200 m depth is determined to about 4400 years, which compares well to published age models of firn cores from the East Antarctic Plateau. In comparison we find all age models to be consistent within the upper 40 of meters (approximately 1000years), but the Herron-Langway model to overestimate the age at greater depths. We propose that our findings indicate changes in accumulatıon rate in the past leading to the offset in the Herron-Langway model (using a constant accumulation rate).However, by combining the dating methods we are able to not only provide a reasonable dating over the full firn core, but also to improve the time resolution of the derived age model. This will improve the interpretation of the climate proxies of this firn core and serve as a role model for other shallow firn cores from the East Antarctic Plateau.
Microseismic monitoring and characteristic analysis for underground coal mining: A case study from Xiaobaodang coal mine, China
Authors: Yu Zhichao , Tan Yuyang , Gao Kaige , Lv Yiran , He Cindy
Published: March 2024

Coal mining disrupts the stress equilibrium of the surrounding rock mass, and the rock mass cracks as a result of the changes in the stress field, releasing strain energy and causing microseismic events. Monitoring seismicitiy during coal mining is critical for ensuring safe production and preventing geological disasters. In this study, we deployed 29 surface seismic nodes above an underground coal mine in the Yulin region of Shaanxi Province, China, to monitor the mining operation for 665 hours. A large number of microseismic events have been detected from continuous monitoring data, and analyzed using event clustering, source location, and mechanism estimate. The results show that (1) the frequency and intensity of microseismic events are related to underground mining working conditions; (2) the temporal and spatial locations of the microseismic sources may be utilized for real-time tracking the location of the underground coal mining face; and (3) three rupture mechanisms of tension rupture, implosion rupture, and shear rupture reflect the triggering mechanisms of the coal pillar failure, roof breakage and movement and fault slip. 
Design of system and method on field-scale solute migration experiment for evaluating radionuclide’s migration properties at a deep borehole
Authors: Park Jiwon , Ahn Jun-Young , Yi Jong-Hwa , Cheon Jeong-Yong , Yi Myeong-Jae , Jun Seong-Chun
Published: March 2024

Disposal methods for storing high-level radioactive waste deep underground are being researched and implemented worldwide. In constructing a high-level radioactive waste disposal facility, groundwater reaction front moves and geochemical buffering capacity may be changed, affecting the long-term storage stability. Although various studies have been conducted in this regard in Korea, field-scale studies are still in shortage, in cases compared to overseas cases. This study aims to establish a long-term solute migration experiment system and experimental method for deep depths, to identify the migration and retardation characteristics of released nuclides in the deep underground environment.For field-scale tests, KURT(KAERI Underground Research Tunnel) was constructed in 2006 and in-situ solute migration tests were conducted. However, that was conducted in shallow depth, which has limitations in realizing an actual disposal environments. Therefore, the long-term solute migration experiment to be designed in this study targets underground depths, where reduced-state groundwater exists and disposal site construction is considered, to get empirical data in deep depth. The in-situ solute migration experiment system designed in this study is composed of an injection part and an extraction part. The injection unit was designed to be in charge of injecting simulated nuclides into the injection borehole. The extraction unit was designed to extract groundwater, including the injected tracer, to obtain a sample for analysis and to measure the properties of groundwater flowing through fractured rock in real-time. Both sorbing and non-sorbing tracers are used in long-term solute migration experiments. The non-sorbing tracers are suitable such as Eosin B, fluorescein sodium, and potassium bromide. The sorbent tracers which can simulate the behavior characteristics of radionuclides are suitable such as rubidium, nickel, zirconium, and samarium. Using the solute migration experiment system and experimental method designed in this study, a long-term solute migration experiment will be carred out in the deep depths around KURT, to obtain the results of the radionuclides’ migration and retardation characteristics for the deep depths.
Acknowledgements
This research was supported by the National Research Foundation of Korea(NRF) under the project 'Development of Core Technologies for the Safety of Used Nuclear Fuel Storage and Disposal; NRF-2022M2E1A1052570'.
Geology and geomorphology of the Jan 1st 2024 Mw 7.6 Noto Peninsula Earthquake: observations and context.
Authors: Malatesta Luca C. , Sueoka Shigeru , Kataoka Kyoko S. , Komatsu Tetsuya , Tsukamoto Sumiko , Bruhat Lucile , Olive Jean-Arthur
Published: March 2024

On January 1st 2024, a Mw 7.6 earthquake shook the Noto Peninsula on the Sea of Japan coast of Central Japan causing over 202 casualties and >100 missing (at the time of submission). The quake follows a period of intensifying seismic activity starting in 2020. The Mw 6.3 Oku-Noto earthquake of May 5 2023 was the previous largest event of the sequence. The Jan. 1 2024 Noto Peninsula earthquake significantly impacted the Peninsula. A large number of landslides and rockfalls dissected the road network. Liquefaction damaged infrastructure up to 150 km away from the epicenter. Meter-scale coseismic uplift modified the northern shoreline with displacement of the coastline by up to 200 m seaward discernible on SAR and aerial image data. At the time of abstract submission (Jan. 10 2024) we only have limited preliminary observations. It appears that the Noto Earthquake ruptured the same or adjacent fault to the May 5 2023 Mw 6.5 earthquake and was in the vicinity of the March 25 2007 Mw 6.9 Noto earthquake. Coseismic displacement measured geodetically shows uplift of up to +3–4 m (SAR) in the northwest of the peninsula (Wajima-shi), and +1.06 m (GPS) in the main town of Wajima-shi. The uplift magnitude decreases gradually to the SE. The uplift is near zero (SAR) or -0.3 m (GPS) on Noto Island (Nanao-shi) 30 km to the south of the town of Wajima. Surface deformation goes back to near zero (GPS) a further 20 km to the south.The coseismic deformation pattern broadly reflects the deformation recorded in the Noto landscape. Long-term moderate rock uplift in the north gives way to a complex history of long-term slow uplift around Noto Island that likely includes sustained episodes of subsidence, highlighted by its sinuous “drowned” coastline. Along the western shore (Shika-machi), marine terraces presumed to be 120 ka (last Interglacial) show a gradient in elevation also decreasing to the south. In the north, the newly emerged platform does not have a higher marine terrace counterpart. This may reflect the relationship between high wave power and moderate rock uplift resulting in the long-term retreat of the coastline and erosion of any terrace. The Noto Peninsula also holds widespread evidence of drainage reorganization that would reflect varying boundary conditions, in particular rock uplift, in deeper time beyond 100’s ka. The similarities between recent landscape morphology and coseismic displacement suggest that the Jan. 1 2024 rupture fits a recent pattern of crustal strain in Noto Peninsula (at least up to 100 ka). Earlier deformation pattern (>100’s ka) likely happened along different faults and/or at different rates as reflected by the transient drainage network.By conference time, we will present field observations collected after the rescue and emergency work is completed.
Drivers of CH4 flux quantity and variability in re-wetted European peatlands
Authors: Boodoo Kyle , Glatzel Stephan
Published: March 2024

Peatlands cover ~3% of the global land surface, yet they store 21 – 30% of the world’s soil organic carbon. Large areas of pristine peatland have been drained to facilitate traditional agricultural activity, leading to increased levels of anthropogenic greenhouse gas (GHG) emissions from these degraded peatlands. Currently, the ~12% global peatlands that are drained (~0.3% of global land area) account for ~4% of all anthropogenic GHG emissions. Within the EU, more than 50% of peatlands are degraded, with Germany having 92% of its peat soils drained for agriculture and forestry. Rewetting peatlands can reduce, or even reverse GHG emissions. While substantial research has focused on the effects on nutrient from peatland re-wetting in bogs, and within pristine Northern European environments, less work has been conducted on central European fens, and on the effect of rewetting on nitrogen in previously drained and nitrogen rich agricultural sites. We investigated the effect of three different landuses (high-, low-intensity paludiculture, wet wilderness) and two different nitrogen (N) levels on CH4 emissions from 14 different fens, located in Germany, the Netherlands and Poland, to determine landuse management optima and thresholds for reduction in GHG emissions from rewetted, formerly deeply drained agricultural peatlands. We found the highest CH4 fluxes to occur during Summer and Autumn, and lowest fluxes during Winter, across all landuses and nitrogen (N)-levels. While CH4 did significantly vary at some sites on a diurnal basis, there was no clear pattern, or definite driver of diurnal CH4 fluxes. While CH4 flux significantly increased with increasing level of paludiculture at both N-levels in Germany, CH4 flux decreased with higher intensity paludiculture at the lower-N Netherlands sites, and conversely increased with higher intensity paludiculture at high-N Polish sites. These differences in treatment effect on CH4 fluxes among the different country sites highlight the complex interaction of different drivers responsible for determining CH4 fluxes from peatlands. Overall, soil phosphorous concentration was linked to higher CH4 fluxes, while bulk density was inversely related to CH4 flux. Furthermore, general additive models showed that CH4 flux increased with soil temperature and moisture, peaking at specific carbon (C):N ratios and bulk densities. This is of relevance for management strategies, as it suggests that there is the potential for manipulation of these 4 drivers within rewetted peatlands in order to reduce future CH4 fluxes. Our results highlight the importance of maintaining minimum water table levels, and maintaining N-levels below certain thresholds in order to effectively manage CH4 fluxes, and mitigate against GHG emission contributions to global warming from current and previously drained peatlands. 
Earth’s hypsometry and what it tells us about global sea level
Authors: Pedersen Vivi Kathrine , Gomez Natalya , Mitrovica Jerry X. , Jungdal-Olesen Gustav , Andersen Jane Lund , Garbe Julius , Aschwanden Andy , Winkelmann Ricarda
Published: March 2024

Over geological time scales, the combination of solid-Earth deformation and climate-dependent surface processes have resulted in a distinct hypsometry (distribution of surface area with elevation), with the highest concentration of surface area focused near the present-day sea surface. However, this distinctive signature of Earth’s hypsometry does not constitute a single well-defined maximum at the present-day sea surface (0 m). Earth’s hypsometry also shows a prominent maximum ~5 m above the present-day sea surface. Here we explore the nature of this 5-m maximum and examine how it evolved over the last glacial cycle and may evolve moving towards a near-ice-free future. We find that the current elevation of this 5-m hypsometric maximum cannot be explained by ongoing sea-level adjustments following the last glacial cycle. Instead, we suggest that global sea level must have been higher for a significant portion of Earth’s recent multi-million-year history. Indeed, global sea level must have been higher by as much as ~9.5 m to bring this hypsometric maximum in accordance with the sea surface, to account for glacial isostatic adjustments such as ocean syphoning. This signifies that our current polar ice-sheet and sea-level state (and our global reference level) should be considered an anomaly in a geological perspective.
deadtrees.earth - an open, dynamic database for accessing, contributing, analyzing, and visualizing remote sensing-based tree mortality data.
Authors: Kattenborn Teja , Mosig Clemens , Pratima Kc , Frey Julian , Perez-Priego Oscar , Schiefer Felix , Cheng Yan , Potts Alastair , Jehle Janusch , Mälicke Mirko , Mahecha Miguel
Published: March 2024

Excessive tree mortality rates prevail in many regions of the world. Understanding tree mortality dynamics remains elusive as this multifaceted phenomenon is influenced by an interplay of abiotic and biotic factors including, but not limited to, global warming, climate extremes, pests, pathogens, and other environmental stressors. Earth observation satellites, coupled with machine learning, present a promising avenue to unravel map standing dead trees and lay the foundation for explaining the underlying dynamics.However, the lack of globally comprehensive, georeferenced training data spanning various biomes and forest types has hindered the development of a unified global product detailing tree mortality patterns. Present ground-based observations, e.g., sourced from national inventories, are often sparse, lack standardization, and spatial specificity. Alternatively, aerial imagery captured via drones or airplanes in concert with computer vision methods offers a potent resource for mapping standing deadwood with high precision and efficiency on local scales. Such products can subsequently be used to train models based on satellite data to infer standing deadwood on large spatial scales.In pursuit of harnessing this potential to enhance our global comprehension of tree mortality patterns, we initiated the development of a dynamic database (https://deadtrees.earth), which enables to 1) upload and download aerial imagery with optional labels on standing deadwood, 2) automatically detect (semantic segmentation) standing dead trees in uploaded aerial imagery through a generic detection computer vision model, 3) Visualization and download of extensive spatiotemporal tree mortality products derived from extrapolating standing deadwood using Earth observation data.This presentation provides an in-depth overview of the deadtrees.earth database, outlining its motivation, current status, and future perspectives. By integrating Earth observation, machine learning, and ground-based data sources, this initiative aims to bridge the existing gaps in understanding global tree mortality dynamics, fostering a comprehensive and accessible resource for researchers and stakeholders alike.
Differences of nitrogen cycle microbes and nitrous oxide emissions from natural and degraded tropical peatland sites in Malaysia
Authors: Kuusemets Laura , Mander Ülo , Öpik Maarja , Melling Lulie , Soosaar Kaido , Kasak Kuno , Espenberg Mikk
Published: March 2024

Tropical peatlands in Southeast Asia are severe threats due to rapid changes in land-cover. Estimates suggest that approximately 25% of natural peatlands in Malaysia have been converted for large-scale agro-industrial development in the last two decades, primarily driven by the rapid expansion of oil palm cultivation. These intense and rapid land-use changes contribute to adverse ecological impacts, including increased greenhouse gas (GHG) emissions, soil degradation, deforestation and the loss of biodiversity. The aim of the study was to assess the genetic potential of nitrogen (N) transformation processes by quantifying functional marker genes of N cycle and measuring nitrous oxide (N2O) emissions from natural tropical peatland and oil palm plantation. This was conducted to understand the effect of land-cover changes on microbial N transformation processes and gaseous N emissions, using the closed chamber method and quantitative polymerase chain reaction (qPCR) analysis. N2O emissions were measured in the natural tropical peatland forest in Maludam (Sarawak, Malaysia) and in the oil palm plantation on peat soil in Betong (Sarawak, Malaysia) in September 2022. qPCR was used to measure the abundance of bacterial and archaeal specific 16S rRNA, nitrification (AOB, AOA and COMAMMOX amoA genes), denitrification (nirK, nirS, nosZ clade I and nosZ clade II genes) and dissimilatory nitrate reduction to ammonium (DNRA; nrfA gene) marker genes in the collected soil, litter and leaf samples.The average soil N2O emissions were relatively higher from the oil palm plantation, ranging from 2.04 to 131.9 µg N m-2 h-1. Soil N2O emissions from the natural peatland forest were negligible. Quantification of N cycle genes revealed variations in the microbiome between natural peatland and deep-drained oil palm plantation. The microbial analysis showed that the archaeal abundance in leaves did not vary significantly between the two sites, but the abundance of bacteria in leaves was higher in the oil palm plantation. The abundance of denitrifying microorganisms was significantly higher in the natural peatland soil compared to the peat soil in the oil palm plantation. However, the abundances of bacterial amoA and archaeal amoA were found to be lower in the soil of natural site compared to the soil in oil palm plantation, suggesting a higher genetic potential of nitrification in the oil palm plantation. In addition, microbes possessing the archaeal amoA gene seemed to be the primary nitrifiers in the soil of oil palm plantation. The study’s findings indicate that hydrological interventions cause significant changes in the microbial N cycle and N2O emissions of tropical peatlands.
Cenozoic clockwise rotation of the northeastern Tibetan Plateau
Authors: Huang Rong , Wang Weitao
Published: March 2024

Vertical–axis rotations recorded by paleomagnetic results from the northeastern Tibetan Plateau afford new insights into the tectonic processes related to the growth of the Tibetan Plateau. The Qinling Mountain is a special orogenic belt that bridges the crustal shortening of the northeastern margin of the Tibetan Plateau in the west with the extensional North China block in the east. In this study, we focus on the intermountain basins across the West Qinling Mountain. We present geochronological and paleomagnetic results from the basalt and redbed sequences from the Cretaceous–Cenozoic basins within the West Qinling Mountain. Constrained by precise ages, our paleomagnetic results reveal that approximately 10–20◦ clockwise vertical–axis rotation occurred across the West Qinling Mountain during the middle to late Miocene, indicating a significant period of outward growth of the Tibetan Plateau.
Combined study of the geological and geotechnical measurements of fine-grained sediments at a planned offshore wind farm extension area in Finland
Authors: Saresma Maarit , Mohapatra Debasis , Mohammadi Hasanbarough Saeideh , Solowski Wojciech , Virtasalo Joonas
Published: March 2024

Offshore renewable energy production is increasing rapidly in Finland. Most of the planned offshore renewable energy, particularly offshore wind farms are located in western Finnish waters relatively close to the coast. Shallow water enables optimization of the location of the wind turbine foundations however the ground conditions can change quickly because of the complex glacial and post-glacial sediment cover. Knowledge of the geological and geotechnical properties of the subsurface sediments contributes to safe and cost-effective design of offshore structures.
This study focuses on analyzing the geological and geotechnical variability of the fine-grained sediments at a planned offshore wind farm extension area in western Finland. The sediments and their geotechnical properties in the study site vary in depth and character on a comparably small scale depending on their depositional environment. The main geological characteristics play an important role while interpreting the geotechnical properties, e.g., soil undrained shear strength. The study shows seismoacoustic sub-bottom profiles combined with geological and geotechnical index properties from sediment coring supplemented by dynamic undrained shear strength from free fall cone penetrometer (FFCPT) tests. FFCPT tests can successfully identify sediment units and support sub-bottom profile interpretation. Ground-truthing the actual shear strength values from the FFCPT by laboratory soil testing is discussed.
This research is part of the Geomeasure project, funded by the Research Council of Finland (Grant No. 347602).
The influence of irrigation on root zone storage capacity
Authors: van der Ent Ruud , van Oorschot Fransje , Alessandri Andrea , Hrachowitz Markus
Published: March 2024

Vegetation plays a crucial role in regulating the water cycle through transpiration, which is the water flux from the subsurface to the atmosphere via vegetation roots. The amount and timing of transpiration is controlled by the interplay of seasonal energy and water supply. The latter strongly depends on the size of the root zone storage capacity (Sr) which represents the maximum accessible volume of water that vegetation can use for transpiration. Sr is primarily influenced by hydro-climatic conditions as vegetation optimizes its root system in a way it can guarantee water uptake and overcome dry periods. Sr estimates are commonly derived from root zone water deficits that result from the phase shift between the seasonal signals of root zone water inflow (i.e., precipitation) and outflow (i.e., evaporation). In irrigated croplands, irrigation water serves as an additional input into the root zone. However, this aspect has been ignored in many studies, and the extent to which irrigation influences Sr estimates was never comprehensively quantified. In this study, our objective is to quantify the influence of irrigation on Sr and identify the regional differences therein. To this aim, we integrated two irrigation methods, based on irrigation water use and irrigated area fractions, respectively, into the Sr estimation. We evaluated the effects in comparison to Sr estimates that do not consider irrigation for a sample of 4511 catchments globally with varying degrees of irrigation activities. Our results show that Sr consistently decreased when considering irrigation with a larger effect in catchments with a larger irrigated area. For catchments with an irrigated area fraction exceeding 10%, the median decrease of Sr was 17 mm and 22 mm for the two methods, corresponding to 12% and 17%, respectively. Sr decreased the most for catchments in tropical climates. However, the relative decrease was the largest in catchments in temperate climates. Our results demonstrate, for the first time, that irrigation has a considerable influence on Sr estimates over irrigated croplands. This effect is as strong as the effects of snow melt that were previously documented in catchments that have a considerable amount of precipitation falling as snow.A manuscript associated with this abstract is available as preprint:van Oorschot, F., van der Ent, R. J., Alessandri, A., and Hrachowitz, M.: Influence of irrigation on root zone storage capacity estimation, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2023-2622, 2023.
Pyrite trace element proxies for magmatic volatile influx in submarine subduction-related hydrothermal systems
Authors: Falkenberg Jan J. , Keith Manuel , Haase Karsten M. , Klemd Reiner , Kutzschbach Martin , Grosche Anna , Scicchitano Maria Rosa , Strauss Harald , Kim Jonguk
Published: March 2024

Seafloor massive sulfides represent modern analogues to ancient volcanogenic massive sulfide deposits, which can be particularly enriched in volatile and precious metals (e.g., Te, Au, Ag, Cu, Bi, Se) in subduction-related systems. However, it remains unclear whether the influx of magmatic volatiles has a systematic control on the metal endowment of submarine hydrothermal mineralization on the plate-tectonic scale. Using a novel microanalytical approach based on the coupling of SIMS δ34S with trace element LA-ICP-MS on a scale of ~25 µm in pyrite from 11 submarine hydrothermal systems, we could demonstrate for the first time that the Te, As, and Sb contents and the ratios of these elements vary systematically with the δ34S composition of hydrothermal pyrite and native S. In contrast to trace element concentrations, Te/As and Te/Sb show a more significant correlation with δ34S in pyrite, indicating that element ratios provide a more robust record of metal sourcing. On this basis, we define a quantitative trace element threshold of high Te/As (>0.004) and Te/Sb (>0.6) ratios in pyrite that can be used to identify the influx of magmatic volatiles to submarine subduction-related hydrothermal systems independent of δ34S isotope measurements. Two-component fluid mixing simulations further suggest that even small amounts (
Fault Lines to Frontlines: Geomechanical Challenges of Sustainable Energy Transition
Authors: Rizzo Roberto Emanuele , Keir Derek Boswell , Busch Andreas , Forbes Inskip Nathaniel , Healy David , Gudbrandsson Snorri , De Siena Luca , Vannucchi Paola
Published: March 2024

The transition to sustainable energy systems introduces a complex landscape, wherein geothermal energy and carbon dioxide storage (CCS) play critical roles. These activities target geological formations that are always faulted and fractured. As the focus intensifies on alternative energy systems for decarbonisation, understanding these faulted rocks in the subsurface gains great importance. Fault and fracture systems can act not only as conduits for fluid flow but they can also be zones of mechanical weakness that may respond dynamically to fluid pressure changes due to natural geological processes or anthropogenic activities, such as CCS or geothermal extraction. This dual role of fault and fracture systems as pathways for fluid flow and as potential triggers for mechanical failure makes their study a cornerstone of sustainable subsurface resource management. The challenge lies in accurately characterising the permeability of these systems and estimating their mechanical behaviour under changing stress conditions. This is vital for ensuring the integrity and efficacy of operations like CCS and geothermal energy extraction, where even slight variations in fluid pressure can have significant implications. For instance, experiences from the fluid injection experiment for an enhanced geothermal system in Basel, Switzerland, and the In Salah CCS pilot site in Algeria highlight how minor changes in pore fluid pressures (as little as 10 MPa) can induce leakage and/or seismic activities. We highlight selected case studies from both active and prospective CCS and geothermal sites (in Svalbard and Mid-Ethiopian Ridge, respectively). These examples illustrate methodologies in fault stability analysis and geomechanical characterization, shedding light on the relationship between fluid flow, stress alterations, and rock mechanics in faulted and fractured formations. By coupling empirical data with modelling techniques, we present strategies to mitigate risks and enhance the efficiency of subsurface decarbonisation efforts.
Investigation into rockslides by the adaptive rock discrete fracture analysis (RDFA) method
Authors: Gong Bin , Zhao Tao
Published: March 2024

The rock discrete fracture analysis (RDFA) method was proposed as a combination of the rock failure process analysis method and the discrete element method. Leveraging the statistical strength theory and contact mechanics, it can effectively capture the intricate continuum-discontinuum behaviors inherent in rock mechanics, encompassing fracture and fragmentation phenomena. Enabled by a sophisticated nodal updating scheme, RDFA can dynamically adjust nodes at critical crack tips in accordance with strength criteria, facilitating accurate modeling of zero-thickness crack initiation and propagation. Noteworthy is its capacity to accommodate the inherent heterogeneity of rock masses, enabling holistic consideration of localized damage and fine crack development. Rigorously validated through the Brazilian disc and uniaxial compression tests, RDFA consistently aligns with the analytical solutions and experimental data. After that, it was applied to analyze the rockslide characteristics at the Anshan Road station in the Qingdao metro, China, and illuminated crucial insights. The results show that in the presence of 60° oriented joints with 5m spacing, the high stress concentration primarily emerged at the slope toe, leading to the localized tensile damage and the formation of a sliding surface. Subsequent rock sliding induced compression and collision among blocks, precipitating continuous failure within the sliding body. Additionally, the presence of intermittent joints notably contributed to progressive rockslide, particularly triggering the localized failures in the lower part of the slope.
The influence of sputtering and sublimation on Kuiper belt dust trajectories
Authors: Mann Ingrid , Poppe Andrew , Gjelsvik Amalie , Li Aigen
Published: March 2024

NASA’s New Horizons spacecraft is currently exploring the outer solar system and passes the Kuiper Belt. The Student Dust Counter (SDC) onboard New Horizons has measured the flux of interplanetary dust grains throughout nearly the entire mission so far. The observed dust flux around 50 AU at the expected edge of the the Kuipe belt is higher than predicted. A possible explanation could lie in the trajetcries of the dust particles that can be pushed out to large distances by radiation pressure force. We investigate the trajectories of ice particles in the Kuiper belt which are more strongly influenced by radiation pressure when their sizes are reduced, due to mass loss caused by sublimation, solar wind sputtering and photo sputtering. The results suggest that the changing size of the particles may lead to a more stable and confined dust ring in the Solar System's Kuiper Belt. 
Monitoring, reporting and verification for a marine carbon dioxide removal process: a case study
Authors: Comazzi Federico , Cappello Stefano , Campo Francesco , Grosso Mario , Caserini Stefano
Published: March 2024

To achieve ambitious climate change goal as the one set by the Paris Agreement, Carbon Dioxide Removal (CDR) processes should be deployed in addition to rapid emission reductions. The process of Monitoring, Reporting, and Verification (MRV) is pivotal to certifying the effectiveness of carbon removal technologies for a voluntary or regulated CDR market.The MRV process consists of monitoring the amount of greenhouse gas removed by a CDR activity and reporting the results of the monitoring to a third party. The third party then verifies the reporting of the results.MRV applied to marine CDR (mCDR) that are facing challenges to precisely count the positive impact of those technologies ensuring the additionality and the long term durability of the CO2 removal.Here, the development and the application of a new mMRV protocol for a new approach to Ocean Alkalinity Enhancement (OAE) with equilibrated pH. The challenges faced and still to be addressed will be analyzed for all the steps of MRV, and the advantages in the discharge of a pH-equilibrated alkaline solution, compared to the traditional  OAE approach where a reactive substance such as slaked lime is discharged, are discussed.A specific measuring procedure is established for assessing the net carbon removal through specific sensors for measuring parameters, i.e., pH, Turbidity, Suspended Solid, Conductivity, CO2 detector.The procedure for the reporting phase, where data will be automatically managed by the process internal software are presented, as well as the Verification procedure, performed by a third-party certifier that will evaluate and verify the compliance of the process to the process’ specs.
Integrating UAV data and soil-crop modelling for Enhanced Soil Health Monitoring
Authors: Vavlas Nikolaos-Christos , Kooistra Lammert , van Egmond Fenny , De Deyn Gerlinde
Published: March 2024

The necessity of soil health monitoring is paramount in reversing soil degradation and promoting sustainable farming. Including cover crops in the crop rotation is one of the sustainable soil management practices contributing to soil health. Cover crops contribute to soil health by nutrient retention and carbon accumulation during their growth and return of organic matter to the soil upon their incorporation. During monitoring, the sampling frequency can change from annual in the case of SOC to weekly or daily for fertilization and irrigation. Remote sensing techniques offer a solution, enabling the monitoring of vegetation over time and space, thereby enhancing our understanding of the impact of cover crops on the main crop. However, this technology makes it possible to see the surface of the field which can assist with the above-ground changes of the system. Process-based modelling and data assimilation can subsequently link the above-ground component with soil functions. In-situ data collection that includes crop characteristics such as biomass and N-uptake is essential both for transforming remote sensing data into crop characteristics and for calibrating models. Using Unmanned Aerial Vehicles (UAVs) can potentially collect data at high frequency, which can be used to enhance soil process modelling. The development of this UAV-based method has the potential to be scaled up to a satellite level in the future.In our research, we have combined the study of nutrient cycling and the effect of cover crops on soil health. To achieve this, we have used the WOFOST-SWAP-ANIMO model to simulate the varying influence of cover crop monocultures and mixtures on Soil Organic Carbon (SOC) and Nitrogen cycling in a 7-year crop rotation on sandy soil. The model simulates vegetation characteristics such as biomass, leaf area index, and yield, as well as soil moisture and mineral Nitrogen concentrations. This will give us a good estimation of the vegetation input into the soil as well as the nutrient uptake from both cover crops and main crops. Soil sampling is also important to model calibration/validation to be able to simulate the N dynamics of biological activity under the surface. Our findings suggest that the model, in conjunction with UAV data and field sensors, can effectively monitor soil health indicators crucial for field management practice selection, such as the Carbon cycle and Nitrogen use efficiency.
Examining the Reliability Gap: Insights into Forest Canopy Height Using Evidential Deep Learning
Authors: Kugler Lucas , Wessollek Christine , Forkel Matthias
Published: March 2024

Estimating forest canopy height is a crucial aspect in quantifying forest biomass, carbon stocks, monitoring forest degradation, and succession or restoration initiatives. Operational forest structure monitoring on a large scale involves various satellite sensors and datasets as well as large geographical variations. Challenges remain in obtaining uniformly representative ground truth data across diverse areas, phenology phases and forest types. Recently deep learning models are more frequently used to map forest canopy height at large scales by e.g., using sample observations from space-borne LiDAR sensors as training data. Training deep learning models rely on large amounts of data but are often trained on limited source domain data that is confined to cover the above-mentioned aspects. However, during testing, models may encounter out-of-distribution samples, leading to unexpected model behaviour and predictions. This vulnerability reduces the reliability of deterministic Deep Learning architectures, and finally, reliance on predictions without confidence indicators can result in misleading scientific conclusions or potentially under-informed policy decisions. Due to the varying ways of data processing, differences in forest canopy height products emerge, and hence product inter-comparison is often difficult and debatable. Existing products often do not provide any information about the confidence of their predictions.To address this lack of confidence, we employ evidential deep Learning, adapting non-Bayesian architectures to estimate forest height and associated evidence. This approach aims to capture both aleatoric and epistemic uncertainties in areas with different forest structures investigating study areas , by incorporating evidential priors into the Gaussian likelihood function. Our method involves training a myriad of deep learning architectures including a basic CNN and Residual neuronal nets for regression to infer the hyperparameters of the evidential distribution.Alongside other current studies, Sentinel-2 and Sentinel-1 satellite imagery serve as predictors for forest canopy height, with reference data obtained from the Global Ecosystem Dynamics Investigation (GEDI) LiDAR instrument on the International Space Station. The research explores the effects of distributional data shifts on canopy height predictions and identifies footprint samples where prediction uncertainty increases, representing different forest structures.The application of evidential deep learning could extend far beyond this study, potentially benefiting various tasks in estimating biophysical parameters from remote sensing.
Assessing the Mitigation Potential and Ecological Impacts of Carbon Dioxide Removal Technologies on Ocean Ecosystems
Authors: Tran Giang , Jeltsch-Thömmes Aurich , Keller David , Oschlies Andreas , Joos Fortunat
Published: March 2024

Climate change poses a critical threat to global ecosystems and human well-being, necessitating innovative solutions for carbon dioxide (CO2) mitigation. This study employs the UVic-ESCM, an Earth system model of intermediate complexity, to investigate the potential and possible side effects of two marine-based CO2 removal techniques, namely ocean alkalinity enhancement and macroalgae farming and sinking. Additionally, simulations from Bern3D-LPX for ocean alkalinity enhancement provide a model comparison.Focusing on not only warming but also acidification and deoxygenation, the research aims to compare the theoretical deployment of these techniques in an emission-driven overshoot scenario (SSP5-3.4).To encompass uncertainty due to model parameters, we analyzed a perturbed parameter ensemble constrained by observations. Preliminary findings indicate that both techniques show promise in mitigating atmospheric CO2 concentrations, with variations in their effects on climate and oceanic conditions. Both techniques show small cooling potential despite the large-scale theoretical deployment. While they do not provide an alternative to emission reductions, they could be beneficial in combating other human-induced stressors in the marine ecosystem. Both techniques demonstrate a potential to counteract ocean acidification, but we find that macroalgae farming and sinking contributes to localized deoxygenation.This study contributes to the ongoing discourse on so-called ‘nature-based’ solutions for climate change mitigation by offering a nuanced evaluation of the theoretical upper potential in multiple mitigation dimensions as well as side effects of ocean alkalinity enhancement and macroalgae farming and sinking. The outcomes aim to inform future research directions and decision-making processes towards the development of effective and ecologically sustainable carbon dioxide removal strategies.
Assessment of resuspend bottom material into the water column during the possible removal of dumped ammunition from the sea.
Authors: Jakacki Jaromir , Muzyka Maciej
Published: March 2024

Ammunition dumped in the sea generates specific problems related to decision making about what will happen in the event of a leak and the consequences when it will be taken out of the sea. One of the reasons for the difficulties in making decisions is the lack of knowledge about the dumped material (it may be, for example, chemical munitions), the level of pollution in the surrounding area, and the mobility of the sediments in which it was found. Therefore, the main goal of this work is to develop a model that will be an element of the system providing information on the mobility of sediments and thus the possibility of spreading the contaminated fraction. The whole will consist of several elements, including a demonstrator for analysing the properties of sediments. An important element is to get the real value of the threshold shear stress to calculate the current speed required to resuspend individual particles or upper sediment layers. Additionally, the properties of the sediment will be determined on the basis of the in situ collected samples. All this will allow the development of a model providing information on the mobility of bottom material introduced into the sea depths and, consequently, the contaminated area. The work concerns preliminary activities, and the concept of the system along with preliminary results will be presented. At this stage, the shear stress threshold measurement also requires tuning. It is important to add that this is to be part of a larger system to support the selection of the most appropriate approach when ammunition is found in the Baltic Sea. The results are part of the EU MARTERA project PROBANNT. Study partially financed by the National Centre for Research and Development, Poland
Intraspecific variation of spring and autumn phenology in Fagus sylvatica
Authors: Beil Ilka , Pluquette Nadine , Willenbockel Nora , Kreyling Jürgen
Published: March 2024

The timing of spring leaf out and autumn senescence needs to be well adapted to the climate at the particular site to ensure precise alignment with the change of the seasons.  From a tree species with a large distribution range covering wide parts of Europe, we would expect substantial variation the phenological characteristic and in the chilling requirements of different provenances. If climate is getting warmer and winters are getting shorter, the local adaptation to might not fit future climate anymore, so that the trees cannot take advantage out of an early start of the growing season or a late warm autumn.In a provenance trial with young beech seedlings, we quantified the differences between spring leaf out and autumn senescence of the provenances and individuals. We further asked which climate parameters were the evolutionary drivers for those phenological characteristics. And we investigated, if there is a correlation between phenological timing and growth, assuming that early flushing and late colouring individuals would utilize the growing season better.The difference between the earliest and the latest provenance in spring leaf out was 8 days and in autumn senescence 17 days. For spring leaf out, we tested for several climate parameters and found that the longer the winter with more days between 0 and 10°C at the place of origin, the later the trees leafed out in our common garden. This climate parameter reflects nicely the often-used quantification of chilling. So, at places were typically more chilling time occurs over winter, the trees developed higher chilling requirements.  But also, the lower the minimum temperature in winter at the place of origin, the earlier they leafed out in our common garden, which is less intuitive. For autumn, eastern provenances coloured their leaves earlier than western provenances if grown under the same climate. The growth of the seedlings will be measured in winter 2023/2024 and will be evaluated in relation to their provenances and to their phenological characteristics in the presentation.
Tracing diurnal variations of carbon and water cycle tracers over a tropical and temperate forest
Authors: Koren Gerbrand , Faassen Kim A. P. , González-Armas Raquel , Adnew Getachew Agmuas , van Asperen Hella , de Boer Hugo , Botía Santiago , Hartogensis Oscar , Hulsman Lucas , Hutjes Ronald W. A. , Jones Sam P. , Komiya Shujiro , Luijkx Ingrid T. , Mol Wouter , van der Molen Michiel , Moonen Robbert , Röckmann Thomas , Vilà-Guerau de Arellano Jordi
Published: March 2024

Diurnal temperature and carbon dioxide ranges are key metrics to quantify the impact of regional climate changes in forests. These ranges depend on biophysical processes, surface heat, water and carbon exchange, and boundary-layer dynamics. A crucial and elusive process is the entrainment of air from the free troposphere and residual air layers into the atmospheric boundary layer. Here we provide observational constraints on entrainment for two contrasting measurement sites: the Amazon Tall Tower Observatory (ATTO) in central Amazonia and the Loobos flux tower (NL-Loo) in a temperate forest in the Netherlands. We used radio soundings, air samples from tall towers and aircraft data in combination with surface air measurements and ecophysiological data. Fluxes and concentrations were measured for biophysical-process tracers  CO2, O2/N2, δ13C, δ18O (in CO2) and δ18O (in water). These novel tracers are proposed to partition gross carbon and water fluxes and for estimating plant properties and we present a unique dataset with our interpretation. Our analysis enables us to unravel the role of entrainment on the diurnal ranges and how this is controlled by surface and entrainment fluxes. By means of a coupled forest-atmosphere model constrained by the comprehensive observations, we perform a sensitivity study on the surface flux partitioning (photosynthesis versus soil respiration; soil evaporation versus plant transpiration, sensible versus heat flux) under a wide range of leaf traits, surface and boundary-layer dynamic conditions. Our results are useful to assess the performance of carbon-climate models in tropical and temperate forests.