bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil CO2, CH4 and N2O concentrations and fluxes in peatland forests are associated with water table level - implications of selection harvesting on soil emissions
Authors: Peltoniemi Mikko , Li Qian , Turunen Pauliina , Tupek Boris , Mäkiranta Päivi , Leppä Kersti , Müller Mitro , Rissanen Antti J. , Laiho Raija , Anttila Jani , Koskinen Markku , Lehtonen Aleksi , Ojanen Paavo , Pihlatie Mari , Sarkkola Sakari , Vainio Elisa , Mäkipää Raisa
Published: February 2023

Greenhouse gas (GHG) emissions from peatland forest soils are associated with ground water table (WT) level, which controls the vertical distribution of aerobic and anaerobic processes in soil. It has been suggested that transition from rotation forestry with ditch network maintenance (DNM) to selection harvesting would be a feasible alternative to reduce negative GHG and water impacts of peatland forestry as it raises WT and reduces aerobic decomposition of deep peat compared to mature forests. Transpiration from remaining trees would keep WT low enough for stand growth and natural regeneration without DNM. We measured vertical CO2, CH4, N2O and O2 concentration profiles in two peatland forests to provide insights on the controls of processes producing and consuming gases in the soil after harvest-induced hydrological change. The sites located on nutrient-rich peatland soils in Southern Finland, were dominated by Norway spruce, and parts of the sites were selection harvested. Selection harvesting raised WT by 14 cm relative to non-harvested controls, on average. All soil gas concentrations were associated with the proximity to the WT, but their patterns and in-soil fluxes were decoupled. CH4 and CO2 showed remarkable vertical concentration gradients, with very high values in the deepest layer due to low gas permeability of wet peat. However, CH4 was efficiently consumed in the peat layers above the WT where it reached sub-atmospheric concentrations, indicating oxidation of CH4 from both atmospheric and deeper origins. Soils maintained these functions after selection harvest. Surface peat contributed the most to soil-atmosphere CO2 flux, but harvest treatment also modestly increased the source in deeper soil. No consistent differences were observed in N2O emissions, which were the least associated with other gases. Based on our results, selection harvesting in drained nutrient-rich peatland forests without other hydrological measures limitedly reduces soil net emissions compared to non-harvested mature stands.
Effect of plant mucilage on retention and flow of water in soils with different textures
Authors: Hosseini Bahareh , Kaestner Anders , Zarebanadkouki Mohsen
Published: February 2023

Previous studies showed that mucilage extracted from chia seed enhanced retention and flow of water in dry conditions due to the intrinsic features of mucilage (increasing viscosity, water-holding capacity, and decreasing surface tension of the liquid phase). To date, there is limited information about the effect of mucilage from plant roots on the hydraulic properties of soils of different textures.In this contribution, we aimed to evaluate the effect of plant mucilage in different contents (mucilage extracted from maize roots) on the retention and flow of water in soils with contrasting textures (coarse and fine-textured soils). To this end, soils were mixed with mucilage at different contents (0, 2.5, 5, 7.5 mg dry mucilage per gr dry soil) and were packed in aluminum containers (diameters of 1 cm and height of 8 cm) as follows: the control sandy soil (the content of zero) was packed in the first 4 cm of containers followed by a 1 cm layer of treated soils with mucilage. These containers were equipped with porous plates at the bottom allowing us to drain soil from the bottom by applying suction. In the case of fine-textured soils, a 1 cm layer of treated soils with varying mucilage contents was first saturated with water and then placed on top of a 4 cm layer of dry soil inducing a big suction to dry treated soils. During soil drying, we used a time series neutron radiography technique to monitor soil water content redistribution. We used the profiles of water contents during soil drying with a combination of modeling of water flow within soils (the Richard equation) to inversely estimate the hydraulic properties of soils treated with different mucilage contents.Our data showed that maize mucilage affects the soil’s hydraulic properties. On the one hand, mucilage exuded by maize roots increased the water-holding capacity of both soils. Mucilage also impacted the hydraulic conductivity of both soils. In general, it decreased soil hydraulic conductivity of soils at the near saturation range, but it prevented a big drop in soil hydraulic conductivity as the soil dried compared to a sharper decrease observed in the control soils. Our findings showed that both effects are mucilage content dependent and the magnitude of the effects is soil texture dependent.
Seabed seismometers reveal duration and structure of longest runout sediment flows on Earth
Authors: Baker Megan , Talling Peter , Burnett Richard , Pope Ed , Ruffell Sean , Cartigny Matthieu , Dietze Michael , Urlaub Morelia , Clare Michael , Neasham Jeffrey , Silva Jacinto Ricardo , Kunath Pascal , Peirce Christine
Published: February 2023

Seafloor sediment flows (turbidity currents) form some of the largest sediment accumulations on Earth, carry globally significant volumes of organic carbon, and can damage critical seafloor infrastructure. These fast and destructive events are notoriously challenging to measure in action, as they often damage any instruments anchored within the flow. We present the first direct evidence that turbidity currents generate seismic signals which can be remotely sensed (~1-3 km away), revealing the internal structure and remarkably prolonged duration of the longest runout sediment flows on Earth. Passive Ocean Bottom Seismograph (OBS) sensors, located on terraces of the Congo Canyon, offshore West Africa, recorded thirteen turbidity currents over an 8-month period. The occurrence and timing of these turbidity currents was confirmed by nearby moorings with acoustic Doppler current profilers.Results show that turbidity currents travelling over ~1.5 m/s produce a seismic signal concentrated below 10 Hz with a sudden onset and more gentle decay. Comparison of the seismic signals with information on flow velocities from the acoustic Doppler current profilers demonstrates that the seismic signal is generated by the fast-moving front of the flow (frontal cell), which contains higher sediment concentrations compared to the slower-moving body. Long runout flows travelling >1000 km have a fast (3.7-7.6 m s-1) frontal cell, which can be 14 hours, and ~350 km long, with individual flows lasting >3 weeks. Flows travelling >1000 km eroded >1300 Mt of sediment in one year, yet had near-constant front speeds, contrary to past theory. The seismic dataset allows us to propose a fundamental new model for how turbidity currents self-sustain, where sediment fluxes into and from a dense frontal layer are near-balanced.Seismic monitoring of turbidity currents provides a new method to record these hazardous submarine flows, safely, over large areas, continuously for years yet at sub-second temporal resolution. Monitoring these processes from land would considerably ease deployment efforts and costs. Thus, work is underway investigating if terrestrial seismic stations can record submarine seafloor processes in Bute Inlet, a fjord in western Canada where independent measurement of delta-lip failures and turbidity currents can be compared to a passive seismic dataset.
3D reconstruction of atmospheric gravity waves and derivation of vertical wave parameters with tomography applied to data from two ground-based cameras observing OH airglow
Authors: Hannawald Patrick , Noll Stefan , Wüst Sabine , Bittner Michael
Published: February 2023

Atmospheric gravity waves transport energy and momentum through the atmosphere and can travel large horizontal and vertical distances from the troposphere to the mesosphere and higher. They contribute to atmospheric dynamics and among others drive the meridional pole-to-pole circulation in the mesosphere. Thus, knowing about gravity waves, their spatio-temporal characteristics, their interaction with other waves and the atmospheric background is attracting more and more attention in order to further improve climate and even meteorological models.In the upper mesosphere / lower thermosphere (UMLT) region around an altitude of 80km to 100km, OH airglow can be utilized for passive remote sensing and continuous nightly observations of atmospheric dynamics, especially of gravity waves. The OH airglow layer is a chemiluminescent layer with a strong emission in the short wave infrared spectral range (at about 1500nm) and is located at an altitude of about 86-87km with a layer halfwidth of about 4km. The OH airglow intensity is modulated by traversing atmospheric gravity waves which lead amongst others to a vertical transport of atomic oxygen. Observing the OH airglow with short-wave infrared imagers allows characterizing gravity waves. From these observations the horizontal wave parameters (horizontal wavelength, horizontal direction of propagation, etc.) can be derived.In this study we present measurements of two ground-based FAIM (Fast Airglow IMager) systems, which are cameras sensitive in the short-wave infrared region observing the OH airglow layer with a high temporal resolution. The cameras are located at Oberpfaffenhofen, Germany and Otlica, Slovenia, about 300km apart from each other and are pointing to the same volume at about 87km located in the Alpine Region above Northern Italy. We developed a novel tomographic algorithm to allow for a three-dimensional reconstruction of the airglow layer by combining images from the two viewing angles. In order to solve the highly underdetermined equation system, prior knowledge of the OH airglow layer vertical profile is needed e.g. from multi-year observations of SABER on the TIMED satellite on a statistical basis, or Gaussian and Chapman basis functions. This allows us, among others, to derive the vertical wavelength of the waves, their three-dimensional propagation direction, and their three-dimensional structure. From that knowledge, further wave parameters but also the horizontal wind along the wave propagation can be estimated via the wave’s dispersion relation.We will explain the tomographic reconstruction method, its capabilities and limits and will present a detailed case study showing a 3D-reconstructed gravity wave and the derivation of its parameters.This work received funding from the Bavarian State Ministry of the Environment and Consumer Protection.
Feedback between Water Availability and Crop Growth using a Coupled Hydrological – Crop Production Model
Authors: Chevuru Sneha , van Vliet Michelle T.H , van Beek Rens L.P.H , Droppers Bram , Aerts Jerom P.M. , Bierkens Marc F.P.
Published: February 2023

Climate change and increases in extremes, such as heatwaves and droughts, threaten crop production and food security in various regions worldwide. Irrigation is increasingly used to secure stable yields, increasing the competition for available water resources with other sectors. To assess the vulnerability of crop production under present and future drought and heatwave events, the two-sided interactions between crop growth and hydrology should be represented by a coupled model system, combining the strength of both a crop model and a global water resource model.Our main objective, therefore, is to quantify the mutual feedback between crop production and hydrology under climate extremes (i.e., droughts and heatwaves) in various regions globally over the historical period 1990-2019. To this end, we have developed a coupled hydrological-crop model framework, coupling the PCR-GLOBWB2 water resources model to the WOFOST crop model. The coupled model framework operates on high spatiotemporal resolution (daily time step up to 5 arc minutes) to assess the two-way interaction between hydrology and crop production (maize, wheat, rice, and soybean) for irrigated and rainfed agriculture. We first established a one-way coupling to evaluate the effect of the simulated water availability in terms of soil moisture of PCR-GLOBWB2 on crop production in WOFOST. Next, we established a two-way coupling in which the vegetation dynamics of WOFOST determine the evapotranspiration, which is fed back into PCR-GLOBWB2 and affects the soil moisture status. The individual WOFOST and PCR-GLOBWB2 runs and the coupled one-way and two-way model runs were compared in terms of crop production, dynamic vegetation growth, and hydrological response. The results of our simulations will be corroborated with reported yield statistics, observed discharge data, soil moisture, evaporation data obtained from satellite remote sensing, and reported annual irrigation withdrawals to assess their validity. In addition, we will evaluate the additional variance that can be explained by the more complete process description in the coupled hydrological – crop production model framework. For example, we hypothesize that the one-way coupling overestimates the crop yields under drought-heatwave events.
Turbulent transport and mixing of discharged groundwater on structured surfaces at the coastal benthic seafloor
Authors: Klettke Helena , Kandler Leonie , Brede Martin
Published: February 2023

In recent years, the discharge of groundwater has increasingly been regarded as a notable influence on the terrestrial-marine relation in the coastal zone with respect to the flux of nutrients, carbon and metals into coastal waters. Assessing the net amount of discharging groundwater is a challenge in itself, but the transport and mixing within the water column is an important topic that has been unrevealed so far.To investigate the transport and mixing processes and their dependence on wave scenario and bottom topography, we performed synchronized particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) experiments using a passive tracer in a wave channel. At the bottom of the channel, a permeable seabed model with defined roughness features, such as ripples and coarser sediment, is mounted and perfused with a fluorescent tracer fluid that resembles the discharging groundwater. Different oscillating flows with variable wave amplitude and period were investigated over each seabed model. The correlation of the measured concentration and velocity fields gives the turbulent transport quantities of the tracer fluid within the water column. Additionally, Prandtl mixing lengths can be determined from the coupled PIV and PLIF results.Results show a great influence of both, the bottom topography and the wave scenario, as well as their strong coupling through wave-seabed-interaction. Furthermore, different types of bottom roughness showed a great variation in turbulent transport, indicating that the roughness features should be treated in a more complex fashion than being modelled as scalar quantities.
Monitoring active fumaroles through electrical and magnetic survey: an application to the Pisciarelli fumarolic field (Campi Flegrei, Italy).
Authors: Troiano Antonio , De Paola Claudio , Di Giuseppe Maria Giulia , Fabozzi Carmela , Isaia Roberto
Published: February 2023

The hydrothermal area of Pisciarelli, together with the adjacent Solfatara volcano, currently represents the most active structure of the Campi Flegrei caldera in terms of degassing and seismic activity and recently manifesting significant morphological variations, including the opening of new fumarolic vents and mud emission episodes as well as changes in the geochemical characteristics of the gases/fluids. To define the structural setting of the Pisciarelli fumarolic field, Electrical Resistivity (ERT) and Time-Domain Induced Polarization (TDIP) tomographies, Self-Potential (SP), Temperature (T), PH and Magnetic (Mag) mapping have been recently realized. The geophysical tomographies furnished a 3D model of the area, which reconstructs the Pisciarelli subsurface in its area of maximum degassing, containing the main fumarole (“soffione”) and the mud pool. The comparison of the 3D model with SP, T, PH and Mag maps acquired in the area revealed the occurrence of zones characterized by intense and complex faulting and fracturing processes, affected by fluid circulation, as well as identifying sectors of the subsurface where gases accumulate as also evidenced at the surface by the presence of fumaroles and intense hydrothermal rocks alteration. In particular, the 3D model evidenced an upwelling channel in which fluids stored in a more profound reservoir rise toward the surface. Such a structure seems to be surmounted by a clay-cap formation that could govern the circulation of fluids and the abundance of gases/vapours emitted by the soffione.The conceptual model proposed for the Pisciarelli fumarolic field suggests plausible mechanisms for explaining, at the same time, the soffione activity and the role played by the deeper origin fluid/gas in the shallow fluid circulation system. In addition, the advance in the understanding of the Pisciarelli fumarolic field setting could also improve the strategy for monitoring the unrest processes in the area and evaluating the associated hazards.
Using radium isotope fingerprinting to trace hydrogeochemistry change and permafrost water cycle in cold regions
Authors: Lu Xinyan , Li Ling , Yi Lixin
Published: February 2023

Glaciers and permafrost, as core hydrological components of cold regions, are sensitive to climate change and the response in turn affects regional water resources. The ablation of glaciers and permafrost has caused severe environmental problems, including sea level rise, the release of greenhouse gases and further global warming. One poorly understood part that has so far remained underdeveloped is the change natural radioactivity related to ablation processes in cold regions. Radium isotope (223Ra, 224Ra, 226Ra and 228Ra) has been considered as an effective tracer for submarine groundwater discharge into coastal and estuarine environments over years. Unlike the coastal environments, Ra activities and activity ratios seem to show a unique distribution in cold regions. Ra will accumulate with glaciers and permafrost ablation and the activity ratios of 224Ra/228Ra (＜1 in cold regions and ＞1 in coastal regions) indicate that the radioactive equilibrium of short-time Ra isotopes has not yet been reached, which seems to be closely related to glaciers and permafrost thawing. The results of laboratory experiments show that Ra distribution between ice and water will change during freezing, and Ra exchange will occur at the ice-water interface with interaction time increasing. This study aims to explore how natural radioactivity varies in cold regions, and to provide a new tracing method for hydrological investigation in cold regions.
Geodiversity uniqueness as a new approach to quantifying geofeature patterns
Authors: Tukiainen Helena , Alahuhta Janne , García-Girón Jorge , Hjort Jan , Kemppinen Julia , Lindholm Marja , Maliniemi Tuija , Salminen Henriikka , Toivanen Maija , Heino Jani
Published: February 2023

This far, quantitative assessments of geodiversity have typically been conducted on the level of alpha geodiversity (i.e., the variety of geofeatures, such as rock types or landforms, in a location) or gamma geodiversity (i.e., sum of all geofeatures across all surveyed locations in a region of interest). These assessments give valuable information of the distribution of geodiversity but do not provide evidence on the uniqueness of the elements of geodiversity (i.e., geofeatures) at different sites. Uniqueness measures can be used to rank locations based on how exceptional they are in terms of geofeatures and when compared with other locations surveyed in a study.In this study, we demonstrate a quantitative approach to distinguish how study sites differ in their geofeature uniqueness. The methodology has been originally proposed for quantifying taxonomic uniqueness in biotic communities but we here extend its use to a geodiversity context. To illustrate the approach, we have identified geological, hydrological and geomorphological geofeatures from three areas (Rekijoki, Oulanka and Paistunturit) located across Finland, and calculated the presence/absence of each geofeature in 500 m grid cells. Founded on these grid-based datasets that cover the three study areas, we have made geodiversity uniqueness calculations. First, we calculated total beta geodiversity, from which local contribution to beta geodiversity (LCBD-g) value for each site can be subsequently derived. The LCBD-g value describes the geofeature uniqueness of each site in comparison to other sites studied in an area. Second, we calculated contributions to beta geodiversity values for each geofeature (geofeature contribution to beta geodiversity, GFCBD), describing the importance of each geofeature for geodiversity variation in the studied sites.Our results show that the uniqueness of geofeatures (LCBD-g values) varies profoundly in each of the studied areas and sites. Also, the importance of each geofeature for geodiversity variation (GFCBD value) exhibits distinct patterns, representing the varying significance of each geofeature for the total geodiversity in the studied areas. The results, especially when displayed as maps, are heuristic and an easily applicable way to flag sites that are unique in their geofeature composition. This information can complement previous approaches (such as geosite or biodiversity assessments) when prioritizing areas for nature conservation.
Assessing sea-level change of the last 300 years using tide gauge and proxy records
Authors: Hibbert Fiona D. , Marcos Marta , Valentine Andrew , Garrett Ed , Gehrels W. Roland
Published: February 2023

Detailed sea-level budgets are now available for the 20th and 21st centuries, but separating the differing contributions of sea-level rise prior to 1900 remains difficult, in part due to additional temporal and vertical uncertainties associated with proxy records, and the spatially variable nature of driving processes.We present tide gauge and proxy reconstructions of sea level since 1700, and analyse their structure using Gaussian process modelling which allows for continuous reconstructions with fully quantified uncertainties. This enables the timing of accelerations, magnitude and rates of change to be determined, and in turn enables site-specific sea-level budgets to be derived. The contribution of different driving mechanisms (e.g., glacio-isostatic adjustment and sterodynamic changes) for each site is assessed, and the evolution of the barystatic contribution for the last 300 years is evaluated.
Ocean circulation underlies the Atlantic meridional mode
Authors: Nnamchi Hyacinth , Farneti Riccardo , Keenlyside Noel , Kucharski Fred , Latif Mojib , Reintges Annika , Martin Thomas
Published: February 2023

The Atlantic meridional mode (AMM) is characterized by north-south bands of alternate anomalies in surface-ocean temperatures, and winds from colder bands to the warmer, at a periodicity of 10-15 years. The AMM has been linked to variations in Atlantic hurricanes, global surface-air temperature, and climate variability over the Sahel, South American, North American, and European. Despite these far-reaching impacts, the role of ocean circulation remains uncertain, and the prevailing AMM theories are based on thermodynamic air-sea interactions. Here we we uncover ocean-circulation variability that is linked to the AMM using twentieth century observations. Specifically, sea level-derived index of ocean circulation variabilityleads the AMM pattern by several years, through the interactions of overturning and gyre circulations with Kelvin wave anomalies that propagate from the North Atlantic to the low latitudes and by the thermocline feedback in the Atlantic cold tongue region. The peak of the sea surface temperature variability in the tropical Atlantic in turn drives inter-hemispheric atmospheric teleconnections represented by negative NAO phase over the North Atlantic. These findings imply that, rather than a passive role postulated by the prevailing thermodynamic paradigm, ocean circulation plays an active role in AMM variability.
Power System Resiliency: Weather Patterns Linked to Transmission and Distribution Outages
Authors: Ariail Isabelle , Brayshaw David , Williams Paul , Burke Claire
Published: February 2023

Weather hazards are the leading cause of power outages in the U.S. and a major contributor in Europe. Transmission lines are commonly impacted by wind and winter storms, and substations, which regulate voltage levels across the grid, are susceptible to outages caused by flooding. Recent research has begun to quantify the failure probability of power infrastructure against different weather hazards. Building on these established relationships, we seek to understand how future weather patterns will impact transmission and distribution outages in the United States. We do this by examining the weather patterns that have historically caused large-scale outages and determining how these will evolve under different climate scenarios. Additionally, forecasted outages will be compared to predicted demand to determine if there will be sufficient transmission and distribution capacity. Our results highlight locations particularly susceptible to weather-driven outages, which can help drive resilience planning as U.S. power infrastructure begins to reach the end of its lifespan.
GRACE-FO: science mission status and plans towards the extended mission phase
Authors: Flechtner Frank , Landerer Felix , Save Himanshu , Mccullough Christopher , Dahle Christoph , Bettadpur Srinivas , Gaston Robert , Snopek Krzysztof
Published: February 2023

The GRACE Follow-On mission, a partnership between NASA (US) and GFZ (Germany), will end its nominal mission lifetime in May 2023 of five years and continues the essential climate data record of mass change in the Earth system initiated in 2002 by the GRACE mission. The combined GRACE & GRACE-FO data records now span over 21 years and provide unique observations of monthly to decadal global mass changes and transport in the Earth system derived from temporal variations in the Earth’s gravity field. These observations have become indispensable for climate-related studies that enable process understanding of the evolving global water cycle, including ocean dynamics, polar ice mass changes, and near-surface and global ground water changes.In this presentation, we will discuss (1) some recent GRACE/GRACE-FO science and applications highlights, (2) key data processing and calibration approaches on GRACE-FO, with a particular focus on the accelerometer data, and also (3) the GRACE-FO mission plan to operate and collect high-quality science data through the intensifying solar cycle 25, aiming for continuity with future mass change missions. 
A study on the suitability and quantitative potential of aquifer storage and recovery and brackish water extraction in Dutch coastal areas.
Authors: America - van den Heuvel Ilja , King Jude , Bootsma Huite , Delsman Joost , Oude Essink Gualbert , de Groot - Wallast Ida
Published: February 2023

Freshwater demand will increase in the coming years due to climate change and socio-economic developments. One approach to help combat this is through aquifer storage and recovery (ASR), whereby excess fresh water is stored in the subsurface and recovered later as required. Furthermore, brackish groundwater extraction (BWE) can also be used to combat salinization and produce fresh groundwater. COASTAR is a Dutch research consortium that focuses on the use of ASR and BWE to secure sustainable access to freshwater in coastal areas. Previous research within this program produced geohydrological suitability maps at a national level through the assessment of several geohydrological factors using existing data. In this study, we test previous results using numerical validation by ‘blindly’ placing ASR and BWE well systems into the centre of 10 x 10km sub models, using 3D variable-density groundwater flow and coupled salt transport modelling. In total, 12 scenarios were simulated for approximately 170 locations in Dutch coastal areas, resulting in over 2000 model simulations. The scenarios were implemented in two different aquifers (shallow or deep) with extraction rates of 1200, 6.000, and 12.000m3/d. The resulting suitability of BWE and ASR systems at a given location was decided by how the system performs and affects the surrounding environment. A sensitivity analysis provided insights into the main geohydrological parameters and threshold values ​​applicable to ASR and BWE. Overall, results were like the pre-existing geohydrological suitability maps but offered further quantitative insights. On an international level, this knowledge can help to better understand suitability in other areas with similar subsurface characteristics. Additionally, a quick-scan analysis was performed to quantify the total potential extractable volumes for ASR and BWE. The results of this are based on maximum possible extraction/infiltration rates for each model area, by estimating the summed environmental effects of multiple wells. The method used an extrapolation approach based on the numerical model results. For this approach two factors were considered: 1) the effect of multiple extractions on the environment (changes in phreatic groundwater head), and 2) the optimal number of wells given the width of the freshwater ‘bubble’ for ASR scenarios. The quick-scan analysis showed that ASR and BWE systems have the potential to fulfill the increase in freshwater demand in the Netherlands in 2050.
PrESENCE : a participative citizen seismic network.
Authors: Turlure Mathieu , Grunberg Marc , Jund Hélène , Engels Fabien , Schlupp Antoine , Chavot Philippe , Schmittbuhl Jean
Published: February 2023

The SeismoCitizen (SismoCitoyen) project presents and tests a new paradigm of collaborative monitoring of geohazards in urban and peri-urban environments. Seismological observations are obtained using a large number of low cost internet-connected equipment (Raspberry Shake seismic sensors and associated open access data). The breakthrough strategy of the project relies on the deployment of the sensors in residences or administrative buildings of non-seismologist voluntary citizens or authorities. The aim is to use those stations to densify the french permanent seismic network, and to improve the detection and location of seismic events, in particularly small ones. The volunteers take part in a sociological survey to estimate the impact of that participative project on their perception of science. Candidates are primarily chosen according to the seismic interest of their location and for some of them to represent the social variability of the population.  Since the “Sismocitoyen” project was launched in 2018 by BCSF-Rénass and EOST (CNRS and Strasbourg University), sixty sensors have been deployed and are currently hosted by voluntary citizens in the region of the Upper Rhine Graben, in the area of Strasbourg, Mulhouse and alongside Vosges mountains. They were able to strongly improve our monitoring of the seismic events induced by a deep geothermal project close to Strasbourg where several events have been largely felt (2019-2022). The topic is becoming a major issue in the development of renewable energies that involve the subsurface as seismic hazards are of significant public concern and can have major socio-economic impacts.  With the new PrESENCE ANR project (2022-2025) we focus on seismic hazards induced by deep geothermal operations in northern Alsace and their associated societal perception.  Seventy Raspberry Shake seismic stations are being deployed since the end of 2022 and installations will continue in 2023. We will use our previous experience to improve, refine and develop all aspects such as site selection, protection of privacy and confidentiality of volunteers data and information, station calibration before deployment, data transmission and protocol to minimize data losses, stations monitoring and data analysis. During the project, interactions with the station hosts will be reinforced, in particular with convivial meetings (Stammtisch) to answer questions, present the use of the data and the results obtained.
Quantifying ballistic projectile hazards and risks due to paroxysms and major explosions at Stromboli (Italy)
Authors: Bevilacqua Andrea , Bertagnini Antonella , Pompilio Massimo , Landi Patrizia , Del Carlo Paola , Fornaciai Alessandro , Nannipieri Luca , Favalli Massimiliano , Bisson Marina , Tadini Alessandro , Aspinall Willy , Baxter Peter , Woo Gordon , Neri Augusto
Published: February 2023

Major explosions and paroxysms, respectively, have been the most powerful explosive phenomena at Stromboli in recent centuries. These two categories of explosions, although not sharply separable in terms of eruptive mechanisms and hazards, can produce ballistic projectiles affecting trails and observation sites in the summit area (both major explosions and paroxysms) as well as lower elevation areas of the volcano, down to the coast (paroxysms only). Time series analysis of reconstructed activity since the end of the XIXth Century highlights that such unordinary explosions are strongly non-homogeneous in time and often show notable temporal clustering. We perform a critical review of the volcanic catalogs produced by the Italian volcanological observatories in the last ~40 years. In this review, we evaluate the effect of uncertainties on the characterization of such major explosions, in contrast to intense ‘ordinary’ Strombolian explosions that do not eject large ballistic projectiles outside the Craters Terrace and the upper portion of Sciara del Fuoco. Where sufficient information is available for major explosions, we devise an analytical summary and explore comparative mapping of field data related to the dispersal areas of ballistic projectiles, taking into account relevant uncertainties. Using Monte Carlo simulations, we propose preliminary probabilistic hazard maps for areas potentially exposed to future events of this kind, varying the radius and angle-size of the circular sectors affected. We also evaluate lateral hazard modulation in terms of the density variability of ballistic projectiles per square meter of ground, based on literature review and spatial statistics of newly collected UAV data from the ballistic deposits of the 3rd July 2019 paroxysm on the slopes above Ginostra village. These new hazard maps, once combined with vulnerability and exposure data, allow preliminary quantitative estimates of individual risk exposure levels for guides, volcanologists, and tourists spending time in areas exposed to these unordinary events. Through a retrospective counterfactual analysis of the July 2019 eruption, we demonstrate how, in a future Strombolian paroxysm at another time of day, these risk rates might result in major casualty numbers.
Retreat analysis of a sandstone marl interbedded cliff based on a three-year remote sensing survey: A case study at La Cornalle, Switzerland
Authors: Fei Li , Choanji Tiggi , Derron Marc-Henri , Jaboyedoff Michel , Sun Chunwei , Wolff Charlotte
Published: February 2023

Rockwall retreat by rockfalls in high alpine mountains has received increasing attention due to the increased rock failure activities and the corresponding damage under global warming in the past 20 years. However, the face retreat by rockfalls of subalpine rock cliffs is not sufficiently monitored and analyzed. In the present work, the nearly vertical sandstone-marls Molasse cliff formed by the La Cornalle-Les Luges landslide was monitored by a three-year monthly drone-based SfM photogrammetry and TLS scanning to establish the rockfalls inventories. The cumulative monthly detachment volumes from the sandstone and marls layers were analyzed using the frequency-magnitude relationships fitted by a negative power law, respectively, which help to calculate the retreat rate and reveal the spatiotemporal evolution of rockfalls between these two layers. Meanwhile, the cliff retreat volume in different months was correlated to the environmental factors (e.g., air temperature, precipitation, and rock surface temperature) using linear regression. A weather station and thermal couples in the rock collected the data of these factors. As a result, this work will contribute to a better understanding of the retreat pattern and rate of freshwater Molasse walls under global warming and provide a rock detachment model on a cliff with interbedded hard and soft rock layers in the subalpine regions.
First long-term study of the Venus' Cloud Discontinuity with uninterrupted observations
Authors: Peralta Javier , Cidadão António , Morrone Luigi , Foster Clyde , Bullock Mark , Young Eliot F. , Garate-Lopez Itziar , Sánchez-Lavega Agustín , Horinouchi Takeshi , Imamura Takeshi , Kardasis Emmanuel , Yamazaki Atsushi , Watanabe Shigeto
Published: February 2023

The discontinuity/disruption is a recurrent atmospheric wave observed to propagate during decades at the deeper clouds of Venus (47-56 km above the surface), while its absence at the top of the clouds (~70 km) suggests that it might dissipate at the upper clouds and contribute to the puzzling atmospheric superrotation through wave-mean flow interaction.Thanks to a campaign of ground-based observations performed in coordination with JAXA's Akatsuki mission since December 2021 until July 2022, we aimed to undertake the longest uninterrupted monitoring of the cloud discontinuity up to date to obtain a pioneering long-term characterization of its main properties and better constrain its recurrence and lifetime. The dayside upper, middle and nightside lower clouds were studied with images taken with suitable filters acquired by Akatsuki/UVI, amateur observers and NASA's IRTF/SpeX, respectively. Hundreds of images were inspected in search of discontinuity events and to measure properties like its dimensions, orientation or rotation period.We succeeded in tracking the discontinuity at the middle clouds during 109 days without interruption. The discontinuity exhibited properties nearly identical to measurements in 2016 and 2020, with an orientation of 91º±8º, length of 4100±800, width of 500±100 km and a rotation period of 5.11±0.09 days. Ultraviolet images during 13-14 June 2022 suggest that we have witnessed for the first time a manifestation of the discontinuity at the top of the clouds during ~21 hours, facilitated by an altitude change in the critical level for this wave due to slower zonal winds.
Sinking-slab triggered formation of the giant Ordos basin in central China
Authors: Wan Neng , Liu Shaofeng , Bo Zhang
Published: February 2023

The giant Late Triassic Ordos basin, developed along northern Tethyan margin where prolonged terrane amalgamation and accretion occurred, is characterized by rapid subsidence rate along its southwestern margin, but slow and uniform subsidence rate within its interior. Its formation mechanism still remains poorly understood. Here, we use flexural simulation and 4D-geodynamic modeling to explore the potential role of basin adjacent mountain belts and deep mantle processes towards basin subsidence, respectively. Flexural backstripping of stratigraphic record spanning from 245-201 Ma, along two SW-NE trending well sections perpendicular to the southwestern margin of Ordos basin clearly demonstrates that there were long wavelength anomalous subsidence components, here termed residual subsidence, in addition to those induced by thrust loads and sediment loads. From 245-201 Ma, residual subsidence increases from 0 m to ca. 500 m and gradually decreases from southwest towards northeast. Our results indicate that basin adjacent thrust loads could act as the dominant driver for subsidence of foredeep but have limited control towards basin interior. Other mechanism is required to explain the basin-wide anomalous residual subsidence. Long-wavelength nature of residual subsidence and its general agreement, regarding both the magnitude and trend, with dynamic topography predicted by an independently designed geodynamic model suggest that the anomalous subsidence component might be of dynamic origin. We attribute this excess residual subsidence as dynamic subsidence induced by the sinking slab beneath North China plate during and after the oblique closure of Mianlue ocean between North China plate and South China plate. We argue that the Ordos basin is triggered by subduction related mantle processes while modulated by flexural loading along its margin. Our findings may also shed light on formation mechanisms of other giant basins with similar settings in East Asia.
Development of surface temperatures of alpine lakes in Austria under climate change
Authors: Enigl Katharina , Pritsch Hanna , Kurmayer Rainer
Published: February 2023

Lake Surface Temperature (LST) is a key characteristic that reflects meteorological and climatological influences on lakes. In general, there is limited LST data from high elevation lakes available as these areas are remote and not part of regular monitoring programs. Nonetheless, for the development of effective management strategies for high-altitude lakes, it is important to understand their response to climate warming. This study aims at both the reconstruction of LST back to 1998 and the projection of LSTs for 21 alpine lakes (1500-2300 m a.s.l.) in the Niedere Tauern region in Austria until the year 2100. For the determination of the relationship between atmospheric variables (temperature and precipitation), near-lake snow depth and observed LST, general additive models were trained with a daily temporal resolution for the years 1998-2003, and 2019-2020. We subsequently employed the model with the highest fit to reconstruct LSTs for the whole period 1998 to 2003. Furthermore, we estimate LST until 2100 using an ensemble of regional climate projections for the RCP2.6 (in-line with the COP 21 Paris Agreement), RCP4.5 and RCP8.5 (“worst-case”) scenario. Under the RCP8.5 scenario, the average rise for August lake surface temperatures in the far future (2071-2100) is predicted to increase by 2.3 °C compared to temperatures in the near future (2020-2049).  Consequently, the ice-free period is expected to rise on average 1-1.2—fold in the near future (2031-2060) and 1-1.5-fold in the distant future. These alterations in the lakes’ temperature regime probably affect multiple limnological parameters related to ecological quality such as primary productivity and trophic state.
Mechanisms and prediction of concurrent heatwaves and droughts in July–August over northeastern China
Authors: Li Huixin
Published: February 2023

Concurrent heatwaves and droughts that occur over northeastern China (NEC) bring severe threats to human lives and crop productions. In the present study, a probability-based index that simultaneously considers precipitation deficiency and high temperature is calculated to represent concurrent heatwaves and droughts over NEC. Based on this index, the characteristics of concurrent heatwaves and droughts over NEC in summer are investigated using the year-to-year increment approach. The results indicate that the occurrence of concurrent heatwave and drought over NEC is closely related to the Polar-Eurasian teleconnection pattern and the Pacific-Japan teleconnection pattern. Further analyses indicate that the sea ice content in the Barents Sea in March (SICBS), the La Niña-like sea surface temperature (SST) in February (SST-PC1), and the northwestern Siberia soil moisture in April (SM) are coincidently linked to the two teleconnection patterns mentioned above. Based on their corresponding physical mechanisms, these three independent predictors are chosen to construct a physical-empirical prediction model for the prediction of concurrent heatwaves and droughts over NEC. Results suggest that this physical-empirical prediction model performs well with a high correlation coefficient and a low root mean squared error between the observed and predicted concurrent heatwaves and droughts over NEC for the period 1979–2018. Moreover, the cross-validation test and independent hindcasts both suggest that the physical-empirical model proposed in the present study with the three independent predictors has good prediction skills.
Life in a dark environment – what was the physiological and calcification response of benthic foraminifera to the environmental changes of the Paleogene hyperthermals
Authors: Schmidt Daniela N. , Adebowale Monsuru , Thomas Ellen , Ridgewell Andy , Cotton Laura
Published: February 2023

The Paleocene encompasses a series of hyperthamls including the Paleocene–Eocene Thermal Maximum (PETM) and the ETM2 which represent severe disturbances of global carbon cycling and the Earth system. Responses of marine organisms included extinction, migration and evolutionary turnover, but the role of ocean acidification on deep-sea foraminiferal calcification has not yet been quantified. Using computed tomography (CT) we investigate morphological (surface area, test volume, calcite volume, chamber number) and hence calcification response in two benthic foraminiferal species, at central Pacific Site 1210 (PaleoDepth 2100m), and Southern Ocean Maud Rise Site 690 (PD 1900m), Walvis Ridge Site 1264,  and Kerguelen Plateau Site 1135 (PD ~800m) for the PETM and ETM2.The relative warming during the event was the same at all sites, suggesting that biotic differences are not likely related to differential warming. The environmental change led to reduction of test volume of both species, negatively impacting their potential ability to generate gametes. Epifaunal Nuttallides truempyi increased its surface area relative to volume in the Southern Ocean, potentially increasing its ability to forage and take up oxygen. In contrast, there is no clear pattern of change in shallow infaunal Oridorsalis umbonatus which, given sufficient food, can thrive at lower oxygen conditions. Calcite volume/test volume ratio decreased in both species during the PETM in the Southern Ocean, with the lack of response at upper abyssal depth in the Pacific possibly driven by severe oligotrophy even before the excursion. Therefore, changes in food supply during hyperthermals might have been less pronounced at upper abyssal depths in the Pacific than at the other two sites. These results contrast with published results from Walvis Ridge which showed an increase in calcification in small specimens of O. umbonatus. Food availability at the Southern Ocean sites may have supported growth as indicated by test volumes, but did not supply enough energy for calcification to mitigate against lower carbonate ion saturation during the PETM CIE.
Accelerated North Atlantic climate variability triggered by increased seasonal melt
Authors: Oltmanns Marilena , Bacon Sheldon , Holliday Penny , Moat Ben
Published: February 2023

Freshwater plays a key role in the Arctic - North Atlantic climate system. On the one hand, it has been suggested as a precursor of large-scale weather extremes and as a potential trigger of rapid climate changes in the past. On the other hand, it is, itself, a sensitive climate change indicator that increases in response to the melting cryosphere. Yet, future risks arising from enhanced glacial and sea ice melt remain difficult to assess due to the complexity of the involved ice-ocean-atmosphere feedbacks and the interference of signals on different timescales. Combining observations, models, theory, and a sophisticated statistical approach, we demonstrate the central role of freshwater anomalies in North Atlantic climate variability over the last 70 years, assess the extent to which they have been contributing to weather extremes, and discuss the risk of a more fundamental climate change under increased freshwater fluxes in future.