bluuebunny/crossref_metadata_2025 huggingface dataset:
The Fresnel Platform for Greater Paris: online tool to Dynamically Manage Multiscale Urban Resilience
Authors: Drouen Guillaume , Schertzer Daniel , Monier Laurent , Willinger Bernard , Tisserand Bruno
Published: March 2021

The general goal of the Fresnel platform of Ecole des Ponts ParisTech is to develop research and innovation on multiscale urban resilience. It is therefore conceived as a SaaS (Sofware as a Service) plaform providing data over a wide range of space-time scales and  appropriate softwares to analyse and simulate them over this range. 

The most recent development is the radar component RadX V3.0 that is now operational at https://radx.enpc.fr. It provides an easy access to various products based on precipitation measurement performed at the radial scale of 128 m by the ENPC polarimetric X-band radar. Using reliable and open source libraries it features a real-time radar display available to the general public and professionals who can freely access the precipitation data over a large part of Île-de-France region from their web browser (desktop and mobile). Another major component is the "analysis" section where scientists and managers  can define and select rainfall events in a interactive calendar and then analyse rainfall data throught different tools such as an interactive map with time control and dynamically genetared hyetograms.
For more refined spatial analysis registered users can also introduce their own shapefiles containing catchments and subcatchments, as well as to extract data and maps. They can also pinpoint a radar pixel to display hyetogram from a local area, this versatily on spatial and temporal selections allows for very precise analysis.

The application allows for different radar product analysis like DPSRI (Dual Polarization Surface Rainfall Intensity) and SRI (Surface Rainfall Intensity).These complementary products enhance the case studies analysis and give weather scientists more tools directly available from their web browser. 

Further software developments include high resolution hydrological modeling and a multifractal toolbox to estimate the scale invariant features of the precipitation and other fields (e.g. landuse). These developments are performed in close contacts and feedbacks from the scientific and professional world and they greatly benefit from the support of the Chair “Hydrology for Resilient Cities” (https://hmco.enpc.fr/portfolio-archive/chair-hydrology-for-resilient-cities/) endowed by the world leader industrial in water management and from previous EU framework programmes.
Estimation of copper ore deposit parameters – case study of Rudna Mine mining block R-1 (SW part of Poland) using geostatistics
Authors: Namysłowska-Wilczyńska Barbara
Published: March 2021

This geostatistical study investigates the variation in the basic geological parameters of the lithologically varied deposit in mining block R-1 in the west (W) part of the Rudna Mine (the region Lubin – Sieroszowice, SW part of Poland).

Data obtained from the sampling (sample size N = 708) of excavations in block R-1 were the input for the spatial analyses. The data are the results of chemical analyses of the Cu content in the (recoverable) deposit series, carried out on channel samples and drilled core samples, taken systematically at every 15-20 m in the headings.

The deposit profile comprises various rock formations, such as: mineralized Weissliegend sandstones, intensively mineralized upper Permian dolomitic-loamy and loamy copper-bearing schists and carbonate rocks: loamy dolomite, striped dolomite and limy dolomite, of various thickness. No schists formed in some parts of block R-1, which are referred to as the schistless area. The deposit series here is considerably less mineralized (comparing with other mining blocks) even though the mineralization thickness of the sandstone and carbonate rocks reaches as much as 20 m.

The variation in the Cu content and thickness of the recoverable deposit and the estimated averages Z* of the above parameters were modelled using the variogram function and the ordinary (block) kriging technique. The efficiency of the estimations was characterized.

As part of the further spatial analyses the Zs values of the analysed deposit parameters were simulated using the conditional turning bands simulation. Confidence intervals for the values of averages based on the estimated averages Z* and averages  based on the simulated values (realizations) Zs, showing the uncertainty of the estimations and simulations, were calculated.

The results of the analyses clearly indicate the shifting of the mineralized zone (the mineralizing solutions), sometimes into the sandstones while spreading throughout the floor of calcareous-dolomitic formations and sometimes into the carbonate rocks, partly entering the roof layers of sandstones. It can be concluded that the process of deposit formation and copper mineralization variation had a multiphase character and the lateral and vertical relocation of the valuable metal ores could play a significant role.

The combination of various geostatistical techniques - estimation and simulation - will allow for more effective management of natural resources of mineral resources, including copper ore deposits.
Modelling Study of the Summer Time Arctic Liquid Clouds
Authors: Ghahreman Roya , Gong Wanmin , Beagley Stephen R. , Akingunola Ayodeji , Makar Paul A.
Published: March 2021

Investigation of the cloud microphysics is carried out by using a fully coupled version of GEM-MACH, the Environment and Climate Change Canada’s (ECCC) online air quality forecast model, (Global Environmental Multiscale–Modelling Air quality and Chemistry) for the Arctic domain during summer 2014. Simulation results indicate that model is capable of simulating the low clouds prevailing in summertime Arctic, particularly thin water clouds (or clouds with liquid water path < 50 g m-2), which have a significant effect on cloud radiative forcing in the Arctic.

Model simulations are also compared with the July 2014 NETCARE field campaign aircraft observations based from Resolute NU. The field campaign consisted of two periods with distinct metrological conditions: relatively pristine and relatively polluted Arctic atmosphere with the influence of transport from lower latitudes. For the relatively polluted period, simulations of cloud’s microphysics suggested more and smaller droplets with higher liquid water content (LWC), and hence lower precipitation and longer cloud lifetime. The model agrees well with the observation results showing that aerosols in the size range of 50-100 nm are commonly activated in the summer Arctic, with even smaller aerosols (< 50 nm) being activated during the pristine period.
Assessing ground deformation in the Central Andes (NW Argentina) with Interferometric Synthetic Aperture Radar analyses: First results of SAOCOM data and Sentinel-1 data
Authors: Viotto Sofia , Bookhagen Bodo , Toyos Guillermo , Torrusio Sandra
Published: March 2021

The region of the Argentine Central Andes located between 21° S and 25° S is characterized by multiple morphotectonic provinces that strongly control structural and geomorphologic surface deformation. This work focuses on the Puna Plateau and the Eastern Cordillera. The Puna is part of the orogenic Central Andean Plateau and is hydrologically dissected into internally drained catchments with mostly hyper-arid climatic conditions. The Puna’s eastern edge is bordered by the fold-and-thrust belt of the Eastern Cordillera with peaks up to ~6000 m. Both areas are repeatedly affected by earthquakes with surface deformation but seldom surface ruptures.

This research focuses on the first assessment of the L-band SAOCOM 1A data for estimating surface deformation rates. The SAOCOM 1A satellite, launched in 2018, integrates the SAOCOM mission managed by the Argentinean Space Agency (Comisión Nacional de Actividades Espaciales, CONAE). These interferometric analyses are combined with results from C-band Sentinel-1 data. Examples are shown from the surface deformation associated with the magnitude 6.3 earthquake on 30 November 2020, with an epicenter located around 70 km W of San Antonio de los Cobres village in the Southeastern portion of the Puna Plateau (~24.332° S, ~67.005° W; United States Geological Survey). Additional examples are shown for slow-moving landslide velocity estimation in the Calchaquíes range (Eastern Cordillera). Our research highlights the capabilities of the new SAOCOM satellite mission for estimating surface deformation and exploits the strength of L-band SAR in vegetated terrain.
The nature and extent of bomb tritium remaining in deep soils
Authors: Evaristo Jaivime , Huang Yanan , Li Zhi , Chun Kwok P. , Sutanudjaja Edwin H. , Bierkens Marc F.P.
Published: March 2021

Understanding the movement of water in soils is important for estimating subsurface water reserves. Despite the advances made in understanding water movement, very few tools can directly ‘follow the water’. Tritium, a tracer that decays with time and resides within individual water molecules, is one such tool. Some tritium is produced naturally, others result from the nuclear bomb test era of the 1960s. Since the atmospheric nuclear tests ended following the Partial Nuclear Test Ban Treaty in 1963, however, the amount of tritium in soil water has declined, putting into question the usefulness of the environmental tritium method for tracking water movement in future studies. Our study explores the usefulness of the tritium method. Our results highlight the narrow window of time, over the next 20 years depending on the model used, within which the tritium method may still be applicable. We call on scientists to now take full advantage of the environmental tritium method in places where the tool may still be applicable. A richer understanding of water movement in soils is ultimately critical for ecosystem services and water resources management, particularly in semi-arid environments with deep soils.
10 years of Polar Stratospheric Clouds lidar measurements at the French antarctic station Dumont d’Urville
Authors: Jumelet Julien , Tencé Florent , Sarkissian Alain , Bekki Slimane , Keckhut Philippe
Published: March 2021

Polar Stratospheric Clouds (PSCs) play a primary role in polar stratospheric ozone depletion processes. Aside from recent improvements in both spaceborne monitoring as well as investigations on microphysics and modeling, there are still caveats on building a comprehensive picture of the PSC particle population, especially considering the fine optical signatures of some particles. In that regard, groundbased instruments provide fine and long term reference measurements that complement the global spaceborne coverage.

Operated at the French antarctic station Dumont d’Urville (DDU) in the frame of the international Network for the Detection of Atmospheric Composition Change (NDACC), the Rayleigh/Mie/Raman lidar provides over the years a solid dataset to feed both process and classification studies, by monitoring cloud and aerosol occurrences in the upper troposphere and lower stratosphere. Located on antarctic shore (66°S - 140°E), the station has a privileged access to polar vortex dynamics. Measurements are weather-dependent with a yearly average of 130 nights of monitoring. Expected PSC formation temperatures are used to evaluate the whole PSC season occurrence statistics.

We hereby present a consolidated dataset from 10 years of lidar measurements using the 532nm backscatter ratio, the aerosol depolarisation and local atmospheric conditions to help in building an aerosol/cloud classification. Overall, the DDU PSC pattern is very consistent with expected typical temperature controlled thresholds. Supercooled Ternary Solution (STS) particles are the most observed particle type, closely followed by Nitric Acid Trihydrate (NAT). ICE clouds are more rarely observed. The measurements also feature significant and detailed signatures of various aerosols events having reached the polar antarctic stratosphere, like the Calbuco eruption (2015) or the 2 australian wildfires episodes (2009 and 2019). We aim at refining the identification of those aerosols to include their impact in the scope of the scientific questions studied at DDU.
Tsunami Ready in Italy: first steps
Authors: Valbonesi Cecilia , Amato Alessandro , Cugliari Lorenzo
Published: March 2021

The Italian Tsunami Alert Center of INGV (Centro Allerta Tsunami, CAT-INGV), one of the Tsunami Service Providers of NEAMTWS, has been working in the last few years for improving its warning and alerting capabilities: in recent events, initial messages have been issued between 7 and 10 minutes from the earthquakes. Other improvements of the upstream component of the TWS are being implemented. However, it is well known that the most critical part of the warning system is the so-called “last mile”, meaning the step of informing residents and tourists about the impending inundation. Therefore, a large effort is needed to fill this gap, and scientists are called to give their contribution in it. 

Among the ongoing activities to reach this objective, one of the most recent is the implementation of the Tsunami Ready (TR) Program in cooperation with Italian Civil Protection Department. TR is a virtuous model for dealing with tsunami risk, which also has numerous implications in terms of the responsibilities that can arise from a tsunami impact on the population and the environment. 

This is for at least two reasons. First, the direct involvement of citizens in the education and information process represents a significant step change because it ensures greater awareness that translates into greater citizen responsibility in tsunami risk management. In particular, the participation of citizens in the TLB (tsunami local board) requested by TR is a key element in this bottom-up risk management process.

Secondly, the adoption of internationally accredited guidelines represents a reliable parameter for determining the behavior to be adopted by public decision-makers. Therefore, when an adverse event occurs, having followed the highest available and internationally accredited standard of caution contributes to mitigating the (possible) criminal reproach against civil protection officers charged in risk management.

 

In 2020, we have started the path towards the implementation of Tsunami Ready in three municipalities in Italy, located in areas of high to moderate tsunami hazard (namely Minturno, Latium; Palmi, Calabria; Pachino/Marzamemi, Sicily). The response of local authorities has been enthusiastic in all three cases. By the end of 2020, two of them have released official resolutions launching the start of the program, followed by articles on local newspapers.

 

 
Rapidly eroding hilltops are surprisingly smooth: ridgetop curvature varies with the square root of erosion rate 
Authors: Mudd Simon M. , Gabet Emmanuel J. , Wood Ryan W. , Grieve Stuart W. D. , Binnie Steven A. , Dunai Tibor J.
Published: March 2021

The shape of soil-mantled hillslopes is typically attributed to erosion rate and the transport efficiency of the various processes that contribute to soil creep. While climate is generally hypothesized to have an important influence on soil creep rates, a lack of uniformity in the measurement of transport efficiency has been an obstacle to evaluating the controls on this important landscape parameter. We addressed this problem by compiling a data set in which the transport efficiency has been calculated using a single method, the analysis of hilltop curvatures using 1-m LiDAR data, and the erosion rates have also been determined via a single method, in-situ  ­cosmogenic 10Be concentrations. Moreover, to control for lithology, we chose sites that are only underlain by resistant bedrock. The sites span a range of erosion rates (6 – 1373 mm/kyr), annual precipitation (31 – 320 cm/yr), and aridity index (0.08 – 1.38). Surprisingly, we find that hilltop curvature varies with the square root of erosion rate, whereas previous studies predict a linear relationship. In addition, we find that the inferred transport coefficient also varies with the square root of erosion rate but is insensitive to climate. We explore various mechanisms that might link the transport coefficient to the erosion rate and conclude that present theory regarding soil-mantled hillslopes is unable to explain our results and is, therefore, incomplete. Finally, we tentatively suggest that bedrock processes may be responsible for the shape of hillslope profiles at our sites.
Exploring the near surface geothermal structure at Mt. Meager, British Columbia, Canada
Authors: Hormozzade Ghalati Fateme , Craven James A. , Motazedian Dariush , Grasby Stephen E. , Roots Eric , Tschirhart Vicki , Ansari SeyedMasoud , Liu Jon
Published: March 2021

Mount Meager is located ~150 km north of Vancouver, British Columbia Canada, and is a part of the Garibaldi volcanic belt. Exploration at Mount Meager for geothermal energy resources has been ongoing since 1974 and has shown, based on well data, that there is a permeable zone at a depth of 1200-1600 m and that the reservoir has a temperature of 270 °C near 2500 m depth. In this study, we have utilized recordings and related information from a new network of 84 audio-magnetotelluric (AMT) stations collected during the summer of 2019 plus 37 stations from previous studies to investigate the geothermal potential of the area around Mount Meager and Pylon peak. We used Phoenix Geophysics’ MTU-5C recording equipment and their proprietary software for data processing, separating extensive noise from the signal, to calculate the components of the natural electrical and magnetic signals in the frequency domain. After manual processing and editing, the data showed good quality in the frequency range of 1 to 1000 Hz. The ModEM inversion algorithm (Egbert and Kelbert, 2012) was then used to model the data. Modelling started using a coarse grid mesh with different starting resistivities, and then a finer grid size and topography was added to refine the model. The preliminary result of this 3D inversion defines the shape and location of conductors in the study area. The results show a conductor at a depth 2000 m located to the southwest of Mount Meager. Comparison of the 3D model and the geological setting of the area demonstrated that this conductor shallows toward the southern portion of the No-good Fault.
Modern pollen-vegetation-climate relationships and pollen productivity estimates for common East Siberian taxa
Authors: Geng Rongwei , Andreev Andrei , Kruse Stefan , Zhao Yan , Herzschuh Ulrike , Pestraykova Luidmila , Zakharov Evgenii
Published: March 2021

East Siberia is an ideal area for investigating the relationships between modern pollen assemblages and vegetation under the extremely cold and dry climate conditions. These relationships are the basis of paleovegetation and paleoclimate reconstructions from fossil pollen records. Pollen productivity estimates (PPE) are required for reliable pollen-based quantitative vegetation reconstructions. Here, we present a new pollen dataset of 48 moss/soil and 24 lake surface sediment samples collected from Chukotka and Yakutia. Generally, tundra and taiga vegetation sites can be well distinguished in the surface pollen assemblages from East Siberia. Moss/soil and lake samples have mostly similar pollen assemblages but contents of some pollen taxa may vary significantly in different sample types. We classified drone images based on field survey to obtain high-resolute vegetation data. Pollen counts in moss/soil samples and vegetation data can? be used in the Extended R-Value (ERV) model to estimate the relevant source area of pollen (RSAP) and the PPEs of major plant taxa. The result of PPE calculation for most common taxa (Alnus, Betula, Cyperaceae, Ericaceae, Larix, Pinus and Salix) can be used to improve vegetation reconstructions.
Lithofacies, Depositional Environment and Diagenetic Evolution of the Paleocene Patala Formation, Potwar Basin, Pakistan: Implication for Shale Gas Potential
Authors: Khan Nasar , Swennen Rudy , Weltje Gert Jan , Jan Irfan Ullah
Published: March 2021

Abstract: Reservoir assessment of unconventional reservoirs poses numerous exploration challenges. These challenges relate to their fine-grained and heterogeneous nature, which are ultimately controlled by depositional and diagenetic processes. To illustrate such constraints on shale gas reservoirs, this study focuses on lithofacies analysis, paleo-depositional and diagenetic evolution of the Paleocene Patala Formation at Potwar Basin of Pakistan. Integrated sedimentologic, petrographic, X-ray diffraction and TOC (total organic carbon) analyses showed that the formation contained mostly fine-grained carbonaceous, siliceous, calcareous and argilaceous siliciclastic-lithofacies, whereas carbonate microfacies included mudstone, wackestone and packstone. The silicious and carbonaceous lithofacies are considered a potential shale-gas system. The clastic lithofacies are dominated by detrital and calcareous assemblage including quartz, feldspar, calcite, organic matter and clay minerals with auxiliary pyrites and siderites. Fluctuations in depositional and diagenetic conditions caused  lateral and vertical variability in lithofacies. Superimposed on the depositional heterogeneity are spatially variable diagenetic modifications such as dissolution, compaction, cementation and stylolitization. The δ13C and δ15N stable isotopes elucidated that the formation has been deposited under anoxic conditions, which relatively enhanced the preservation of mixed marine and terrigenous organic matter. Overall, the Patala Formation exemplifies deposition in a shallow marine (shelfal) environment with episodic anoxic conditions.

Keywords: Lithofacies, Organic Matter, Paleocene, Potwar Basin, Shale Gas, Shallow Marine.
Spatial and temporal variation of 13C-signature of methane emitted by a temperate mire ecosystem
Authors: Rinne Janne , Łakomiec Patryk , Vestin Patrik , Weslien Per , Kelly Julia , Liljebladh Bengt , Xie Xianghua , Kljun Natascha , Ström Lena , Klemedtsson Leif
Published: March 2021

The net methane emission of any mire ecosystem results from a combination of biological and physical processes, including methane production by archaea, methane consumption by bacteria, and transport of methane from peat to the atmosphere. The complexity of spatial and temporal behavior of methane emission is connected to these.

13C-signature of emitted methane offers us a further constraint to evaluate our hypothesis on the processes leading to the variation of methane emission rates. For example, assuming the spatial variation in methane emission rate at microtopographic scale is due to variation in trophic status or variation in methane consumption, will lead to differences in the relation of methane emission rate and its 13C-signature, expressed as δ13C.

We have measured the methane emission rates and δ13C of emitted methane by six automated chambers at a poor fen ecosystem over two growing seasons. The measurements were conducted at Mycklemossen mire (58°21'N 12°10'E, 80m a.s.l.), Sweden, during 2019-2020. In addition, we measured atmospheric surface layer methane mixing ratios and δ13C to obtain larger scale 13C-signatures by the nocturnal boundary-layer accumulation (NBL) approach. All δ13C-signatures were derived using the Keeling-plot approach.

The collected data shows spatial differences of up to 10-15 ‰ in 10-day averages of δ13C-signatures between different chamber locations. Temporal variations of 10-day average δ13C-signatures from most chamber locations reached over 5 ‰, while the temporal variation of NBL derived δ13C-signature was slightly lower.

The observed spatial variation in the δ13C-signature was somewhat systematic, indicating, especially in the middle of the summers, the main control of spatial variation of methane emission to be the trophic status. The temporal changes, measured at different locations, indicate spatial differences in the temporal dynamics at the microtopographic scale. The temporal behavior of larger scale NBL δ13C-signature does not fully correspond to the behavior of the chamber derived average δ13C-signature.
Evaluation of soil carbon dynamics after land use change in CMIP6 land models using chronosequences
Authors: Brovkin Victor , Boysen Lena , Wårlind David , Peano Daniele , Lansø Anne Sofie , Delire Christine , Burke Eleanor , Poeplau Christopher , Don Axel
Published: March 2021

Land surface models are used to provide global estimates of soil organic carbon (SOC) changes after past and future land use change (LUC). To evaluate how well the models capture decadal scale changes in SOC after LUC, we provide the first consistent comparison of simulated time series of LUC by six land models all of which participated in the Coupled Model Intercomparison Project Phase 6 (CMIP6) with soil carbon chronosequences (SCC). For this comparison we use SOC measurements of adjacent plots at four high-quality data sites in temperate and tropical regions. We find that initial SOC stocks differ among models due to different approaches to represent SOC. Models generally meet the direction of SOC change after reforestation of cropland but the amplitude and rate of changes vary strongly among them. Further, models simulate SOC losses after deforestation for crop or grassland too slow due to the lack of crop harvest impacts in the models or an overestimation of the SOC recovery on grassland. The representation of management, especially nitrogen levels is important to capture drops in SOC after land abandonment for forest regrowth. Crop harvest and fire management are important to match SOC dynamics but more difficult to quantify as SCC hardly report on these events. Based on our findings, we identify strengths and propose potential improvements of the applied models in simulating SOC changes after LUC.
Diffraction imaging and depth-velocity inversion with 3D P-Cable seismic data
Authors: Bauer Alexander , Schwarz Benjamin , Gajewski Dirk
Published: March 2021

Most established methods for the estimation of subsurface velocity models rely on the measurements of reflected or diving waves and therefore require data with sufficiently large source-receiver offsets. For seismic data that lacks these offsets, such as vintage data, low-fold academic data or near zero-offset P-Cable data, these methods fail. Building on recent studies, we apply a workflow that exploits the diffracted wavefield for depth-velocity-model building. This workflow consists of three principal steps: (1) revealing the diffracted wavefield by modeling and adaptively subtracting reflections from the raw data, (2) characterizing the diffractions with physically meaningful wavefront attributes, (3) estimating depth-velocity models with wavefront tomography. We propose a hybrid 2D/3D approach, in which we apply the well-established and automated 2D workflow to numerous inlines of a high-resolution 3D P-Cable dataset acquired near Ritter Island, a small volcanic island located north-east of New Guinea known for a catastrophic flank collapse in 1888. We use the obtained set of parallel 2D velocity models to interpolate a 3D velocity model for the whole data cube, thus overcoming possible issues such as varying data quality in inline and crossline direction and the high computational cost of 3D data analysis. Even though the 2D workflow may suffer from out-of-plane effects, we obtain a smooth 3D velocity model that is consistent with the data.
Geochronological and paleomagnetic studies of small carbonatite intrusions of the Udzha uplift (Tomtor massif, northeast of the Siberian platform)
Authors: Pasenko Aleksandr , Alexey Ivanov , Sergey Malyshev , Alexey Travin
Published: March 2021

Paleomagnetic data obtained from Neoproterozoic glacial and glacier-associated sedimentary rocks indicate that they were formed at near equatorial latitudes. Based on these data, the Snowball Earth hypothesis was proposed [Kirschvink, 1992]. According to this hypothesis, during the Neoproterozoic glaciations, the entire planet (including the oceans) was completely covered with ice. Although evidence is emerging that does not support this hypothesis, there is still no conclusive evidence that it is not true [Sansjofre et al., 2011].

It is worth noting that the Snowball earth hypothesis is based on paleomagnetic data. At the same time, the available paleomagnetic data for the Neoproterozoic-Early Cambrian [Meert, Van der Voo, 2001; Shatsillo et al, 2005; Abrajevitch, Van der Voo, 2010; Pavlov et al., 2018] difficult to interpret in terms of the Geocentric Axial Dipole hypothesis. This imposes serious restrictions on the possibility of correctly constructing paleomagnetic reconstructions.

For the development and testing of a model of the geomagnetic field of the Neoproterozoic, it is necessary to obtain a lot of high-quality paleomagnetic data. Data from well-dated magmatic bodies are especially valuable.

Within the framework of this work, we obtained paleomagnetic data from three carbonatite dikes (7 to 30 cm thickness) exposed in the Udzha river bank on the Udzha uplift in the northeastern part of the Siberian platform. These dikes are associated with the large alkaline Tomtor massif located 15 km to the west. Ar/Ar dating of phlogopite megacrysts gives an intrusion age of the dikes of 706.1±8.8 Ma. Coordinates of the virtual geomagnetic pole, calculated from the direction of the high-temperature component of magnetization: Φ=-20.7°; Λ=88.6°; Α95=3.4°.

Our report will present preliminary interpretation of these data, as well as their comparison with paleomagnetic data on close-aged objects in Siberia.

The research was supported by the Russian Science Foundation grant (19-77-10048).

References:
Dendrogeomorphic reconstruction of debris-flow activity in Mazeri Valley, Greater Caucasus, Georgia
Authors: Pop Olimpiu , Germain Daniel , Gavrilǎ Ionela-Georgiana , Elizbarashvili Mariam
Published: March 2021

The Mazeri Valley in the Greater Caucasus (Georgia) is characterized by a highly dynamic landscape with several active mass-wasting processes. The spatial and temporal dynamics of these geomorphic processes have, over time, resulted in the formation of large cones and fans. In this context, the coupling between the hillslope and the channel plays a fundamental role in controlling the catchment sediment dynamics. The sediment produced at higher altitudes on hillslopes may occasionally reach the debris-flow channel network, and downstream propagation may have significant effects on the fluvial environment and create potential hazards for the resident population, tourists and infrastructures. In this study, we aim to better understand sediment fluxes in the mountain headwater stream in the Mazeri Valley. In this regard, a tree-ring-based chronology of the debris-flow activity on a large cone was created, to shed light on sediment connectivity and better understand the coupling between the main debris-flow channel and the bedload of Dolra river. The 161 disturbed trees sampled allowed to reconstruct a minimum of 12 significant debris-flow events over the last 65 years, with all of these events involving possible sediment input into the stream system of the Dolra river. These successional events, with a return interval of 5.4 years, have partially destabilized the fluvial system and locally induced a switch in the channel style to a braided channel. Although the cone studied is not directly located in a proglacial environment, its geomorphological dynamics remain highly dependent on water and sediment inputs from upstream, giving the presence of retreating glaciers and then paraglacial conditions at high altitude. The ongoing glacial retreat and increased climate variability will certainly lead to a massive output of sediments at high altitude, favoring an increase in geomorphic activity in the area. Many other fan and cone complexes are present in the Mazeri Valley, as well as in other adjacent valleys, and there are no documentations regarding their dynamics (e.g., typology, nature and source areas of hillslope processes, their coupling with channelized sediment-water flows, frequency–magnitude relationships). In this regard, we expect that the present pioneering study in this area will encourage more researches to investigate sediment fluxes for a better land use and preservation of water in Georgia under climate change.

Cette étude représente une contribution pour le projet « Impact du changement climatique sur les glaciers et les risques associés dans le Caucase Géorgien - IMPCLIM », financé par l’Agence Universitaire de la Francophonie (AUF) et le Ministère pour la Recherche et l'Innovation de Roumanie (MRI) à travers l'Institut Roumain de Physique Atomique (IFA).
In situ observations of the near-shore atmospheric boundary layer during ATOMIC/EUREC4A from small Uncrewed Aircraft Systems  
Authors: de Boer Gijs , Calmer Radiance , Borenstein Steven , Choate Christopher , Rhodes Michael , Hamilton Jonathan , Cox Christopher , Argrow Brian , Intrieri Janet
Published: March 2021

During the 2020 Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign (ATOMIC) and ElUcidating the Role of Cloud- Circulation Coupling in ClimAte (EUREC4A) field campaigns, a team from the University of Colorado Boulder deployed the RAAVEN Remotely-Piloted Aircraft System (RPAS). The RAAVEN RPAS was equipped with the miniFlux measurement system to observe the marine boundary layer upwind of Morgan Lewis, Barbados.  Over the course of 23 days, the team completed 39 flights covering nearly 80 flight hours.  Flights were conducted in and just above the boundary layer at altitudes between 10 and 1000 m, with a focus on capturing regular thermodynamic and kinematic profiles of the lower atmosphere, along with statistics on vertical transport and spatial variability.  In this presentation, we will give initial details on the observed state of the lower atmosphere.  This includes information on the structure and internal variability of thermodynamic and kinematic properties, turbulence intensity, turbulent surface fluxes and their variability, and details on the structure of vertical velocities in the lower atmosphere.
Production and calcification variations of the key coccolithophore species Gephyrocapsa during the Late Pleistocene (MIS 14 to MIS 7)
Authors: González-Lanchas Alba , Flores José-Abel , Sierro Francisco J.
Published: March 2021

There is an increasing interest in understanding the role of coccolithophores, a group of major calcifying phytoplankton, in the marine carbon cycle: they have a dual contribution to the operation of the carbonate and biological pumps during their lifecycle. How the recent changes in seawater carbonate chemistry are affecting their production and calcification is a matter of debate in the scientific community. Culture experiments suggest that modern coccolithophore species (Emiliania huxleyi) is sensitive to such variations. Conversely, could past evolutionary or adaptative changes in the most important coccolithophore species have an impact on ocean chemistry?  

We focus on the interval comprising the MIS 14 to 7 (Mid-Brunhes, Pleistocene) when a remarkable increase in the amplitude of glacial/interglacial atmospheric CO2 was recorded. We analyzed (i) the composition of the dominant coccolithophore Gephyrocapsa assemblages and (ii) the morphometric parameters (length, mass, and thickness) of its coccoliths (carbonated scales) in samples from a set of sediment cores (Sites IODP U1314, U1385and ODP 925 and 977) located in a north-south transect in the North Atlantic and the western Mediterranean Sea. We estimated the primary productivity conditions at the different regions and explore methodological approaches to measure the calcification of Gephyrocapsa coccoliths.

Preliminary results show a correlation between the abundance of coccoliths, assemblage composition, and coccolith morphology at different regions. A comparison with geochemical and sedimentological records suggests a significant role of Gephyrocapsa coccolithophore in marine organic and carbonate production throughout the interval. These observations open the discussion about the existence of a global environmental relationship between coccolithophore assemblages and coccolith morphometrical variations, but also, a possible impact of the changes in the Gephyrocapsa production and calcification on the ocean chemistry.
Up to date geodetic velocity field of the Belledonne region (Western Alps, France)
Authors: Hannouz Estelle , Walpersdorf Andrea , Sue Christian , Mathey Marguerite , Baize Stéphane , Lemoine Anne
Published: March 2021

       The Belledonne region, located on the western edge of the French Alps, behaves as a deformation transfer zone between the inner part of the western Alps, where geodesy and seismicity show extensional deformation, and its compressional surrounding basin (the Rhône Valley). Seismological and geodetic networks are less dense and younger in the Rhône Valley, which makes it more difficult to characterize its deformation. Nevertheless, these two regions have a moderate historical and instrumental seismicity. A large part of these earthquakes is concentrated on the Belledonne range and accommodated by the active NE–SW Belledonne fault, located at the western foot of this chain. The fault characteristics, such as its connection at depth with surrounding fault systems (e.g. Cléry fault), still need better constraints. The dense seismological network present in the Alpine region has made it possible to highlight its dextral strike-slip kinematics. To complete these observations, we present here an update of the geodetic velocity field around this fault from GNSS data recorded over the last two decades.

To do so, we first computed daily positions for a total of about 200 stations provided by different European networks (IGS, RENAG, RGP, GAIN, DGFI networks) over a period of 23 years (from 1997 to 2020), by using a double-difference processing with the GAMIT software (Herring et al. 2015). Then, we constrained a velocity field with the Kalman filter GLOBK with respect to the fixed European plate. We finally analyzed the residual motions in our area of interest with respect to stable Europe, as provided by our updated velocity field.

Across the Belledonne range, our results show a deformation pattern consistent with the dextral strike-slip mechanism observed by the current seismicity. Methodological studies concern the expected decrease of uncertainty on the velocity field thanks to the increase of recordings through time. These tests aim at quantifying the Belledonne fault present-day slip rate, including a well-constrained velocity uncertainty. We also exploit the new 3D velocity field to confirm and precise the local amplitude, in the Belledonne area, of the general uplift of the Alpine belt, as observed by previous geodetic studies.
Constraining the absorbing fraction of organic aerosol in an atmospheric chemistry model
Authors: Navarro-Barboza Hector , Obiso Vincenzo , Sousse Rubén , Pandolfi Marco , Pérez García-Pando Carlos , Jorba Oriol
Published: March 2021

Atmospheric aerosols have a significant influence on the climate system. On average, aerosols cool the atmosphere directly by scattering solar radiation and indirectly through aerosol–cloud interactions. However, some aerosol components are capable of absorbing visible solar radiation and warming the lower atmosphere. The most prevalent types of absorbing aerosols are black carbon (BC) and mineral dust. Most organic aerosols (OA) can be characterized as "white" because they efficiently scatter visible radiation. Recently, analyses from laboratory and field experiments have provided strong evidence for the existence of some OA with light absorbing properties. In recent scientific literature, the term "brown carbon" (BrC) has emerged to describe this type of OA, characterized by an absorption spectrum that smoothly increases from visible to UV wavelengths. Main sources of primary BrC are biomass burning and residential coal combustion, but recent studies have postulated the existence of various secondary sources of BrC resulting from multi-phase reactions of volatile organic compunds exposed to nitrogen oxides and ammonia.

In this work, we combine different evaluation strategies to constrain the absoprtion of organic aerosols simulated by the Multiscale Online Nonhydrostatic Atmosphere Chemistry (MONARCH) model. The validation of the model focuses mostly on the concentrations and optical properties of BC, OA and BrC. In-situ surface measurements of PM chemical composition (both off-line and on-line) and optical properties (multi-wavelengths scattering and absorption) provided by IDAEA-CSIC and columnar integrated optical properties (optical depth, single scattering albedo and asymmetry factor) derived from the Aerosol Robotic Network (AERONET) are used. We discuss different sensitivity runs at the regional and global scale perturbing (i) the OA/BrC fraction of biomass burning and biofuel emissions, (ii) the refractive index of OA and BrC aerosol components, and (iii) the aging rates of photobleaching and browning processes.
Wildfire ash mobilization by splash under simulated rainfall in controlled laboratory conditions
Authors: Martins Ricardo , Keizer Jacob , Abrantes João R.C.B. , González-Pelayo Oscar , de Lima Isabel Pedroso , de Lima João Luis M. Pedroso
Published: March 2021

Recently burnt areas across the world have been documented to produce strong to extreme runoff and erosion responses. At the same time, they are well known to lose their typically blackish colour due to wildfire ashes (sensu latu, including char) relatively quickly during the early phases of the window-of-disturbance. The contribution of wildfire ash to post-fire erosion rates, however, remains poorly quantified. Arguably, this is first and foremost due to the difficulties of separating the ash and char fractions from the mineral soil fractions, at least at the routinely basis that is required for field erosion studies with high temporal resolution (say, less than 1 month) and an absolute minimum of three replicate plots per slope or treatment. To this end, the national ASHMOB project (CENTRO-01-0145-FEDER-029351) is trying to advance the knowledge of the mobilization of wildfire ash by wind and water erosion by studying it first under controlled laboratory conditions. The present study concerns the first phase of wildfire ash erosion by water, using Morgan cups to quantify the splash erosion of wildfire ash by high-intensity simulated rainfall in the Laboratory of Hydraulics, Water Resources and Environment of the University of Coimbra. More specifically, this study assessed the importance of the following factors in ash splash erosion: (1) extreme rainfall intensities, ranging from 150 to 450 mm/h; (2) source of the ash, from recently burnt woodlands dominated by maritime Pinus pinaster, Eucalyptus globulus, and Arbutus unedo; (3) ash depth or load. Preliminary analysis of the obtained results suggested that splash erosion of wildfire ash: (1) varied strongly with the applied rainfall intensity, increasing in a linear manner with increasing intensity; (2) differed markedly with the dominant tree cover, being clearly lower for the pine and eucalypt stands than for the strawberry tree stands, possibly due to the differences in soil burn severity as indicated by blackish and whitish ashes, respectively; (3) depended noticeably on ash depth, decreasing clearly with increasing ash depth and, arguably, with a greater damping capacity.
A deep learning approach for efficient multi-temporal interferometric synthetic aperture radar (MT-InSAR) processing
Authors: Tiwari Ashutosh , Narayan Avadh BIhari , Dikshit Onkar
Published: March 2021

Multi-temporal interferometric synthetic aperture radar (MT-InSAR) technique has been effectively used to monitor deformation events over the last two decades. The processing steps generally involve pixel selection, phase unwrapping and displacement estimation. The pixel selection step takes most of the processing time, while a reliable method for phase unwrapping is still not available. This study demonstrates the effect of using deep learning (DL) architectures for MT-InSAR processing. The architectures are applied to reduce time computations and further to improve the quality of pixel selection. Some promising results for pixel selection have been shown earlier with the proposed architecture. In this study, we investigate the performance of the proposed architectures on newer datasets with larger temporal interval. To achieve this objective, the models are retrained with interferometric stacks covering larger temporal period and large time steps (for better estimation of interferometric phase components). Pixel selection results are compared with those obtained using open access algorithms used for MT-InSAR processing.
Geostatistical approach for multi-scale seismic liquefaction risk assessment
Authors: Spacagna Rose Line , Cesarano Massimo , Fabozzi Stefania , Peronace Edoardo , Porchia Attilio , Romagnoli Gino , Moscatelli Massimiliano
Published: March 2021

The Seismic Microzonation studies (SMs), promoted all over the Italian territory by the Department of Civil Protection, provide fundamental knowledge of the subsoil response in seismic conditions at the urban scale. Amplification phenomena related to lithostratigraphic and morphological characteristics, instabilities and permanent deformations activated by the earthquake, are highlighted in hazard maps produced at increasing reliability levels (level 1 to 3 of SM). In particular, zones prone to liquefaction instability are firstly identified following the predisposing factors, such as geological and geotechnical characteristics and seismicity. The robustness of the definition of these areas is strongly correlated to the availability and the spatial distribution of surveys. Moreover, the typology and quality of the investigations considerably influence the method of analysis and the degree of uncertainty of the results.

This work aims to establish an updated procedure of the actual SM guidelines and integrates recent research activities at different levels of SMs, to improve the hazard maps accuracy in terms of liquefaction susceptibility. For the scope, the case of the Calabria region in the south of Italy, well known for the high level of seismicity, was studied. At a regional scale, the base-level analysis was implemented for a preliminary assessment of the Attention Zones (AZ), potentially susceptible to liquefaction. The predisposing factors were implemented at a large scale, taking advantage of geostatistical tools to quantify uncertainties and filter inconsistent data. The regional-scale analysis allowed to highlight areas prone to liquefaction and effectively addressed the subsequent level of analysis. At a local scale, the quantitative evaluation of the liquefaction potential was assessed using simplified methods, integrating data from different survey types (CPT, SPT, Down-Hole, Cross-Hole, MASW) available in SM database. The definition of Susceptibility Zones (SZ) was provided considering additional indexes, combining the results obtained from different surveys typologies and quantifying the uncertainty due to the limited data availability with geostatistical methods. The analyses at the regional and municipality scale were matched with seismic liquefaction evidence, well documented in past seismic events. This multi-scale process optimises resource allocation to reduce the level of uncertainty for subsequent levels of analysis, providing useful information for land management and emergency planning.