bluuebunny/crossref_metadata_2025 huggingface dataset:
Pyroclastic rocks from Kanchanaburi and Uthai Thani Province, Inthanon Zone, Western Thailand
Authors: Jatupohnkhongchai Suwijai , Salyapongse Sirot , Phajuy Burapha , Gallhofer Daniela , Hauzenberger Christoph
Published: March 2020

A series of pyroclastic rocks are mapped as a Silurian-Devonian unit in the Kanchanaburi-Uthai Thani area, Western Thailand, which belongs to the Inthanon Zone. These pyroclastic rocks were discovered and described for the first time in 1977 and mentioned in the 1:250,000 Suphanburi geologic map sheet and report. Since then these rocks were poorly investigated and their formation and geotectonic setting is unclear. As a result, we report petrographic, geochemical and geochronological data of these pyroclastic rocks. Petrographically, the pyroclastic rocks can be described as a meta-quartz-K-feldspar crystal tuff, a meta-quartz crystal tuff, and a meta-lithic tuff. They are made up of mm sized clasts in a finely grained matrix. The clasts consist of potassium feldspar, rounded quartz, embayed quartz, trachytic and metasedimentary rock clasts embedded in a highly altered devitrified fine-ash matrix containing sericite.

The whole-rock composition shows enrichments in SiO2 and K2O and a strong depletion in CaO and Na2O which is related to late alteration of the volcanoclastic rocks. Based on the immobile element classification plot of Pearce 1996, the tuffs can be classified as trachyandesite, trachyte, dacite and rhyolite. Their chondrite-normalized REE patterns display light REE enrichment with nearly flat heavy REE and a negative Eu anomaly, typical for calcalkaline volcanic rocks. Most samples fall in the volcanic arc granites field in the granite discrimination diagrams of Pearce 1984.

Zircons extracted from the tuffs will be used to constrain their crystallization age by U-Pb LA-MCICPMS dating. This allows us to constrain the age of formation and to place this in context with the closure of the Paleotethys.
The Identification of Hydrological Threshold Variables
Authors: Veinbergs Arturs , Lagzdins Ainis
Published: March 2020

The threshold groundwater levels limiting the drainage depth and tile drain runoff as well as runoff recession and runoff partitioning are case-specific.  These are the characteristics that are usually necessary for setting up and calibration processes for such models as HYPE (Lindström et al. 2010) and SWAT (Neitsch et al. 2002).  

The objective of the present study is to identify the thresholds of groundwater levels and runoff rates that limit the formations of such runoff components as base flow and tile drain runoff. This study utilizes the data that represents the daily runoff measurements in open ditch with such characteristics as total length 2.4 km, basin area 368 ha, loamy soils, agricultural lands with subsurface drainage systems installed in 98% of the area, average tile depth 1.2m below ground surface.

The runoff components were partly separated from the daily runoff hydrographs through the analysis of storm runoff recession gradients (eq.1) and groundwater level fluctuations during the period from 2006. to 2015. Baseflow and tile drain runoff ware calculated as beeing linearly dependent on daily groundwater level fluctuations (eq.2).

  Rci=Qi+1/Qi,     (1)

Qx=fx(GWT)=ax*GWT+bx ,      (2)

Where: Rci – recession gradient; Qi and Qi+1– runoff of day i and i+1 respectively;  Qx – runoff component; GWT– groundwater level; ax and bx– slope and intercept of a linear function.

Nash-Sutcliffe efficiency (NSE) and percent bias (PBIAS) were used for comparison of calculated and separated runoff components.

The results indicate a decrease in drainage intensity and reduction in specific yield during the study period. The groundwater level of 1.18m below ground surface limit the existence of the tile drain runoff, that, furthermore,  is similar for rising and falling groundwater level. The results reveal that runoff could be contributed by 35%, 57% and 8% of baseflow, tile drain runoff and surface runoff respectively.
Occurrence and characteristics of ice-debris landforms in Poiqu basin (central Himalaya)
Authors: Bolch Tobias , Rastner Philipp , Pronk Jan Bouke , Bhattacharya Atanu , Liu Lin , Hu Yan , Zhang Guoqing , Yao Tandong
Published: March 2020

Rock glaciers and other ice-debris landforms (I-DLs) are an important part of the debris-transport system in high mountains and their internal ice could provide a relevant contribution to water supply especially in dry regions. Recent research has shown that I-DLs are abundant in High Mountain Asia, but knowledge about their occurrence and characteristics is still limited.

We are therefore investigating I-DLs in the Poiqu basin (~28°17´N, 85°58´E) – central Himalaya/southern Tibetan Plateau using remote sensing aided by field observations. We use very high-resolution stereo Pleiades data from the contemporary period and stereo Corona and Hexagon data from the 1970s to generate digital elevation models, applied satellite radar interferometry based on ALOS-1 PALSAR and Sentinel-1 SAR data and feature tracking using Sentinel-2 and the Pleiades data. Generated DEMs allowed us to create a hillshade to support identification, to derive their topographical parameters and to investigate surface elevation changes. I-DLs were identified and classified based on their characteristic shape, their surface structure and surface movement. Field observationssupported the identification of the landforms.

We found abundant occurrence of rock glaciers (with typical characteristics like lobate-shaped forms, ridges and furrows as well as steep fronts) but also significant movements of both former lateral moraines and debris-slopes in permafrost area. Preliminary results revealed the occurrence of more than 350 rock glaciers covering an area of about 21 km2. About 150 of them are active. The largest rock glacier has an area of 0.5 km2 and three have an area of more than 0.3 km2. The rock glaciers are located between ~3715 m and ~5850 m with a mean altitude of ~5075 m a.s.l.. The mean slope of all rock glaciers is close to 17.5° (min. 6.8°, max. 37.6°). Most of the rock glaciers face towards the Northeast (19%) and West (18.5%). Surface elevation changes between the 1970s and 2018 show no significant changes but indicate slight elevation gain at the front of active rock glaciers caused by their downward movements.

Work will be continued to generate an inventory of all I-DLs in the study area including information about their activity and surface elevation changes.
Towards Slow Earthquakes Forecasting
Authors: Gualandi Adriano , Avouac Jean-Philippe , Michel Sylvain , Faranda Davide
Published: March 2020

Slow Slip Events (SSEs) are episodic slip events that play a significant role in the moment budget along subduction megathrust. They share many similarities with regular earthquakes, and have been observed in major subduction regions like, for example, Cascadia, Japan, Mexico, New Zealand. They show striking regularity, suggesting that it might be possible to forecast their size and timing, but the prediction of their extension and exact timing is still yet to come. They certainly are a great natural system to study how friction works at scale of the order of hundreds or thousands of km, and their recurrence time being much shorter than that of regular earthquakes, they give us the possibility to study multiple cycles and test their predictability.
Here we focus on the Cascadia region, where SSEs recur every about 1 or 2 years, depending on the latitude. The study of GPS position time series during the time span ranging from 2007 to 2017 has revealed a low-dimensional (< 5) non-linear chaotic dynamics with a predictable horizon (calculated as the inverse of the metric entropy) in the order of days to months for causally filtered data. It is notable that the increase of instantaneous dimensionality of the attractor seems to constitute a reliable precursor of the large SSEs. The causal filter adopted to reach this conclusion introduces a group delay larger than the predictability horizon time, meaning that this approach cannot be used for real-time forecasting. We thus test alternative filters and data driven approaches (e.g., dynamic mode decomposition) for real-time characterization of the attractor’s properties and evolution. In any case, we conclude that SSEs in Cascadia can be described as a deterministic, albeit chaotic, system rather than as a random process. As SSEs might be regarded as earthquakes in slow motion, regular earthquakes might be similarly chaotic and predictable for short amount of times. If the relation between predictability horizon and the duration of the instability (i.e., slipping event duration) holds also for regular earthquakes, this would imply that earthquakes long-term predictions are intrinsically impossible, and the predictable horizon would be only a fraction of the regular earthquakes typical duration (10-100 s for M>6 earthquakes).
Forest fire selectivity patterns in respect to topography during the period 1984-2015 in selected places in Greece
Authors: Stamou Zoi
Published: March 2020

The aim of this study is to assess wildland fire selectivity patterns in respect to topography in selected places in South Greece including eleven NUTS-3 counties of which two are islands, from 1984 to 2015. Fire scar perimeters within the time window 1984-2015 were delineated from freely available Landsat images from USGS and ESA archives and maps of fire frequency and fire return interval were finally created. Derived from eight different Landsat scenes (path/row), almost six thousands satellite images processed and more than five thousand and eight hundred fire perimeters were extracted, in order to reconstruct the fire history of South Greece, in a thirty two years’ period. Fireperimeters within each year of fire occurrence were compared against the available to burn under complete random processes to identify selectivity patterns in respect to topography.
It is clear that even though there is a decreasing trend in east, north east and south east facing aspects, fire selectivity in these areas is higher as compared to the available to burn. On the other hand there is a considerable rising in the trend of fire selectivity on west, southwest and northwest facing aspects. In terms of slope, lower- and mid-slopes tend to burn more than the available, opposite to upper- and higher –slopes. In addition, upper-elevation areas (over 800 meters), are negative related to wildfires while most of wildfires occur in altitude from 100 to 600 meters.
Impacts of Climate Change and Remote Natural Catastrophes on EU Flood Insurance Markets
Authors: Tesselaar Max , Botzen W. J. Wouter , Aerts Jeroen C. J. H.
Published: March 2020

Flood insurance coverage can enhance financial resilience of households to changing flood risk caused by climate change. However, due to increasing risk in many areas, premiums are likely to rise, which may cause insurance to become unaffordable for low-income households. This issue can become especially prominent in high-risk areas, when premiums are risk-reflective. Consequently, increasing premiums can reduce the demand for insurance coverage when this is optional, as individuals often underestimate the flood risk they face. After a flood, uninsured households then have to rely on private savings or ex-post government disaster relief. This situation is suboptimal as households may not save sufficiently to cover the damage, and government compensation can be uncertain. Using a modeling approach we simulate unaffordability and uptake of various forms of flood insurance systems in EU countries. To do this, we build upon and advance the “Dynamic Integrated Flood Insurance” (DIFI) model, which integrates flood risk simulations, with an insurance sector and a consumer behavior model. We compute the results using various climatic- and socio-economic scenarios in order to assess the impact of climate- and socio-economic change for flood insurance in the EU. Furthermore, we assess the impact of remote natural disasters on flood insurance premiums in EU countries, which occurs through the global reinsurance market. More specifically, after large natural disasters or compound events occurring outside the EU, which are likely to occur more often due to climate change, reinsurance premiums can temporarily rise as a result of a global “hard” capital market for reinsurers. The higher cost of capital for reinsurers is then transferred to households in the EU through higher flood insurance premiums. We find that rising average, and higher variance, of flood risk towards the end of the century can increase flood insurance premiums, and cause higher premium volatility resulting from global reinsurance market conditions. The rise in premiums increases unaffordability of insurance coverage and results in declining demand for flood insurance. A proposed policy improvement is to introduce a public reinsurance system for flood risk, as governments can often provide cheaper reinsurance coverage and are less subject to volatility on capital markets. Besides this, we recommend a limited degree of premium cross-subsidization to limit the growth of premiums in high-risk areas, and insurance purchase requirements to increase the level of financial protection against flooding.  
Permeability heterogeneity during sandstone compaction
Authors: Meredith Philip , Brantut Nicolas , Baud Patrick
Published: March 2020

Compaction of porous sandstones is generally associated with a reduction in permeability. Depending on porosity and other microstructural characteristics, compaction may be diffuse or localised in bands. Compaction bands have been shown to act as barriers to fluid flow and therefore reduce permeability perpendicular to the band orentiation, and thus also introduce permeability anisotropy. Additionally, the localised nature of compaction bands should also introduce strong permeability heterogeneity. We present new experimental data on sandstone compaction combining acoustic emission monitoring and spatially distributed pore fluid pressure measurements, allowing us to establish how permeability heterogeneity develops during progressive compaction. Three sandstones were tested in the compactant regime: Locharbriggs sandstone, which is microstructurally heterogeneous with beds of higher and lower initial permeability; a low porosity (21%) Bleurville sandstone, which is microstructurally homogeneous and produces localised compaction bands; and a high porosity (24%) Bleurville sandstone, which is also homogeneous but produces compaction in a more diffuse pattern. At regular intervals during compactive deformation, a constant pore pressure difference was imposed at the upper and lower boundaries of the cylindrical samples, and steady-state flow allowed to become established. Following this, local pore pressure measurements were made at four locations, allowing us to derive estimates of the local permeability. In all samples, progressive compaction produced overall reductions in permeability. In addition, localised compaction also produced internal reorganisation of the permeability structure. Localised compaction bands caused local decreases in permeability, while more diffuse compaction produced a more homogeneous overall reduction in permeability.

 
Imaging seafloor instabilities using very high-resolution deep-towed multichannel seismic data in the Gulf of Lions (NW Mediterranean)
Authors: Badhani Shray , Cattaneo Antonio , Colin Florent , Marsset Bruno , Urgeles Roger , Leroux Estelle , Dennielou Bernard , Rabineau Marina , Droz Laurence
Published: March 2020

The Gulf of Lions (GoL) is a passive margin of about 200 km long and 70 km wide with main sediment supply from the Rhone River supplying Alpine sediments to the Rhone delta. Submarine landslides in the GoL are widespread from the upper slope to the deep basin, within the canyon flanks and in the interfluves of major canyons. The two main submarine landslides present in the GoL are the Eastern Rhône Interfluve Slide (ERIS) and an unnamed slide complex on the western side of the Petit Rhone Canyon. Their resulting mass transport deposits (MTDs), the Rhone Eastern MTD (REMTD) and the Rhone Western MTD (RWMTD) have previously been described in detail in several studies. However, due to the lack of high-resolution multidisciplinary datasets, such as high-resolution seismic, sediment cores, and in-situ geotechnical measurements, a detailed analysis of weak layers and preconditioning factors was never performed. Here, we present a suite of a multidisciplinary dataset; particularly very high-resolution deep-towed multichannel seismic data acquired using Ifremer’s in-house acquisition system SYSIF (SYstème SIsmique de Fond) to assess seafloor instabilities in the GoL. The objectives of this study are twofold and aimed at 1) using deep-towed multichannel seismic data to capture the internal structure of the mass-wasting products previously imaged as seismically transparent or chaotic intervals in conventional seismic data; 2) using multidisciplinary dataset to analyse the basal surfaces of slope failures in the GoL. For the first time, the newly-acquired SYSIF data show in unprecedented detail the internal structure of mass-transport deposit along with small-scale slope failures. We present here an example of a failure that consists of slide blocks, folded and faulted strata with remnant stratigraphy previously associated with a transparent or chaotic facies in the conventional reflection seismic data. The combination of deep-towed seismic and sedimentological data, as well as in-situ measurements allowed us to analyse and characterize the nature of the basal surface of the slope failures in greater detail. We show that the basal surfaces of the recurring slope failures mainly consist of fine-grained clay-rich sediments as compared to turbiditic sequences typical of Rhone turbiditic system. Such observations suggest that greater degree of lithological heterogeneity in sedimentary strata promotes slope failure in the GoL, most likely related to higher liquefaction potential of coarser-grained material, excess pore pressure and possibly resulting variation in sediment strength.
A software framework for optimizing the design of spaceborne hyperspectral imager architectures
Authors: Erickson Adam , Poulter Benjamin , Thompson David , Okin Gregory , Serbin Shawn , Wang Weile , Schimel David
Published: March 2020

Quantifying the capacity, and uncertainty, of proposed spaceborne hyperspectral imagers to retrieve atmospheric and surface state information is necessary to optimize future satellite architectures for their science value. Given the vast potential joint trade-and-environment-space, modeling key ‘globally representative’ points in this n-dimensional space is a practical solution for improving computational tractability. Given guidance from policy instruments such as the NASA Decadal Survey and the recommended Designated Target Observables, or DOs, the downselect process can be viewed as a constrained multi-objective optimization. The need to simulate imager architecture performance to achieve downselect goals has motivated the development of new mathematical models for estimating radiometric and retrieval uncertainties provided conditions analogous to real-world environments. The goals can be met with recent advances that integrate mature atmospheric inversion approaches such as Optimal Estimation (OE) that includes joint atmospheric-surface state estimation (Thompson et al. 2018) and the EnMAP end-to-end simulation tool, EeteS (Segl et al. 2012), which utilizes OE for inversions. While surface-reflectance and retrieval simulation models are normally run in isolation on local computing environments, we extend tools to enable uncertainty quantification into new representative environments and thereby increase robustness of the downselect process by providing an advanced simulation model to the broader hyperspectral imaging community in software-as-a-service (SaaS). Here, we describe and demonstrate our instrument modeling web service and corresponding hyperspectral traceability analysis (HyperTrace) library for Python. The modeling service and underlying HyperTrace OE library are deployed on the NASA DISCOVER high-performance computing (HPC) infrastructure. An intermediate HTTP server communicates between FTP and HTTP servers, providing persistent archival of model inputs and outputs for subsequent meta-analyses. To facilitate enhanced community participation, users may simply transfer a folder containing ENVI format hyperspectral imagery and a corresponding JSON metadata file to the FTP server, from which it is pulled to a NASA DISCOVER server for processing, with statistical, graphical, and ENVI-formatted results subsequently returned to the FTP server where it is available for users to download. This activity provides an expanded capability for estimating the various science values of architectures under consideration for NASA’s Surface Biology and Geology Designated Observable.
Mineral interpretation results using deep learning with hyperspectral imagery
Authors: Bell Andrés , Del-Blanco Carlos Roberto , Jaureguizar Fernando , García Narciso , Jurado María José
Published: March 2020

Minerals are key resources for several industries, such as the manufacturing of high-performance components and the latest electronic devices. For the purpose of finding new mineral deposits, mineral interpretation is a task of great relevance in mining and metallurgy sectors. However, it is usually a long, costly, laborious, and manual procedure. It involves the characterization of mineral samples in laboratories far from the mineral deposits and it is subject to human interpretation mistakes. To address the previous problems, an automatic mineral recognition system is proposed that analyzes in real-time hyperspectral imagery acquired in different spectral ranges: VN-SWIR (Visible, Near and Short Wave Infrared) and LWIR (Long Wave Infrared). Thus, more efficient, faster, and more economic explorations are performed, by analyzing in-situ mineral deposits in the subsurface, instead of in laboratories. The developed system is based on a deep learning technique that implements a semantic segmentation neural network that considers spatial and spectral correlations. Two different databases composed by scanned drilled mineral cores from different mineral deposits have been used to evaluate the mineral interpretation capability. The first database contains hyperspectral images in the VN-SWIR range and the second one in the LWIR range. The obtained results show that the mineral recognition for the first database (VN-SWIR band) achieves an 86% in accuracy considering the following mineral classes: Actinolite, amphibole, biotite-chlorite, carbonate, epidote, saponite, whitemica and whitemica-chlorite. For the second database (LWIR band), a 90% in accuracy has been obtained with the following mineral classes: Albite, amphibole, apatite, carbonate, clinopyroxene, epidote, microcline, quartz, quartz-clay-feldspar and sulphide-oxide. The mineral recognition capability has been also compared between both spectral bands considering the common minerals in both databases. The results show a higher recognition performance in the LWIR band, achieving a 96% in accuracy, than in the VN-SWIR bands, which achieves an accuracy of 85%. However, the hyperspectral cameras covering VN-SWIR range are significantly more economic than those covering the LWIR range, and therefore making them a very interesting option for low-budget systems, but still with a good mineral recognition performance. On the other hand, there is a better recognition capability for those mineral categories with a higher number of samples in the databases, as expected. Acknowledgement: This research was funded the EIT Raw Materials through the Innovative geophysical logging tools for mineral exploration - 16350 InnoLOG Upscaling Project.
Degradation of terrigenous organic matter on the East Siberian Arctic Shelf assessed by lipid and lignin oxidation products
Authors: Matsubara Felipe , Wild Birgit , Martens Jannik , Wennström Rickard , Tesi Tommaso , Dudarev Oleg , Shakhova Natalia , Semiletov Igor , Gustafsson Örjan
Published: March 2020

Warming-induced permafrost thawing is expected to intensify the remobilization of terrigenous organic matter (terrOM) to the East Siberian Arctic Shelf (ESAS) via increasing river discharge and coastal erosion. Earlier studies have focused on source apportionment and transport of terrOM, with less emphasis on its degradation state during cross-shelf transport. Since degradation of terrOM is the link between permafrost thawing and release of GHGs such as CO2, this study focuses on the degradation characteristics. Hence, the main objective of this study is to assess the patterns of terrOM degradation across the East Siberian Arctic Shelf using molecular proxies that are specific to terrOM.

Lignin phenols and high molecular weight (HMW) n-alkanes and n-alkanoic acids are only produced by terrestrial plants which make them suitable biomarkers to assess degradation of terrestrial material throughout the ESAS. The lignin-based proxies acid to aldehyde ratios of vanillyl (Vd/Vl) and syringyl (Sd/Sl) structural units, as well as the ratio of 3,5-dihydroxybenzoic acid over vanillin (3,5-Bd/V) are expected to increase during degradation under oxic conditions. Fresh terrestrial plant material is predominated by long odd-numbered (>C25) and even-numbered (>C24) carbon chain length of n-alkanes and n-alkanoic acids, respectively. This dominance is described in the Carbon Preference Index (CPI). When degradation takes place, CPI values decrease accordingly, describing how much of the original material was preserved. Ratios of HMW n-alkanoic acids to HMW n-alkanes are also expected to decrease during microbial degradation owing to preferential loss of functional groups.

The data show increasing Vd/Vl, Sd/Sl and 3,5-Bd/V ratios, and decreasing HMW n-alkanes CPI values toward the outer shelf, consistent with continuous degradation of terrOM across the ESAS. While Vd/Vl and HMW n-alkane CPI did not show strong differences between east and west, Sd/Sl ratios were highest in the outer western ESAS, and 3,5-Bd/V ratios were highest in the outer east. These differences may reflect different terrOM pools along the ESAS due to differences in vegetation zones releasing the input material through river discharge and coastal erosion. In contrast, HMW n-alkanoic acid to HMW n-alkane ratio and HMW n-alkanoic acid CPI showed inconsistent patterns across the ESAS; reasons for it are currently being investigated. These results will also be complemented by additional biomarkers to better understand the degradation of terrOM during cross-shelf transport.
The hazard and risk assessment of Taipei Metropolitan through earthquake scenario from open data
Authors: Hsu Ming-Kai , Ma Kuo-Fong , Chan Chung-Han , Schorlemmer Danijel
Published: March 2020

    Modeling seismic hazard based on the ground motion scenario through numerical simulation could enhance the earthquake prevention strategy, especially for highly populated urban region. Taiwan as an earthquake prone country, it is important to provide the earthquake awareness through multiple risk (impact and loss) scenarios. These end-to-end hazard and risk scenarios will increase the resilience of society to extreme earthquake events by identifying the factors critical to society in the earthquake hazard and risk scenarios. The results will help to provide resilient urban development and future design by understanding and strengthening societal capacity for resilience.  Taking advantage on the open data policy, we collected the dense seismic data and open exposure data in buildings in the Taipei Metropolitan to develop the task of the end-to-end hazard and risk scenarios. The seismic hazard was made through earthquake scenario from the rupture of the Shanchiao fault, which is to the west of the Taipei basin. The topography and velocity structure of the basin were taken into account in the simulation to explore the long duration of shaking and basin effect, together with thorough evaluation on site amplification of densely populated seismic stations within the basin. We explore the assessment of scenario-based loss estimation with the exposure model of 500x500 meter grid-based data from National Science and Technology Center for Disaster Reduction (NCDR) and the governmental open data consisted of Taipei building user license information and open street map shape file data. For building damage estimation, we developed building damage based fragility curves including 1999 Chi-Chi and 2016 Meinong earthquakes for the ground motion in PGA, PGV and Intensity. We also considered the acceleration response spectrum (Sa) and velocity response spectrum (Sv) in different interval of period. Through the development of the end members, we hope to build the earthquake hazard and risk scenarios to ensure effective disaster response from up-to-date, open, transparent and reliable risk-data.
Assessing the reactivity of magnesium oxide calcinated at different temperatures for understanding its role in degradation processes
Authors: Bader Tobias , Diekamp Anja
Published: March 2020

In Tyrol, Austria, dolomite rock was commonly used as raw material for historic mortars and plasters. During calcination of dolomite rock, almost equal amounts of calcium oxide and magnesium oxide are produced. While the reactivity of calcium oxide is well known, the reactivity of magnesium oxide is still not completely understood. Within this study, the reactivity of magnesium oxide obtained from calcination at different temperatures (600 - 1000 °C) will be examined. For this purpose, natural magnesite (Hochfilzen, Tyrol) will be used instead of natural dolomite rock in order to minimise the influence of calcium oxide on the wet slaking curves. Both, calcination and slaking of magnesite will be studied with the help of X-ray diffraction analysis and thermogravimetric analysis. The gained knowledge is believed to be beneficial for improving the understanding of degradation processes. The study was performed within the Interreg V-A Italy-Austria project named DOLOMIA (ITAT 2036) with the funding by INTERact and the European Regional Development Fund (ERDF) being grateful acknowledged.
Towards a better understanding and modelling of Hortonian overland flow during flash flooding
Authors: Villinger Franziska , Loritz Ralf , Zehe Erwin
Published: March 2020

In the last decade, several small-scale flash floods in south-west Germany have shown that there is great danger due to quickly rising water levels and soil erosion (BRONSTERT ET AL., 2018). Flash floods are triggered by high intensity rainfall events, where rapid surface (Horton) or shallow subsurface flows dominate runoff generation. Especially surface runoff can result in great damage as it is a highly localized process with large potential to perform physical work on the landscape and on infrastructure. Model characteristics can vary greatly in space and time, reliable predictions remain challenging, especially if hydrological models are applied, based on empirical rainfall-runoff relationships. It is hence a long-standing vision to use models which are more physically based and rely on less empirical relations, to be able to improve our ability to predict the occurrence and dimension of flash floods.

In this study we use the physically based model CATFLOW, which is firstly setup to simulate flash floods for a small rural catchment. We perform virtual experiments to test a) if the model is capable to predict two observed flash floods caused by two convective rainfall extremes and b) which model landscape characteristics are the most sensitive. Thirdly, we provide evidence that different standardized temporal rainfall patterns used in flood design strongly affect simulated flooding when being compared to simulations with the real observed pattern. Last, we discuss why the two observed flash floods differed strongly in peak and volume, although the two convective events were similar in depth, duration and mean intensity and antecedent wetness was similar as well. We assume that due to the lower degree of plant cover during the earlier first event, the likelihood for raindrops hitting bare soil was higher, causing more surface sealing and hence more surface runoff occurred. Plant cover influencing soil resistance and soil texture are besides meteorological forcing a main control of flash floods.
Coupled ice-climate simulation of future Greenland ice sheet evolution: mechanisms, thresholds and feedbacks for accelerated mass loss
Authors: Vizcaino Miren , Muntjewerf Laura , Sellevold Raymond , Ernani da Silva Carolina , Petrini Michele , Thayer-Calder Katherine , Scherrenberg Meike , Bradley Sarah , Fyke Jeremy , Lipscomb William , Lofverstrom Marcus , Sacks William
Published: March 2020

The Greenland ice sheet (GrIS) has been losing mass in the last several decades, with a current contributing of around 0.7 mm per year to global mean sea level rise (SLR). Projections of future melt rates are often derived from standalone ice sheet models, forced by data from global or regional climate models. In many cases, the surface mass balance parameterization relies on simplified schemes that relate melt with surface temperature.

In this study, we present a mass and energy conserving, 350-year simulation with the Community Earth System Model version 2.1 (CESM2.1) bidirectionally coupled to the Community Ice Sheet Model version 2.1 (CISM2.1). In this simulation, the carbon dioxide concentration is initially increasing by 1% per year  from pre-industrial levels (287 ppmv), to a quadrupling (1140 ppmv) and stabilization after year 140. The model simulates a global warming of 5.3 K and 8.5 K with respect to preindustrial by years 131-150 and 331-150, respectively, and a strong decline in the North Atlantic Meridional Overturning Circulation that is initiated before GrIS runoff substantially increases. 91% of the total GrIS contribution to global mean sea level rise (SLR, 1140 mm) is simulated in the two centuries following CO2 stabilization, as the mass loss increases from 2.2 mm SLR per year in 131-150 to 6.6 mm SLR per year in 331-351. This increase is caused by melt acceleration as the ablation areas expand, and Greenland summer surface temperatures predominantly approach melt conditions when the global warming exceeds a certain threshold (around 4.2 K).  This enhances the albedo and turbulent heat fluxes contribution to total melt energy.  
The Food-Environment-Health Nexus of nutrition security in India
Authors: Rulli Maria Cristina , Ricciardi Livia , Chiarelli Davide Danilo , D'Odorico Paolo
Published: March 2020

Feeding humanity while preserving environmental sustainability is one of the major challenges of the next few decades. Many of the global changes for planetary sustainability are due to the food system that is increasing production at the expense of the environment. However, nutrition related diseases caused by low quality diets are on the rise. The 2018 FAO report on  State of Food Security and Nutrition in the World shows that the number of malnourished people keeps increasing.  Undernourished people account for 821 million, including 151 million children under five affected by stunting, while the lives of over 50 million children in the world continue to be threatened by wasting. On the other hand, over 38 million children under five years of age are overweight, 672 million adults are obese, while diabetes, high blood pressure and anaemia are increasing.

Iron Deficiency Anaemia (IDA) is a major problem in India, especially among women. Around 53.1% of Indian women are affected by IDA, which is indeed becoming a major public health issue.

Although India was the first country to launch the National Nutritional Anemia Prevention Program in 1970, IDA remains widespread. There are many reasons for the emergence of a wide range of IDA in India, namely, insufficient iron intake, poor iron absorption, increased iron demand during repeated pregnancy and lactation, insufficient iron reserve at birth, umbilical cord clamping time, and food supplementation.

Punjab is the Indian state facing the most severe condition regarding the prevalence of anaemia, despite this state being one of the main food producers of India. Taking Punjab as a case study we analysed to what extent it is possible to feed the Punjab population with an healthy (adequate in term of micronutrient) and sustainable diet. To this end, using data from National Family Health Survey-4 (NFHS-4) and projected population surveys, an estimation of iron requirement is calculated. Natural resources (i.e. land, water) used for current diet and the additional resources needed to sustainably feed the local population with a reference healthy planetary diet are evaluated.
Kinetic aspects of major and trace elements in olivines from variably cooled basaltic melts
Authors: Lang Sarah , Mollo Silvio , France Lyderic , Nazzari Manuela , Misiti Valeria , Gurenko Andrey A. , Devidal Jean-Luc
Published: March 2020

Olivine is an important mineral phase in naturally cooled basaltic rocks. The texture and composition of olivine are strictly related to the interplay between the degree of magma undercooling and crystal growth rate. Crystals formed at low undercoolings and growth rates generally show polyhedral-hopper textures and quite homogeneous compositions, while skeletal-dendritic textures and evident crystal zonations occur at high undercoolings and growth rates. In this context, we have performed equilibrium and disequilibrium (i.e., cooling rate) experiments to better understand, by a comparatively approach, the effects of crystallization kinetics on the incorporation of major and trace cations in olivine lattice. The experiments were carried out in a 1 atm vertical tube CO-CO2 gas-mixing furnace to perform experiment at atmospheric pressure and oxygen fugacity of QFM-2 using a basaltic glass (i.e., OIB) as starting materials. The equilibrium experiment was performed at 1175 °C. These target temperatures were kept constant for 240 h and then quenched. Conversely, the disequilibrium experiments were performed at the superliquidus temperature of 1250, and 1300 °C, which was kept constant for 2 h before cooling. The final target temperatures of 1150 (undercooling -ΔT = 50 °C), and 1175 °C (-ΔT = 25 °C) were attained by applying cooling rates of 2 °C/h, 20 °C/h, and 60 °C/h. Then the experimental charges were quenched. Results show that the olivine texture shifts from euhedral (i.e., equilibrium) to anhedral (i.e., disequilibrium) under the effect of cooling rate and rapid crystal growth. In equilibrium experiments, the composition of olivine is homogeneous and non chemical gradients are found in the melt next to the crystal surface. In contrast, a diffusive boundary layer develops in the melt surrounding the olivine crystals growing rapidly under the effect of cooling rate and degree of undercooling. The compositional gradient in the melt increases with increasing cooling rate and undercooling, causing the diffusive boundary layer to expand towards the far field melt. Because of the effects of crystallization kinetics, skeletal-dendritic olivines incorporates higher proportions of major and trace elements that are generally incompatible within their crystal lattice under equilibrium conditions.
Spatial soil respiration measurements under varying environmental conditions in a dry grassland
Authors: Balogh János , Fóti Szilvia , Gecse Bernadett , Papp Marianna , Süle Gabriella , de Luca Giulia , Pintér Krisztina , Kardos Levente , Mónok Dávid , Nagy Zoltán
Published: March 2020

Spatial variability of ecosystem processes constitutes significant uncertainty source in greenhouse gas flux measurements and estimations. The major disadvantage of the chamber-based flux measurements is the poor spatial representativeness, but eddy-covariance measurements also have an uncertainty due to the unequal and not constant footprint area. One way to overcome these difficulties is the spatial sampling improving the field-scale data coverage.

The aim of this study was to describe the spatial variability of grassland soil CO2 efflux under varying environmental conditions. For this reason, we conducted spatial measurements on a range of variables including soil respiration, above-ground biomass, greenness index of the vegetation, soil water content and soil temperature during a seven-year study in a dry grassland site in Hungary. Altitude and soil organic carbon (SOC) content of the measuring positions were also used as background factors. Measurements were repeated 19 times at 78 positions during the study, in the main phenological stages of the grassland vegetation: spring growth, summer drought, autumn regrowth. The sampling scheme was based on 80×60 m grid of 10 m resolution. SOC content was highly variable among the positions due to the exposure differences and their environmental constrains. We analyzed the effect of the drivers on soil respiration grouping the measuring positions by the SOC content of the soil.
Boulder deposits on the southeastern coast of Cyprus and their relation with paleotsunami events of the Eastern Mediterranean
Authors: Evelpidou Niki , Zerefos Christos , Synolakis Costas , Repapis Christos , Karkani Anna , Polidorou Miltiadis , Saitis Ioannis
Published: March 2020

Cyprus has a long record of tsunami waves, as noted by archaeological and geological records. Large boulder deposits have been noted in the southeastern and western part of the Island. At Cape Greco (southeastern Cyprus) large boulders have been noted, however, no detailed geomorphological research has taken place so far and the related high energy event remains undated. Our research focuses at Cape Greco Peninsula in order to record in detail and interpret the large boulders deposits. The boulders, located at 3 m amsl, are fragments of a layer of an upper Pleistocene aeolianite, which is overlaying unconformly a lower Pleistocene calcarenite. Dimensions and spatial distribution of 272 small, medium and large boulders were documented, while their precise distance from the coastline was recorded by field mapping and remote sensing, using GNSS, drone and GIS technics. Several large boulders weighting more than ~30 metric tons were found up to 60m inland. Geomorphologic mapping and morphometric measurements, along with the presence of marine organisms suggests that some of the boulders were removed from their original intertidal zone and were transported inland by the force of large waves. In this work, we attempt to determine the extreme event that caused their transport inland. We further attempt a correlation of the event with already known tsunami events from Eastern Mediterranean, based on the estimated wave heights and the radiocarbon dating of marine gastropods (Vermetus sp.).
Antarctic ice dynamics - from deep past to deep future
Authors: Winkelmann Ricarda , Albrecht Torsten , Garbe Julius , Donges Jonathan , Levermann Anders
Published: March 2020

The Antarctic Ice Sheet has undergone extensive retreat and re-advance in its glacial-interglacial history. With progressing anthropogenic climate change, the associated ice dynamics and feedbacks could further lead to persistent and potentially irreversible ice loss from Antarctic drainage basins in the future.

Process-based models, in combination with paleo and modern records, provide the tools to reconstruct the glacial-interglacial history of the Antarctic Ice Sheet, to improve our understanding of the involved processes and critical thresholds, and to better anticipate possible future pathways.

Here we present simulations of the Antarctic Ice Sheet over the past two glacial cycles using the Parallel Ice Sheet Model PISM. As the conditions in particular at the base of the ice sheet are weakly constrained, and proxy data for the climatic forcing over the last glacial cycles is sparse, we assess the sensitivity of the model response with respect to the choice of boundary conditions. We further conduct an ensemble analysis in order to systematically constrain uncertainties with respect to representative model parameters associated with ice dynamics, climatic forcing, basal sliding and bed deformation.

Based on the insights into the dynamic threshold behavior and estimates of the ice sheet’s contributions to global sea-level changes in the past, we investigate the long-term future stability of the Antarctic Ice Sheet under different levels of global warming. We show that the ice sheet exhibits a multitude of temperature thresholds beyond which ice loss into the ocean becomes irreversible. Each of these thresholds gives rise to hysteresis behavior, meaning that the currently observed ice-sheet configuration cannot be regained even if temperatures were to be reversed to their present-day levels.
Palaeoenvironmental expression of humid phases in the western Nefud Desert over the past c. 500,000 years
Authors: Clark-Wilson Richard , Armitage Simon , Candy Ian
Published: March 2020

Orbitally-driven humid phases in arid regions such as the Arabian and Saharan Deserts have played an important biogeographic role in ancient human dispersals, range expansions/contractions and population structure. The timing and regional climatic pattern of humid phases has been shown by multiple long-term continuous palaeoenvironmental records from both marine and terrestrial (speleothems and long palaeolake cores) archives. These attest to episodic humid phases across this region in line with peak interglacial periods over the Pleistocene. However, these records lack detailed information at the scale at which humans interact with the environment, meaning these interactions are poorly understood. To address this, we apply multi-proxy palaeoenvironmental analysis to interdunal carbonate/siliceous sediment beds that formed during episodic humid phases over the past c. 500,000 years in the western Nefud Desert, Saudi Arabia. While such deposits are short relative to many marine, speleothem and palaeolake records, they provide “snapshots” of the palaeoenvironmental conditions experienced by ancient humans. Importantly, these deposits are often directly associated with Lower and Middle Palaeolithic archaeology, demonstrating they were an important locus for ancient human activity during humid phases.

Our analysis demonstrates that humid intervals related to MIS 11, 9, 5e and 5a follow a simple environmental pattern where relatively stable interdunal lake bodies existed through a single humid phase. In contrast, MIS 7 is climatically complex as the sediment record demonstrates a dynamic hydrological system fluctuating between lacustrine and palustrine conditions within a single humid interval. Where available, diatom or invertebrate palaeoecology data consistently indicate predominantly fresh waters across multiple humid intervals, and this is supported by a lack of evaporitic minerals (i.e. gypsum and halite) through all sequences. We therefore argue that the western Nefud Desert has repeatedly provided vital freshwater resources for ancient humans and other fauna over the past c. 500,000 years.