bluuebunny/crossref_metadata_2025 huggingface dataset:
Insights into GHG emissions from faulty oil and gas wells in the Western Canada Sedimentary Basin
Authors: Gonzalez Arismendi Gabriela , Muehlenbachs Karlis
Published: March 2022

Understanding the source of fugitive methane is key to any mitigation effort. Unwanted emissions from oil and gas wells are significant contributors to greenhouse gas (GHG) emission budgets in petroliferous regions. Here we examine in detail, parameters that may be controlling GHG emission rate of individual, faulty wells in the Western Canada Sedimentary Basin (WCSB). For several hundred wells, we compared the source depth of the leaks determined by isotope fingerprinting to publicly available surface casing vent shut-in pressures and gas emission flow rates in three different oil and gas fields of WCSB. About seventy-five percent of the leaks are from shallower and intermediate formations rather than the targeted formations in most areas. The depth of leaks does not vary between horizontal and vertical wells in a given region. The source depth of the leaking gas is not correlated with the age of the well. Most of the leaks in a region come from specific gas-charged intermediate formations. We observe that smaller leaks come from both the shallower intermediate and the target zones. Surprisingly, the higher shut-in pressure and larger surface casing flows tend to come from shallower depths.  In these cases, it was observed that the drillers had used comparatively less cement. There are many thousands of faulty wells in the WCSB, and our observations can guide the prioritization of remediation to most quickly and economically reduce GHG emissions.
Human land-use increases earthworm diversity at local scale but not at the regional scale while improves abundance, biomass, and body size
Authors: Wang Dingyi , Li Xianping , Du Yan , Sun Jing , Qi Xiaoxu , Xu Maogang , Jiao Kuihu , Zhang Yu , Zhang Chongzhe , Shi Sibo , Gong Xin , Wu Di , Liu Manqiang
Published: March 2022

Global biodiversity is being threatened by climate change and human activities. Prior studies have demonstrated the negative concequences of land-use such as conversion of forest into monoculture, while its effects on belowground organisms especially soil invertebrates remain unclear. Earthworms are well-known ecosystem engineers that deliver multiple ecosystem functions including decomposition, carbon sequestration and plant growth. Yet, all of those functions are negatively affected by land-use conversion. Previous studies concerning land-use effects on soil biodiversity were generally conducted at a single site and small spatial scale, how soil biodiversity changes across spatial scales remains poorly understood.

In current study, earthworms were quantitatively sampled from 41 sites in three land-use types (i.e., farmland, orchard and forest at each site, five replicates) in subtropical region of China. Earthworm species were identified using both morphological and molecular methods. Earthworm density, biomass and body size were recorded. Notably, the species were also classified into different functional guilds. Totally, 84 species (or subspecies) were identified. Generally, local diversity (α diversity) was higher in agricultural lands than in forest lands, however, the opposite was true for regional diversity (γ diversity). In addition, the density of earthworm was the lowest in forest, while the biomass and body size were higher in agricultural lands. A higher proportion of endogeic and anecic earthworms were found in farmland and orchard than in forest. The land-use caused changes in soil properties contributed to the difference in earthworm diversity, abundance, biomass and body size.

In conclusion, we suggest that the impacts of human land-use on soil earthworm assemblage are scale-dependent, and the diversity, abundance, biomass and body size respond differently to land-use. Researches on different scales about land-use effects to soil biodiversity are urgently needed.
Impact of Stratospheric Ozone on the Subseasonal Prediction in the Southern Hemisphere Spring
Authors: Oh Jiyoung , Son Seok-Woo , Choi Jung , Lim Eun-Pa , Carfinkel Chaim , Hendon Harry , Kim Yoonjae , Kang Hyun-Suk
Published: March 2022

Antarctic ozone has been regarded as a major driver of the Southern Hemisphere (SH) circulation change in the recent past. Here, we show that Antarctic ozone can also affect the subseasonal-to-seasonal (S2S) prediction during the SH spring. Its impact is quantified by conducting two reforecast experiments with the Global Seasonal Forecasting System 5 (GloSea5). Both reforecasts are initialized on September 1st of each year from 2004 to 2020 but with different stratospheric ozone: one with climatological ozone and the other with year to-year varying ozone. The reforecast with climatological ozone, which is common in the operational S2S prediction, shows the skill re-emergence in October after a couple of weeks of no prediction skill in the troposphere. This skill re-emergence, mostly due to the stratosphere-troposphere dynamical coupling, becomes stronger in the reforecast with year to-year varying ozone. The surface prediction skill also increases over Australia. This result  suggests that a more realistic stratospheric ozone could lead to improved S2S prediction in  the SH spring.
Juno Probes the Dynamo Region and Detects Secular Variation of the Magnetic Field
Authors: Connerney Jack
Published: March 2022

A spherical harmonic model of the magnetic field of Jupiter is obtained from vector magneticfield observations acquired by the Juno spacecraft during 32 of its first 33 polar orbits. These Prime Mission orbits sample Jupiter's magnetic field nearly uniformly in longitude (~11° separation) as measured at equator crossing. The planetary magnetic field is represented with a degree 30 spherical harmonic and the external field is approximated near the origin with a simple external spherical harmonic of degree 1. Partial solution of the underdetermined inverse problem using generalized inverse techniques yields a model (“JRM33”) of the planetary magnetic field with spherical harmonic coefficients reasonably well determined through degree and order 13. Useful information regarding the field extends through degree 18, well fit by a Lowes' spectrum with a dynamo core radius of 0.807 +/- 0.006 Rj, presumably the outer radius of the convective metallic hydrogen region that exists beneath a layer stably stratified by precipitation of “helium rain”. This new model provides a most detailed view of a planetary dynamo and evidence of advection of the magnetic field by deep zonal winds in the vicinity of the Great Blue Spot (GBS), an isolated and intense patch of flux near Jupiter's equator. Comparison of the JRM33 and JRM09 models suggests secular variation of the field in the vicinity of the GBS during Juno's nearly 5 years of operation in orbit about Jupiter. The observed secular variation is consistent with the penetration of zonal winds to a depth of ~3,500 km where a flow velocity of ~0.04 ms−1 is required to match the observations. At this rate the GBS circles the planet in about 350 years.
Analysis of Saint-Petersburg`s CO2 anthropogenic emissions estimation by differential spectroscopy method
Authors: Timofeyev Yury , Nerobelov Georgy , Poberovskiy Anatoliy
Published: March 2022

Needs in obtaining independent and high-quality information on anthropogenic emissions of important for climate and ecology gases led to the development of spectroscopic (ground-based and satellite) methods of the emission determination. This challenge can be reduced to two sequential inverse problems - the inverse problem of atmospheric optics and atmospheric transport. Here we studied the merits and disadvantages of differential IR methods for the emissions estimation. Also we investigated the main factors determining their errors such as:

Quality and number of the observations of spatio-temporal distribution of gases studied

Capabilities of the numerical models to simulate atmospheric transport

Spatial and temporal resolutions of emissions estimated

etc.

In the current study integral anthropogenic CO2 emissions of Saint-Petersburg were determined using observation data of the city`s anthropogenic contribution to the gas content. In addition we implemented a new approach of inverse problem solution which was based on a priori CO2 emission data and scale coefficients applied only to the city`s areas covered by the observations. Integral anthropogenic CO2 emissions obtained were in a range from approximately 52 to 72 Mt/year. These emissions are significantly higher than inventory-based estimates which constitute ⁓30 Mt/year. Nevertheless, the minimal value of the range (~52 Mt/year) is lower by ~21% than emissions which we calculated earlier also using observations (~65 Mt/year).
An application of evapotranspiration partitioning for monitoring drought from Sentinel-2 data
Authors: Nguyen My , Jeon Hyunho , Kim Wanyub , Choi Minha
Published: March 2022

Drought is one of the globally extreme events and is physically defined as an extended imbalance between moisture supply and demand, which might severely affect crop growth and water preservation. More specifically, agricultural and meteorological droughts are manifest as the deficits in actual evapotranspiration (ET) and a surplus in atmospheric evaporative demand ET0 (sometimes referred to as potential ET). Therefore, the accurate estimations and reliable information regarding to ET might enhance the drought monitoring and provide better agricultural management policies. However, ET estimations and its components remain many challenges. For example, as three ET contributors are soil evaporation (ETsoil), plant transpiration (ETveg), and vegetation interception evaporation (ETic), current ET models tend to ignore the ETic and consider it as residual of two others. This leads to the uncertainties and incomprehensive reflection of ET. Additionally, ET models-based flux measurement might produce good accurate results, but they have limitations of spatial coverage. With the rapid development of remote sensing platforms, the models-based remote sensing are able to cover a large and regional scale, but they remain higher uncertainties due to the low spatial resolution, complexities in processing, requirements of many input data. Currently, the optical Sentinel-2 is a newly launched product with the Multi Spectral Instruments that might provide 10, 20, and 60-m spatial resolution, which potentially supports to design and improve ET models with superior performance. To overcome these mentioned disadvantages of ET models, the main objective of this study are to propose a simple and objective method using only optical Sentinel-2 dataset to improve the accuracy of ET estimation; and to project the enhanced ET partitioning as feasible method for further monitoring the agricultural drought. This study might bridge the gap in knowledge and applicability of ET in monitoring the hydrological disasters under severe climate change context.
An integrated GIS-based pumping-injection control system developed for preventing the spread of NAPL contaminants in a groundwater system 
Authors: Lee Seong-Sun , Park Inwoo , Lee Suh-Ho , Jun Seong-chun , Lee Kang-Kun
Published: March 2022

The objectives of this study are to develop an integrated GIS-based pumping-injection operation system that can hydraulically control the spread of groundwater contaminants and contaminant plumes and to suggest the optimized operation condition that can prevent the spreading of contaminant plume with a hydraulic flow control concept in a short period. Since there are no cases of simultaneously implementing the numerical modeling for groundwater flow and contaminant transport in groundwater monitoring or management systems at contaminated sites, the system developed through this project is an integrated operation system that can implement the numerical modeling of both groundwater flow and contaminant transport on the web and can suggest optimal remediation factors using Simulation-Optimization method. Among various studies associated with groundwater remediation at NAPL contaminated sites, this study performs to suggest cost-effective remediation factors using a simulation-optimization model that takes into account the hydrogeological factors of the contaminated site when performing remedial action by the pumping-injection method. The Genetic Algorithm(GA) code was used for the development of the optimal remediation design algorithm for the pumping-injection system. The developed optimization algorithm was verified through the simplified numerical model simulation considering random contaminant sources. And then this algorithm was applied to actual DNAPL contaminated site. The developed integrated operating system was able to smoothly perform the model for groundwater flow and contaminant transport on the web. In addition, the optimization model related to remedial action operation was well linked to the web operating system to derive optimal operating factors. This work was supported by Korea Environment Industry &Technology Institute (KEITI) through "Activation of remediation technologies by application of multiple tracing techniques for remediation of groundwater in fractured rocks"(Grantnumber:20210024800002/1485017890), "Hydraulic control and containment using pumping-injection system" (SEM projects 2020002470001/1485017133) by the Korea Ministry of Environment(MOE)" and Korea Environment Industry & Technology Institute(KEITI) through the Demand Responsive Water Supply Service Program (RE20191097) funded by the Korea Ministry of Environment (MOE).

 
Evaluating Visitor’s Expectations and Interests in the realm of Earth Sciences – Results From an Online Survey
Authors: Seybold Lina , Schneider Simon , Junge Malte , Kaliwoda Melanie , Simon Gilla , Koelbl-Ebert Martina , Baumann Annekathrin
Published: March 2022

A new campus for geosciences will be built in the center of Munich, which will also house an innovative exhibition on geosciences, the Forum der Geowissenschaften. A team of scientists, curators and museum educators began planning the exhibition last year.

Topics from all sub-fields of geoscience and geoscientific research are to be presented in an exciting and informative way for a broad spectrum of visitors. A catalogue of topics and content for the forthcoming permanent exhibition is currently in preparation. Since the topics that the team of experts find most interesting do not always coincide with the interests of the general public, potential visitors should be involved in the planning process, too. For this purpose, an online survey was conducted. The aim of this survey was to obtain an overview of geo-topics that would be considered particularly exciting and relevant by the future public. The survey should reveal which topics visitors would like to see in the future Forum der Geowissenschaften and which information they expect to find in the exhibition.

Existing email distribution lists of museums in Munich, the Bavarian Natural History Collections, the university and other partner institutions were used to call for participation in the survey. The distribution lists used suggest that this survey targeted a field of participants that included the so-called ‘interested layperson’, teachers, and people directly related to geological research.

Participants were asked to rate a wide range of topics according to their interest on a Likert scale from ‘very interested’ to ‘not interested’. In addition, open questions asked participants to name other topics they found interesting.

More than 750 evaluable responses were received. First results, which are presented here, indicate very heterogeneous interests of the different age groups and professions. In addition, the interest in the different topics can be interpreted in relation to the self-assessed prior knowledge in geosciences but also in relation to demographic data such as gender and place of residence.

All in all, the survey provides a comprehensive database that will help to refine the exhibition concept and to design further communication measures. However, the data also stimulates a discussion about whether topics are considered by participants to be of little interest because these topics may have been communicated inadequately and ineffectively to date. If this is the case, the    geosciences need to find new, modern approaches to science communication in order to arouse curiosity about these topics, which are often of great social relevance.
Coupling of lightning generated electromagnetic waves to the inner magnetosphere: a case study
Authors: Santolík Ondřej , Kolmašová Ivana , Pickett Jolene S. , Gurnett Donald A.
Published: March 2022

Our case study aims at contributing to the discussion on sources of plasmaspheric hiss, which is known for its interactions with the Earth radiation belts. We analyze multi-point measurements of electromagnetic field waves by the Wide Band Data instruments onboard the four Cluster spacecraft in order to find sources of hiss observed close to the geomagnetic equator in the dayside outer plasmasphere. We find hiss to be triggered from whistlers of different spectral properties. Whistlers with the lowest observed dispersion arrive to different spacecraft with time delays indicating their origin in the northern hemisphere. Positions of source lightning discharges are then found using the time coincidences with the Word Wide Lightning Location Network data from three active thunderstorm regions in Europe. We find that subionospheric propagation of lightning atmospherics is necessary to explain the observations. Geographic locations of their ionospheric exit points then determine spectral properties of resulting unducted whistlers and triggered hiss. By this well documented chain of events starting with a lightning discharge in the atmosphere we confirm that magnetospherically reflecting whistlers and hiss triggered from them are among possible sources of plasmaspheric hiss.
openEO Platform: Enabling analysis of large-scale Earth Observation data repositories with federated computational infrastructure 
Authors: Schumacher Benjamin , Griffiths Patrick , Pebesma Edzer , Dries Jeroen , Jacob Alexander , Thiex Daniel , Mohr Matthias , Briese Christian
Published: March 2022

The growing data stream from Earth Observation (EO) satellites has advanced scientific knowledge about the environmental status of planet earth and has enabled detailed environmental monitoring services. The openEO API developed in the Horizon 2020 project openEO (2017–2020, see https://openeo.org/) demonstrated that large-scale EO data processing needs can be expressed as a common set of analytic operators which are implemented in many GIS software or image analysis software products. The openEO Platform service implements the API into an operational, federated service currently running at back-ends at EODC and VITO with access to SentinelHub data to meet processing needs of a wide user community.

openEO Platform (https://openeo.cloud/) enables users to access a large collection of open EO data and perform scientific computations with intuitive client libraries simplifying underlying complexity. The platform is currently under construction with a strong focus on user co-creation and input from various disciplines incorporating a range of use-cases and a free-of-charge Early Adopter program that allows users to test the platform and to directly communicate with its developers. The use cases include CARD4L compliant ARD data creation with user defined parameterisation, forest dynamics mapping including time series fitting and prediction functionalities, crop type mapping including EO feature engineering supporting machine learning based crop mapping and forest canopy mapping supporting regression based fraction cover mapping.

The interaction with the platform includes multiple programming interfaces (R, Python, JavaScript) and a browser-based management console and model builder which allows a direct, interactive display and modification of processing workflows. The resulting processing graph is then forwarded via the openEO API to the federated back-ends.

In the future users will be able to process continental-scale EO data and create ready-to-use environmental monitoring services with analysis-ready data (ARD) and predefined available processes. This presentation will provide an overview of the current capabilities and the evolution roadmap of openEO Platform. It will demonstrate the utility of the platform to process large amounts of EO data into meaningful information products, supporting environmental monitoring, scientific research and political decision-makers.
Modelling Pore Size Distribution, Water Retention and Hydraulic Conductivity of Granular substrates using a Universal Multifractal-based approach for Nature-Based Solutions
Authors: Ramanathan S Arun , Versini Pierre-Antoine , Schertzer Daniel , Tchiguirinskaia Ioulia , Perrin Remi , Sindt Lionel
Published: March 2022

The hydrological behavior of granular substrates is of critical interest in Nature-Based Solutions (NBS) like green roofs. To simulate this behavior in a physically realistic manner it is indispensable to model the substrate’s Hydraulic Conductivity (HC) as it determines infiltration rate at various degrees of saturation. Since HC is directly dependent on water content retained by the substrate, it is necessary to physically model this Water Retention (WR) behavior too. Capillary water is stored or retained in pore spaces and this water content that can be retained by a substrate under different suction pressures is therefore dependent upon its Pore Size Distribution (PSD). Since pores in any granular media are spaces where grains are absent, their size distribution too is intrinsically related to the substrate’s Grain Size Distribution (GSD) which provides the probability of finding grains smaller than some diameter dgs. Although some earlier studies have attempted to model PSD, WR, and HC, they frequently use simplifying mono-fractal (fractal) approximations, whereas this study proposes a more generalized multifractal-based approach. Furthermore, while it is quite usual to incorporate pore tortuosity through some indirect parameter l in the HC model, a related ink-bottle effect which even though capable of affecting WR behavior is commonly ignored. Therefore this study suggests the use of a new parameter i in the WR model to physically represent this ink-bottle effect (a consequence of the substrate’s pore configuration or arrangement) which additionally takes into account the pore tortuosity without using l. The proposed models are validated using experimental measurements from 4 different commercially used green roof substrates.

Keywords: Multifractals, Non-linear geophysical systems, Cascade dynamics, Scaling, Hydrology, Green roof substrates.
Mapping the organic N distribution in the rhizosphere of maize
Authors: shen guoting , Khosrozadeh Sajedeh , Ghaderi Negar , Guber Andrey , Blagodatskaya Evgenia
Published: March 2022

The combination of two non-destructive 2D imaging methods: amino-mapping and zymography have been developed and applied to monitor organic nitrogen allocation in the rhizosphere of Zea mays L.  under contrasting nutrient treatments. Amino-mapping was based on the fluorescent reaction of o-phthaldialdehyde and β-mercaptoethanol enabling to estimate the content of labile organic N, playing an important role in soil nitrogen cycling. Amino-mapping was coupled with leucine-aminopeptidase zymography to quantify the amino-N release in the rhizosphere of maize grown under climate chamber conditions for 3 weeks. The combination of the two approaches enabled visualization of organic N hotspots either distinctly separated or overlapped with the hotspots of enzymatic activity. This work was conducted within the framework of the priority program 2089 “Rhizosphere spatiotemporal organization – a key to rhizosphere functions”, funded by German Research Foundation (DFG – Project number: 403664478). Seeds of the maize were provided by Caroline Marcon and Frank Hochholdinger (University of Bonn).
Why does Trichodesmium fix nitrogen during the day? Special biochemistry linking biogeochemical cycles.
Authors: Held Noelle , Waterbury John , Webb Eric , Kellogg Riss , McIlvin Matthew , Jakuba Michael , Valois Frederica , Moran Dawn , Sutherland Kevin , Saito Mak
Published: March 2022

Cyanobacteria of the genus Trichodesmium provide about 80 Tg of fixed nitrogen to the surface ocean per year and contribute to marine biogeochemistry, including the sequestration of carbon dioxide and mobilization of particulate iron. Trichodesmium fixes nitrogen in the daylight, despite the incompatibility of the nitrogenase enzyme with oxygen produced during photosynthesis. While the mechanisms protecting nitrogenase remain unclear, all proposed strategies require considerable resource investment. Here we describe a crucial benefit of daytime nitrogen fixation in Trichodesmium spp. that may counteract these costs. We analysed diel proteomes of cultured and field populations of Trichodesmium in comparison with the marine diazotroph Crocosphaera watsonii WH8501, which fixes nitrogen at night. Trichodesmium’s proteome is extraordinarily dynamic and demonstrates simultaneous photosynthesis and nitrogen fixation, resulting in balanced particulate organic carbon and particulate organic nitrogen production. Unlike Crocosphaera, which produces large quantities of glycogen as an energy store for nitrogenase, proteomic evidence is consistent with the idea that Trichodesmium reduces the need to produce glycogen by supplying energy directly to nitrogenase via soluble ferredoxin charged by the photosynthesis protein PsaC. This minimizes ballast associated with glycogen, reducing cell density and decreasing sinking velocity, thus supporting Trichodesmium’s niche as a buoyant, high-light-adapted colony forming cyanobacterium. To occupy its niche of simultaneous nitrogen fixation and photosynthesis, Trichodesmium appears to be a conspicuous consumer of iron, and has therefore developed unique iron-acquisition strategies, including the use of iron-rich dust. Particle capture by buoyant Trichodesmium colonies may therefore increase the residence time and degradation of mineral iron in the euphotic zone. These findings describe how cellular biochemistry defines and reinforces the ecological and biogeochemical function of these keystone marine diazotrophs, particularly their role as a microbial link in the nitrogen, carbon, and iron cycles. 
Drought self-propagation in drylands through moisture recycling
Authors: Keune Jessica , Schumacher Dominik L. , Dirmeyer Paul , Miralles Diego G.
Published: March 2022

Soil dryness modulates the surface energy balance through a reduction in evaporation, and can in turn affect both local and downwind precipitation. But when evaporation is heavily constrained by soil moisture, there is also a reduced local water vapor supply to the atmosphere, manifesting as downwind moisture deficits. Soil moisture–precipitation feedbacks as a whole — including surface heating-induced boundary layer processes and interactions, as well as changes in tropospheric moistening — have already been extensively investigated, particularly at the local scale. However, little is known about the non-local impact of soil moisture on precipitation. Here, we focus on the impact of water vapor reductions instigated by already existing soil drought, estimate the downwind effect on precipitation and thus gauge the potential for drought self-propagation. A Lagrangian approach constrained by observational and reanalysis data is employed to reveal the origins of water vapor, establishing a causal link between upwind evaporation and downwind rainfall. We assess the self-propagation of the 40 largest soil drought events from 1980 to 2016, obtained with a novel mathematical morphology method. Specifically, we estimate the reduction in precipitation caused by drought-stricken areas in the direction of drought propagation, and isolate the effect of upwind soil moisture drought from the influence of potential evaporation and circulation variability. Our results show that droughts self-propagate in subtropical drylands, owing to the strong decline in evaporation in response to soil water stress. For entire events, the reduction in precipitation along the propagation front can be more than 15%, and up to 30% for individual months. Our findings highlight that terrestrial ecosystems reliant on their own evaporation supplying  rainfall are most affected, and underline the susceptibility of arid environments to self-inflicted drought expansion.
Assessing the continuity of englacial layers across the Lambert Glacier catchment.
Authors: Sanderson Rebecca , Ross Neil , Callard Louise , Winter Kate , Napoleoni Felipe , Bingham Robert , Jordan Tom
Published: March 2022

The analysis of englacial layers using ice penetrating radar enables the characterisation and reconstruction of current and past ice sheet flow. To date, little research has been undertaken on the ice flow and englacial stratigraphy of the upper catchment of the Lambert Glacier. The Lambert Glacier catchment is one of the largest in East Antarctica, discharging ~16% of East Antarctica’s ice. Quantitative analysis of the continuity of englacial stratigraphy and ice flow has the potential to provide insight into the present-day and past flow regimes of the upper catchment of Lambert Glacier. Radar data from the British Antarctic Survey Antarctica’s Gamburtsev Province Project North (AGAP-N) aerogeophysical survey was analysed using the Internal Layer Continuity Index (ILCI). This approach identified, and characterised, a range of englacial structures and stratigraphy, including buckled layers in areas of increased ice velocity (>20ma-1) and continuous layering across subglacial highlands with low ice velocity adjacent to the central Lambert Glacier trunk. Overall, the analysis is consistent with the present-day ice-flow velocity field and long-term stability of ice flow across the Lambert catchment. However, disrupted layer geometry at the onset of the Lambert Glacier suggests a past shift in the position of the onset of ice flow. These results have implications for the future evolution of this major ice flow catchment, and East Antarctica, under a changing climate. The ILCI method represents a valuable tool for rapidly characterising englacial stratigraphy, and the study demonstrates the transferability of the method across Antarctica. The use of quantitative tools such as ILCI for the analysis of large radar datasets will be critical for projects such as AntArchitecture (https://www.scar.org/science/antarchitecture/home/) which aims to investigate the long-term stability of the Antarctic ice sheets directly from the internal architecture of the ice sheet.
Challenges and (structural) solutions for asbestos fibers crystallography.
Authors: Giacobbe Carlotta
Published: March 2022

  

The choice of studying nano and micro natural fibres can be exciting and lead to successful scientific stories, but not always results are immediate and it can take several years to get some.

One of the main challenges is to obtain an accurate structure analysis of natural samples, as they do not form crystals large enough for single-crystal x-ray diffraction (SC-XRD), and their analysis is often hampered by reflection overlap and the coexistence of multiple fibres linked together.

The advent of high-brightness, fourth generation synchrotron sources and improvements in X-ray focusing optics [1] has enabled new techniques for materials investigations with nanometre spatial resolution.

Possibilities for multiscale characterization for environmental mineralogy using the same probe, together with the high penetration power and coherence, are some of the most advantageous factors of synchrotron X-ray sources and the case of asbestos materials can benefit by the bright and small beam available in synchrotron facilities, especially at ID11, the Materials Science Beamline at the ESRF.

Challenges and results collected over the past 10 years studying natural fibres will be shown in this contribution.

 [1] Snigirev, A. A., Snigireva, I., Grigoriev, M., Yunkin, V., Di Michiel, M., Kuznetsov, S. & Vaughan, G. (2007). Proc. SPIE, 6795, 670506

 
Fish fossil remains from the Khartam Member, Khuff Formation in Central Saudi Arabia: Implications for placement of the Permo/Triassic Boundary
Authors: Babiker Jarrah , Humphrey John , Al-Ramadan Khalid , Payne Jonathan , Kaminski Michael , Alqubalee Abdullah
Published: March 2022

Recognition of the Permian/Triassic boundary in Saudi Arabia by previous researchers using a variety of methods has resulted in placement of the boundary at different stratigraphic levels. In this study, we discovered two lithological horizons containing fossil fish teeth (sharks and Actinopterygii) in different stratigraphic positions within the Khartam Member of the Khuff Formation. Thin-section petrography initially revealed the fossil fish teeth, while XRF, XRD, SEM, and QEMSCAN techniques were used to confirm the presence of biogenic apatite. Fish teeth collected from the two stratigraphic levels in the Khartam Member show distinct and different morphological features. The fossil assemblage recovered from the lower unit belongs to the classes Euselachii and Actinopterygii, while fish teeth from the upper unit belong to the shark genus Lissodus.  The stratigraphic position of the recovered Lissodus microfossils supports the previous placement of the Permo/Triassic boundary by Vaslet et al. (2005) and Crasquin-Soleau et al. (2006), who placed the boundary exactly at the stratigraphic boundary between the Lower and Upper Khartam Members. The results of this study do not corroborate the boundary placement by Eltom et al. (2016), who placed the Permo/Triassic boundary in a higher stratigraphic position within the Upper Khartam Member. Lissodus species are common from the Early Triassic to Late Cretaceous, suggesting new paleontological evidence for the placement of the Permo/Triassic boundary in Saudi Arabia.
Investigating the short-term ecomorphological evolution of a gravel-bed river
Authors: Latella Melissa , Notti Davide , Baldo Marco , Giordan Daniele , Camporeale Carlo
Published: March 2022

European watersheds have been subjected to different anthropic disturbances affecting their sediment budget and the morphodynamic asset in the last century, such as extensive mining, flow regulation, damming, land-use change, and embankment. As a response, gravel-bed rivers went through planform shifts, typically from multi- to single-thread configurations, and dramatic bed degradation.

The regulation of mining activity and the occurrence of major floods can (partially) restore river dynamism by redistributing sediments in the floodplain and reactivating secondary channels. Since the flood pulsing is an intrinsically random process, the overall behaviour of mined gravel-bed rivers is not always straightforward to understand, therefore hampering river management and restoration.

This work focuses on the Orco River (northwest Italy) case to study its short-term response to anthropic and hydrological forcing. For this purpose, we performed extensive field measurements and Light Detection and Ranging (LiDAR) data acquisition, integrating these data to reconstruct the morphological configuration of the selected site from 2019 to 2021 and map riparian vegetation biomass. Exploring the river plano-altimetric evolution, the sediment budget and the biomass variations, we investigated the prevalent eco-morphological processes to provide valuable indications for the Orco River management and a general benchmark for studies on gravel-bed rivers.
SHmax Orientation in the Northern Alpine Foreland from Stress-Induced Anisotropy in Nonlinear Elasticity
Authors: Aiman Yongki Andita , Delorey Andrew , Lu Yang , Bokelmann Götz , Group the AlpArray Working
Published: March 2022

The orientation of SHmax is commonly estimated from in-situ borehole breakouts and earthquake focal mechanisms. Borehole measurements are expensive, and therefore sparse, and earthquake measurements can only be made in regions with many well characterized earthquakes. Here we derive the stress-field orientation using stress-induced anisotropy in nonlinear elasticity. In this method, we measure the strain derivative of velocity as a function of azimuth. We use a pump-probe method which consists of measuring elastic wave speed using empirical Green’s functions (probe) at different points of the tidal strain cycle (pump) as in Delorey et al. (2021). The approach is applied to data from the AlpArray in the Alpine foreland region, where the orientation of maximum horizontal compressive stress is well-known from borehole breakouts and drilling-induced fractures.

Delorey, A., Bokelmann, G., Johnson, C., Johnson, P. Estimation of the orientation of stress in the Earth's crust without earthquake or borehole data. Nature Comm. Earth Environ. 2, 190 (2021). https://doi.org/10.1038/s43247-021-00244-1
The importance of InSAR data post-processing for the interpretation of geomorphological processes
Authors: Zocchi Marta , Antonielli Benedetta , Marini Roberta , Masciulli Claudia , Pantozzi Gianmarco , Troiani Francesco , Mazzanti Paolo , Scarascia Mugnozza Gabriele
Published: March 2022

A-DInSAR (Advanced Differential Synthetic Aperture Radar Interferometry) is widely acknowledged as one of the most powerful remote sensing tools for measuring Earth’s surface displacements over large areas, and in particular landslides. The Persistent Scatterer Interferometry (PS-InSAR or PSI) is a common A-DInSAR multitemporal technique, which allows retrieving displacement measurements with sub-centimetric precision. Characterization and interpretation of landslides can greatly benefit from the application of A-DInSAR post-processing tools, especially when extremely slow-moving phenomena are not detectable by classical geomorphological investigations, or when complex displacement patterns need to be highlighted. Detailed representations of the spatial and temporal evolution of the processes provide useful constraints during the planning stages of reconstructions and for land use purposes.
The present study is part of a broader national project, focused on updating and monitoring landslide-prone slopes interacting with urban centres in the Central Apennines (Italy), by using both geomorphological and A-DInSAR analysis. Therefore, although field surveys permitted the systematic updating of the available landslide inventories, in most cases, clear indications of displacement were outlined only by the SAR interferometry results. In this regard, the preliminary results of the ongoing research focus on specific post-processing analyses of interferometric data performed in the study area. 
A specific PS-toolbox software, developed by NHAZCA S.r.l. as a set of post-processing plugins for the open-source software QGIS, was specifically designed to enhance spatial and temporal deformation trends of the PSI results, as well as for visualizing the differences between multi-satellite datasets. Moreover, the PS-toolbox allowed depicting subtle surface patterns within the landslide area, shedding light on kinematics and style of activity of slope instabilities.  
In complex morphological conditions, as the Apennines mountainous regions, the geometric distortions and the site coverage percentage can lead to a lack of information. Therefore, we compared the coverage of PSs and the accuracy of the surface velocity maps produced using different InSAR tool packages on both Sentinel-1 and COSMO-SkyMed scenes. Thus, the comparison of the resulting datasets allowed their validation in terms of measured displacements and reliability for further processing.
Observational and numerical evaluation of the pedestrian-level microclimatic effect of street trees in a highly-compact city
Authors: Segura Ricard , Krayenhoff Scott , Martilli Alberto , Badia Alba , Estruch Carme , Ventura Sergi , Villalba Gara
Published: March 2022

The application of nature-based solutions in urban areas to mitigate the harmful effects of urban overheating and to make cities more resilient to heat waves has gained the attention of city planners and researchers in the last decades. Street trees are an important driver of street microclimate through shadowing and transpiration cooling, which are key components in the improvements of thermal comfort. While several observational campaigns have been carried out in low and medium-density residential areas, little research has been focused in highly-compact city centres, where the impact of built elements on the local climate is expected to be stronger. In this context, Urban canopy models (UCM) with integrated trees are useful tools because they represent the impact of street trees on neighbourhood-scale climate, resolving the interactions between buildings, trees and the atmosphere. These models enable the assessment of outdoor human thermal exposure for diverse urban morphologies and allow the evaluation of greening scenarios.

In this study, we present the results of a micrometeorological measurement campaign inside the city of Barcelona (Spain) for two cloud-free summer days. Vehicle transects were completed along two parallel streets with different tree densities but identical street geometry, recording upward and downward radiation fluxes, air temperature and humidity. Assessment of urban tree impacts on microclimate is supplemented by meteorological simulations using the multi-layer UCM Building Effect Parameterization with Trees (BEP-Tree), which considers the vertical variation of the combined impacts of vegetation and building on urban canopy layer climate. Comparing observed pedestrian level air temperatures between the two canyons, we can see that the impact of tree densities varies with the regional weather, with air temperatures up to 2.7 oC higher in the street with low tree density compared to the one with denser trees for a day with the wind direction perpendicular to the direction of the streets. The BEP-Tree simulations demonstrate good agreement with the observations in terms of temperature and radiation, and they are able to capture the different diurnal evolution of temperature and radiation between the two streets.
Survey on the vulnerability and resilience of southern Italian forests to extreme climate events 
Authors: Italiano Santain Settimio Pino , Rita Angelo , Borghetti Marco , Colangelo Michele , Cantiani Mario , Lapolla Antonio , Ripullone Francesco
Published: March 2022

Forest dieback phenomena occur all over the world and have been mainly attributed to extreme droughts and heatwaves. These phenomena are more pronounced in the Mediterranean basin, causing a significant impact on the structure, composition, and productivity of forests. Understanding the response of Mediterranean forests to extreme climate events is of paramount importance to assess their vulnerability to such phenomena. The present study combined both radial growth data and remotely sensed indices (i.e., Normalized Difference Vegetation Index, NDVI) to analyse the vegetation status of selected deciduous forest stands impacted by the summer 2017 heatwave. We surveyed several sites of the Southern Apennines mountains range in order to: I) investigate the growth response of forest vegetation in terms of resilience and resistance and II) characterize their ability to recover after extreme climatic events. Overall, we observe a significant reduction in radial growth after 2017 in all studied stands. Moreover, the vegetation shows clear signs of "recovery" that are strictly dependent on species-specific and site-specific conditions. In this study we will highlight how these stands responded to the heatwave occurred in the 2017 and how these events can affect the future vegetation dynamics either in terms of growth and evolution of Mediterranean ecosystems.
Features of broken crystals reveal the fracturing and healing of basaltic magmas during explosive volcanic eruptions
Authors: Taddeucci Jacopo , Cimarelli Corrado , Alatorre-Ibarguenguoitia Miguel Angel , Delgado-Granados Hugo , Andronico Daniele , Del Bello Elisabetta , Scarlato Piergiorgio , Di Stefano Flavio
Published: March 2022

The eruption of fragmental magma of basaltic composition is the most frequent type of explosive volcanism on Earth and in the Solar System, with eruptions spanning from centuries of persistent, weak explosions, through days to months of lava fountains and ash emissions, to rare, global-scale catastrophic events. The mechanism through which continuous magma fragments into volcanic particles is central in governing eruption dynamics and the ensuing hazards. However, the mechanism of fragmentation of basaltic magmas is still disputed, with both viscous and brittle mechanisms having been proposed for different eruptive styles. Here we carry out textural analysis of the products of ten eruptions from seven volcanoes by Scanning Electron Microscope. We find broken crystals surrounded by intact glass and other features that testify to the brittle fragmentation of basaltic magmas during explosive activity differing in style, intensity and magnitude. We then replicated the natural textures of broken crystals in laboratory experiments where variably crystallised basaltic melt was fragmented by rapid deformation. The experiments reveal that crystals are broken by the propagation of a network of fractures through magma, and that afterwards many of the fractures heal by viscous flow of the melt. Fracturing and healing affect gas mobility, stress distribution, and bubble and crystal size distributions in magma. Our results challenge the idea that the grain size distribution of basaltic eruption products reflects the density of the fractures that initially fragmented the magma. Unrecognised broken crystals and accompanying textures appear in previous literature covering many eruptions spanning Hawaiian lava fountains, catastrophic Plinian events, and more. We conclude that brittle fragmentation and subsequent healing are not specific to some eruption style or pyroclast type, but are ubiquitous factors controlling basaltic explosive volcanism.
Geoacoustic inversion of shipping noise at two closely spaced vertical arrays for estimation of gassy sediment parameters
Authors: Yarina Marina , Lunkov Andrey , Godin Oleg , Katsnelson Boris
Published: March 2022

Results of experimental research for geoacoustic inversion using low frequency (20 to 500 Hz) shipping noise in shallow water waveguide with gassy sediments are presented. The inversion is based on modal dispersion analysis.

Experiments were carried out in the Sea of Galilee (also known as Lake Kinneret, Israel) having maximum depth of ~40 m and remarkable concentration of methane bubbles in the upper sedimentary layer. Moving R/V "Hermona" was used as a low frequency sound source, having wide-band spectrum. As a receiving system, two synchronized vertical line arrays (VLAs) with 10 hydrophones at each one, spanning the water column with 3 m-interval were used. VLAs were located at the center of the lake (the water depth is ~40 m) with the distance 40 m between them. R/V "Hermona" was moving along straight line joining VLAs, at the range of up to 1 km from the VLA.

A method for extracting the frequency dependence of modal phase speed cph (modal dispersion curves) from shipping noise recorded by two closely spaced and synchronized VLAs is proposed. Firstly, at each frequency ω, the noise is spatially filtered at both VLAs using ψ-functions calculated by solving the second order differential equation for eigenfunctions, but with only one boundary condition (free release surface) and variable horizontal wavenumber q=ω/cph. The experimental sound speed profile in the water column is taken into account in the calculations. Secondly, the ratio of complex modal amplitudes at both VLAs is calculated and multiplied by a factor of eiqΔr. The real part of the resulting two-dimensional (ω,cph) structure exhibits the modal dispersion curves. The obtained set of dispersion curves are used as an input for geoacoustic inversion. Bottom parameter estimates are compared with those obtained by other methods, including direct core sampling.