bluuebunny/crossref_metadata_2025 huggingface dataset:
A More Capable Array Infrastructure
Authors: Parker Tim , Hamilton Val , Moores Andrew
Published: March 2021

A more capable infrastructure would enable greater monitoring capabilities. We propose a deeper grouted casing and using borehole best practices to ensure improved coupling and a better environment for reducing site and emplacement noise in both high and low frequencies and specifically the horizontal component recording. Casing emplacements should be a one to two day operation for installation. Stations using the new Trillium T120PH Slim or dual sensor Cascadia Slim in a single cased hole will have wider bandwidth, larger dynamic range, resiliency and low noise recording that would enable new observations along with higher sensitivity for local earthquake recording. Dry cased holes are the standard for long term geophysical observatories and a better investment when all the associated costs of operating observatories are considered. Facilities are both renewing old stations and trying to improve array performance through these new instruments.  This line of Trillium borehole instruments are very robust with low SWaP (Size, Weight and Power), a 300 meter continuous immersion rating and of corrosion resistant construction.  These sensors can be installed in bedding material or with a hole lock and are compatible with the ultimate installation, grouting it in!
Searching for low frequency earthquakes with various durations near Parkfield, California
Authors: Huang Hui , Hawthorne Jessica
Published: March 2021

Previous studies suggest that all LFEs could be roughly the same size; most LFE durations are between 0.2 and 0.5 s, and most LFE moments fall within a 1 to 2-magnitude unit range. These apparently characteristic LFE sizes could imply that LFEs are hosted on asperities of a characteristic size on the plate interface.  However, it is also possible that LFEs with a range of sizes do occur but are not detected. With existing methods, it is usually harder to detect LFEs with shorter or longer durations. In this study, we search for LFEs with various durations near Parkfield, California. We generate synthetic LFE templates with durations  of 0.05 - 1 s by modifying Shelly (2017)’s template waveforms. We cross-correlate time-shifted versions of the templates with 500 days of seismic data to search for LFEs within 5 km of the original template location. We estimate the duration and location of each detection by associating the detection with the template that it matches best. 

Our preliminary results are encouraging. We find large numbers of 0.2-s LFEs at the original location, as have been detected previously, but we also appear to detect LFEs with durations of 0.05 - 1 s. These new detections appear to be spread along 1 3-km region on a near-vertical plane that matches the downward extension of regular seismicity. We are currently cautious in interpreting these results, as it remains possible that all the LFEs occur at the original location with the same duration and that our apparent range of detections simply reflects scatter introduced by noisy data. Nevertheless, we note that our initial analysis implies that LFE duration in Parkfield changes minimally with LFE moment, and we are continuing to more rigorously assess the LFEs’ properties and their implications.
Simultaneous replacement of plagioclase by albite and K-feldspar: natural evidence and hydrothermal experiments
Authors: Nurdiana Astin , Okamoto Atsushi , Uno Masaoki , Tsuchiya Noriyoshi
Published: March 2021

Replacement of feldspars occurs ubiquitously during fluid-rock interaction in crusts, and the formation of micro- to nano- pores along with the replacement potentially provides significant impacts on hydrological properties within the crust (e.g. Plümper et al., 2017; Yuguchi et al., 2019). In this contribution, we report the novel texture of the plagioclase replacement by K-feldspar and albite and showed the conditions of such replacement. The mafic schists near the pegmatitic quartz diorite within the Kinkasan Island, NE Japan show extensive feldspar alteration at various stages, involving Na-rich and K-rich fluids, respectively. Interestingly, during the later K-rich fluid infiltration at 400-570 ˚C at 0.3–0.45 GPa, plagioclase (An35-60) was replaced by K-feldspar (An0Ab1Or99) and albite (An4Ab94Or2) intergrowth, meaning that simultaneous K-feldspathization and albitization, and nano- to microscale pore network developed preferentially along with albite, resulting in an increase of the bulk rock porosity up to 1.34±0.14%.

To understand the relationship between K-feldspar and albite formations within the same plagioclase grain, we conducted the hydrothermal experiments on the feldspar replacement by using different pairs of starting minerals (anorthite, An96Ab4; labradorite, An66Ab33Or1; albite, An1Ab99) and fluid compositions (2M KCl and/or NaCl aqueous solutions) for 4-8 days. AIn all runs, the replacement processes of feldspars developed the distinct reaction front and pores formation close to the reaction front with porosity up to ~7%. In the experiments with KCl solution, the reaction front migrated twice faster than those with the mixture of KCl and NaCl. The most intense replacement occurred in the run of Labradorite-KCl solution, where large cavities were formed in the center of the labradorite grain with developing albite exsolution, and homogenous rim of K-feldspar precipitation. Such occurrences are similar to the replacement texture observed in the mafic schist within the Kinkasan Island and suggest the preferential removal of Ca and the fixed Na during K-feldspar formation. Our experimental results indicate the primary controls of the fluid composition on the replacement texture, pore formation, and the reaction rate.

Keywords feldspar replacement, micropores, fluid transport, hydrothermal experiment, Kinkasan
Development Mechanism of Moraine Debris Flows in Parlung Zangbo Basin, Southeast Tibet, China
Authors: Yang Dongxu , Huang Hai
Published: March 2021

Located in the north of the Great Bend of Yarlung Zangbo River, the Purlung Zangbo basin is the largest distribution area of marine glaciers in China. Here is one of the most serious sections for geological disasters in the Sichuan-Tibet transportation corridor, which poses a serious threat to the planning and construction of the Sichuan-Tibet Railway and Expressway and other important infrastructures. In order to assess the risk of geological disasters along the proposed Sichuan-Tibet Railway, more than 80 typical moraine landslides, glacier collapsed debris flows, and glacial lake breakouts in the basin were selected through remote sensing interpretation and field verification, which were carried out ground investigation and geotechnical properties tests in detail. The main types, material sources and key influencing factors of the moraine geological hazards are analyzed by in-situ tests of large-scale straight shear, double ring penetration, matrix suction, dynamic penetration and indoor sample testing methods such as consolidation compression, triaxial shear, and OSL dating, combined with regional temperature, rainfall, multi-stage remote sensing images and geological mapping data. Finally, the starting mechanism and disaster scale of loose moraine are preliminarily simulated by combining the water and thermal product index method and FLOW 3D numerical analysis software. The results show that the physical and mechanical properties of moraine have good statistical relations with its water content, void ratio and clay content. The natural density and compression modulus are negatively linear related to the void ratio, while the vertical permeability coefficient and the free expansion ratio show a quadratic relationship with clay content, and also the shear strength and compressive strength are binary relationship with void ratio and moisture content. The permeability, consolidation degree and free surface characteristics are the key parameters affecting the stability of moraine slope. Moraine located in three depositional positions (the front of modern glacier tongue, the middle reaches of glacial valley and the bank slope of main river ) has different starting modes, which are "shoveled-scraped and migration type", "erosion and blocking-burst type", and "unloaded and permeated type". When it intersects with the main traffic lines, different countermeasures and application should be adopted: avoidance by bridges or tunnels, slope reinforcement, and cutting or subgrade. 
Thermodynamic Contribution to Lightning Activity in the Fourth Chimney
Authors: Williams Earle , Enore Diego , Mattos Enrique , Wu Yen-Jung Joanne
Published: March 2021

Lightning activity over oceans is normally greatly suppressed in comparison with continents.  The most conspicuous region of enhanced lightning activity over open ocean is found in the equatorial Pacific (150 W) in many global lightning climatologies (OTD, LIS, WWLLN, GLD360, RHESSI, Schumann resonance Q-bursts) and is associated with the South Pacific Convergence Zone (SPCZ).  This oceanic lightning anomaly completes the zonal wavenumber-4 structure of continent-based lightning maxima (with nominal 90-degree longitudinal separation between sources), and so is appropriately named “the fourth chimney”.  This region is now under continuous surveillance by the Geostationary Lightning Mapper (GLM) on the GOES-17 satellite (at 137 W).  This total lightning activity is compared with Convective Available Potential Energy (CAPE) from ERA-5 reanalysis.  These CAPE values are correlated with values extracted from thermodynamic soundings at proximal stations Atuona, Rikitea and Tahiti.  The shape of the regional climatology of CAPE resembles that of the SPCZ and is oblique to the equator.  The total lightning flash rate is positively correlated with CAPE, and lightning locations are found preferentially in regions of elevated CAPE on individual days.  The diurnal variation of total lightning for January exceeds a factor-of-two and shows a phase at odds with the usual behavior of oceanic lightning near continents.
The importance of geology when estimating catchment-scale streamflow characteristics: Application of a new technique for hydrologic similarity and regionalization
Authors: Janssen Joseph , Ameli Ali
Published: March 2021

Expanding the scientific understanding of global hydrological processes is a key research area for hydrologists. Research in this area can allow hydrologists to make better predictions in ungauged basins and catchments under climate change scenarios. Though hydrological processes are largely understood at a laboratory-scale, catchment-scale processes are much more complex and unknown. Previous studies at the catchment-scale have shown catchment geology is largely irrelevant in determining components of streamflow. Laboratory-scale experiments, however, have revealed that this is unlikely. This contradiction indicates the current techniques for determining hydrological variable importance in the literature are insufficient. In this paper, we quantify the influence of the interaction amongst climatic, geological, and topographical features on a large set of hydrological signatures in snow-dominated regions across North America, using Stable Extrapolative Marginal Contribution Feature Importance. The preliminary results show that when we consider interaction effects among climatic and geophysical features, and remove the influence of correlation, geological features show considerable importance at the catchment scale. We contend that this study contributes to the scientific understanding of catchment-scale hydrological processes, especially in cold, ungauged basins.
Volcanic-induced global monsoon drying modulated by diverse El Niño responses
Authors: Paik Seungmok , Min Seung-Ki , Iles Carley E. , Fischer Erich M. , Schurer Andrew P.
Published: March 2021

This study identifies a crucial cause of the large uncertainty in global precipitation response after volcanic eruptions. We find an important contribution of diverse El Niño responses to the inter-simulation spread in the global monsoon drying responses to tropical eruptions. Most Coupled Model Intercomparison Project Phase 5 (CMIP5) models simulate El Niño–like equatorial eastern Pacific warming at the year after eruptions but with different amplitudes, which drive a large spread of summer monsoon weakening and corresponding precipitation reduction. Two factors are further identified for the diverse El Niño responses among CMIP5 model simulations. First, difference in imposed volcanic forcings induces systematic differences in the Maritime Continent precipitation drying and subsequent westerly winds over equatorial western Pacific, accounting for a large portion (29%) of inter-simulation spread in El Niño intensities following eruptions. In addition, the internally generated warm water volume over the equatorial western Pacific in the pre-eruption month also contributes to the diverse El Niño development, explaining about 14% of the total inter-simulation variance through the recharge oscillator mechanism. Our findings based on CMIP5 multi-model simulations confirm that reliable estimates of the volcanic forcing magnitude as well as the pre-eruption oceanic condition are required to obtain more reliable simulations or predictions of the hydrological responses to tropical eruptions.
Spatial and temporal dynamics of monsoon-induced landslides in Nepal in 2020
Authors: Gnyawali Kaushal Raj , Tannant Dwayne D. , Bhattarai Yogesh , Jayana Rijan , Talchabhadel Rocky
Published: March 2021

In the monsoon season, landslides are major disasters in Nepal, causing loss of life and economic impacts. The landslides triggered in the 2020 monsoon (June – September) in Nepal caused more than 300 fatalities and affected about 800 families. A spatial and temporal database of landslides in this region does not exist, which has hindered an understanding of landslide dynamics and the development of a regional early warning system (EWS). In this study, we prepare a time-stamped (hourly) geo-referenced database of the landslides triggered by the 2020 monsoon in Nepal and investigate their dynamic trends. We track landslides from online news for each day during the monsoon to map their location and time. The database contains 332 mapped landslides, out of which accurate time stamps are available for 126 landslides. The spatial pattern shows a large concentration of landslides in central Nepal (districts of Parbat, Kaski, Myagdi, Baglung, Gulmi, and Syangja). The temporal pattern reveals that landslides in this region occur mostly during late night or early morning. We estimate hourly rainfall thresholds for landslide occurrence from the Integrated Multi-satellitE Retrievals for GPM (IMERG) rainfall product. The database and analysis provide a basis for estimating regional rainfall thresholds for Nepal and the design of an EWS.
Lithosphere flexure estimation of an non-uniform flexural rigidity plate：A quantitative modeling approach
Authors: Xu Mingju , Wu Zhaocai , Ji Fei , Ruan Aiguo , Li Chunfeng
Published: March 2021

Lithosphere motion is one of the fundamental processes in Earth tectonics. To understand the processes involving the nature of tectonic evolution and dynamics, it is critical to figure out the lithosphere flexure of tectonic plates. Over long-term (> 105 yr) geological timescales, the lithosphere can be modelled as flexing like a thin, elastic plate, using the partial differential equation for flexure of an orthotropic plate. The partial differential equation is used indirectly to form theoretical admittance and coherence curves, which are then compared against the observed admittance and coherence to invert a non-uniform flexural rigidity (or effective elastic thickness, Te) plate. The non-uniform flexural rigidity lithosphere flexure amplitude can be estimated after that.

In this presentation, we use the classic lithosphere model with applied surface load at ground and internal load at Moho, but assume that the compensation material is denser than the mantle material beneath Moho. The density contrast between compensation material and mantle material beneath Moho is set to be 200 kg/m3 referring to the density contrast of the uppermost and bottom lithosphere mantle. In such a lithosphere model, errors of lithosphere flexure estimation are mainly contributed by the errors of Te and Moho recovering. Synthetic modelling is then performed to analyze the incoming influence deriving from Te and Moho errors.

The synthetic modelling reflects 1) the lithosphere flexure estimation errors are not sensitive to the errors of Te recovering, even an error of about 10 km of Te only result in an error within 1km of lithosphere flexure, 2) the influence of Moho errors to lithosphere flexure errors will be magnified in regions where Te is low, as lithosphere flexure errors over 1km mainly occur in regions where Te is lower than 8km.
Structure and Coalescence of Magnetopause Flux Ropes and Their Dependence on IMF Clock Angle: Three-Dimensional Global Hybrid Simulations
Authors: Guo Jin , Lu San , Lu Quanming , Lin Yu , Wang Xueyi , Huang Kai , Wang Rongsheng , Wang Shui
Published: March 2021

Flux ropes are ubiquitous at Earth’s magnetopause and play important roles in energy transport between the solar wind and Earth’s magnetosphere. In this paper, structure and coalescence of the magnetopause flux ropes formed by multiple X line reconnection in cases with different southward interplanetary magnetic field (IMF) clock angles are investigated by using three-dimensional global hybrid simulations. As the IMF clock angle decreases from 180°, the axial direction of the flux ropes becomes tilted relative to the equatorial plane, the length of the flux ropes gradually increases, and core field within flux ropes is formed by the increase in the guide field. The flux ropes are formed mostly near the subsolar point and then move poleward towards cusps. The flux ropes can eventually enter the cusps, during which their helical structure collapses, their core field weakens gradually, and their axial length decreases. When the IMF clock angle is large (i.e., the IMF is predominantly southward), the flux ropes can coalesce and form new ones with larger diameter. The coalescence between flux ropes can occur both near the subsolar point when they are newly formed and away from the subsolar point (e.g., in the southern hemisphere) when they move towards cusps. However, when the IMF clock angle is small (≤ 135° ), we do not find coalescence between flux ropes.
Individual Sick Fir Tree (Abies mariesii) Identification in Insect Infested Forests by Means of UAV Images and Deep Learning 
Authors: Nguyen Ha Trang , Lopez Caceres Maximo Larry , Moritake Koma , Kentsch Sarah , Shu Hase , Diez Yago
Published: March 2021

Insect outbreaks are a recurrent natural phenomenon in forest ecosystems expected to increase due to climate change. Recent advances in Unmanned Aerial Vehicles (UAV) and Deep Learning (DL) Networks provide us with tools to monitor them. In this study we used nine orthomosaics and normalized Digital Surface Models (nDSM) to detect and classify healthy and sick Maries fir trees as well as deciduous trees. This study aims at automatically classifying treetops by means of a novel computer vision treetops detection algorithm and the adaptation of existing DL architectures. Considering detection alone, the accuracy results showed 85.70% success. In terms of detection and classification, we were able to detect/classify correctly 78.59% of all tree classes (39.64% for sick fir). However, with data augmentation, detection/classification percentage of the sick fir class rose to 73.01% at the cost of the result accuracy of all tree classes that dropped 63.57%. The implementation of UAV, computer vision and DL techniques contribute to the development of a new approach to evaluate the impact of insect outbreaks in forest.
Freshwater input into a low-Arctic Fjord in West Greenland: Timing, drivers and model evaluation
Authors: Abermann Jakob , Langley Kirsty , Myreng Sille , Petersen Dorthe , Rasmussen Kerstin , Peßenteiner Stefanie
Published: March 2021

The majority of the freshwater input from Greenland stems from the Greenland Ice Sheet. Despite its importance in terms of freshwater totals, there is a much higher number of individual catchments disconnected from the ice sheet contributing on average about 26% of the total Greenland freshwater flux. Most of those catchments have local glacier cover, only very few of them are instrumented and little scientific literature exists. We present a dataset of 12 years of discharge of four catchments less than 15 km apart, that are different in size (between 7 and 32 km²), local glacier coverage (4-11%) and lake cover (0-5%). They all drain into Kobbefjord, a well-studied fjord in West Greenland, near Greenland’s capital Nuuk. We find that annual specific discharge totals vary greatly (between 1.2 and 1.9 m/yr on a 12-year average within 15 km) due to a general climatic gradient and different strengths of orographic shading. The seasonal cycle differs among the sites mainly due to different exposure to solar radiation as a driver for major snowmelt; small ice coverage in the catchments plays only a minor role in discharge variability. Dry years generally increase the magnitude of spatial gradients in specific discharge and no significant temporal trends have been found in the studied catchments. On the sub-daily scale, the presence and elevation of lakes determines the catchment’s response during sunny days, leading to a difference in the timing of maximum discharge of between 7 and 12 hours depending on the site and the time of the year. The response of discharge to major precipitation events is discussed, where uniform reaction is found for the catchments with no lakes near the gauge and a delay of between 5 and 7 hours in the catchment with low-lying lakes. A comparison with a recently published modelled discharge time series on individual catchment scale shows the model’s capability of reproducing both snowmelt and large-scale storm events; however, the strong spatial heterogeneity of discharge magnitude and timing as well as the presence and variability of base-flow is not captured. We discuss methods to combine observational data with existing model output in order to improve the potential of their combined usage on the Greenland-scale.
Determinant factors in olive oil accumulation for optimizing harvest time in a context of climate change
Authors: Cabezas José M. , Muñoz Estrella , De la Rosa Raúl , León Lorenzo , Lorite Ignacio J.
Published: March 2021

Olive is a woody crop extended over 10 Mha around the world (FAOSTAT, 2019), being Spain the country with the largest area (2.7 Mha). Andalusia is located in the South of Spain, with 1.6 Mha cultivated with olive trees, most of them (around 90%) dedicated to olive oil production (MAPA, 2020). This region is characterized by a great diversity of weather conditions. This diversity greatly affects important agronomic parameters of olive as the pattern of oil accumulation. This influence is different depending on the cultivar considered. In addition, this pattern of oil accumulation is a key aspect since is the most relevant trait determining the optimal harvest time. For that reason, in the present study, the relative influence of cultivar and environment, and their interaction, have been evaluated for the full pattern of oil accumulation.

This study was carried out in four locations of Andalusia covering a wide range of weather conditions, and where olive trees are well established or under expansion: Antequera (Málaga), Córdoba, Úbeda (Jaén) and Gibraleón (Huelva). In 2008, five cultivars were planted in a randomized complete block design consisting in four blocks and four trees per elementary plot: Arbequina, Hojiblanca, Koroneiki, Picual and Sikitita-3 (a new registered cultivar from the olive breeding program developed by the University of Córdoba and IFAPA). The first two locations were monitored in 2018 and 2020 while the other two locations were monitored only during 2020 campaign. Fruits samples were collected periodically, starting 4 weeks after full bloom until the oil accumulation was finished. Then, in the laboratory, fruits’ oil content was measured by nuclear magnetic resonance.

Results show sigmoid patterns regarding fruit oil accumulation and dry basis along each campaign in all genotypes, locations and years. There were significant differences of maximum olive oil accumulation among genotypes, recording the genotype Sikitita-3 the maximum ones. Furthermore, a significant genotype-environment interaction was also found for these. These results have relevant consequences regarding the selection of the optimal harvest time, to accomplish a desired balance between maximum oil accumulation and quality indicators which require early harvest dates.

 

References:

FAOSTAT, 2019. Food and Agriculture Organization of the United Nations. FAOSTAT database available at http://www.fao.org/faostat/en/#data. Last accessed 12 January 2020.

MAPA, 2020. Ministry of Agriculture, Fisheries and Food. Survey of surfaces and crop yields 2020 available at https://www.mapa.gob.es/es/estadistica/temas/estadisticas-agrarias/agricultura/esyrce/. Last accessed 12 January 2020.
Bring the noise: Piecing together a discharge record from an automated salt dilution gauging setup and various other information sources
Authors: Weijs Steven , Eugeni Sophia
Published: March 2021

Streamflow measurement and prediction are important for proper water resources management. In this case, the water resources problem is drought in the Coastal Mountains of British Columbia, Canada, where a village is drawing drinking water from a mountain stream. Because of challenges with other flow measurement methods in streep turbulent streams, salt dilution gauging is the best way to measure streamflow, but it is labour intensive.

To advance progress towards the singularity, an intelligent automated salt dilution gauging system was deployed, and provides good results, but some disturbances occur due to the presence of a tributary and a drinking water intake. We show how this noise can be turned into signals and discuss a range of other signals that together provide input for the discharge record.
Power Anisotropy, Dispersion Signature and Diffusion Region in the 3D Wavenumber Domain of Space Plasma Turbulence
Authors: Lin Rong , He Jiansen , Zhu Xingyu , Zhang Lei , Duan Die , Sahraoui Fouad , Verscharen Daniel
Published: March 2021

We explore the multi-faceted important features of turbulence (e.g., anisotropy, dispersion, diffusion) in the three-dimensional (3D) wavenumber domain (k, kperp1, kperp2), by employing the k-filtering technique to the high-quality measurements of fields and plasmas from multi-spacecraft constellation (i.e., MMS). We compute the 3D power spectral densities (PSDs) of magnetic and electric fluctuations (marked as PSD(δB(k)) and PSD(δE′‹vi›(k))), both of which show prominent spectral anisotropy in the sub-ion range. We calculate the ratio between PSD(δE′‹vi›(k)) and PSD(δB(k)), the distribution of which is related with nonlinear dispersion relation. We also compute the ratio between electric spectra in different frames of ion flow, that is PSD(δE′local vi)/PSD(δE′‹vi›), to demonstrate the turbulence ion diffusion region (T- IDR) in the wavenumber space. The T-IDR has an anisotropy and a preferential direction of wavevectors, which is generally consistent with the plasma wave theory prediction based on the dominance of kinetic Alfvén wave (KAW). This work manifests the worth of the k-filtering technique in diagnosing turbulence comprehensively, especially when the electric field is involved.
Ocean Circulation from the synergy of altimeter-derived and oceanic tracers observations
Authors: Ciani Daniele , Rio Marie-Hélène , Buongiorno Nardelli Bruno , Guinehut Stéphanie , Charles Elodie , Etienne Hélène , Santoleri Rosalia
Published: March 2021

Measuring the ocean surface currents at high spatio-temporal resolutions is crucial for scientific and socio-economic applications. Since the early 1990s, the synoptic and global-scale monitoring of the ocean surface currents has been provided by constellations of Radar Altimeters. The Altimeter observations enable to derive the geostrophic component of the surface currents with effective spatial-temporal resolutions O(100 km) and O(10 days), respectively. Therefore, only the largest mesoscale oceanic features can be accurately resolved. In order to enhance the altimeter system capabilities, we propose a synergistic use of high resolution, satellite-derived Sea Surface Temperature (SST), Chlorophyll concentrations (Chl) and Altimeter-derived currents. Our approach is tested in both global-scale and regional contexts.
At global scale, relying on past numerical studies, we perform a sensitivity experiment based on several gap-free SST datasets, emphasizing strengths and weaknesses in ocean currents applications. Overall, the comparison with in-situ measured currents shows that our synergistic method can improve the altimeter estimates up to 30% locally.
Then, our method is also implemented with Chl data in the  Mediterranean Sea, where the most energetic variable signals are found at spatio-temporal scales up to 10 km and few days. We test the method feasibility in an Observing System Simulation Experiment relying on model outputs of the European Copernicus Marine Service. Statistical analyses based on the 2017 daily data show that our approach can improve the altimeter-derived currents accuracy up to 50% at the basin scale, also enhancing the effective spatial-temporal resolutions up to 30 km and less than 10 days, respectively. The method efficiency decreases when the surface Chl patterns are dominated by the biological activity rather than the currents advection, which mostly occurs in the mid-February to mid-March time window. Preliminary tests on the method applicability to satellite-derived data are also presented and discussed.
Mapping resilience to natural hazards in urban systems: the case study of Ischia Island (southern Italy) 
Authors: Petrosino Paola , Alberico Ines
Published: March 2021

The dissemination of resilience concept to citizens, politicians, entrepreneurs, territorial planners is the first and most important step to shelter urbanized areas from natural hazards.

In this frame we propose a procedure to draw resilience maps as tools to facilitate the communication of inherent resilience status of cities. The core of the research is the assessment of this status for the environmental component that deeply influences the livability and development of urban systems. The procedure, implemented in a Geographic Information System framework named “Resilience and Disaster Risk Management”, defines and maps indices and indicators at the census district scale. It considers the different nature of data (attribute data, urban system components represented with primitive features, polygon, line and point) and for each of them indicates the necessary steps to draw the resilience indicator maps.  Through their ranking into the same number of classes, the procedure makes the indicators fully comparable to each other and allows the definition of indices as aggregation of indicators.

The procedure was tested at Ischia Island (Southern Italy) exposed to volcanic, seismic, landslide, flood and coastal erosion hazards. The spatial variability of environmental resilience is shown into several maps that discretize the island into high, medium and low resilience classes.

From our analysis emerged that the historic centers of the towns, in general show the lower resilience, mostly due to poor quality and age of buildings. The lack of building surplus acts negatively on resilience making it difficult to redraw the urban structure during the preparedness phases, when several interventions could be carried out with the aim of lowering the number of people to put in safe from a possible disaster. Our analysis brought also to the consideration that the distribution of green areas on the island results unable to counterbalance the negative effects of urbanization and enhance the environmental resilience. In as much, no official program of fruition of green areas currently involves Ischia Island, although many geovolcanological and naturalistic valuables would deserve promotion and conservation, contributing to enhance the capability of the territory to cope with adverse events.

The mapping procedure can be applied to larger areas at risk keeping the censual districts as the minimum territorial reference units or using municipal, regional or national administrative units. The expected integration of resilience assessment in territorial planning (e.g. Regional Territorial Plan, Provincial Territorial Plan, and Municipality Territorial Plan) could greatly benefit from the outcomes of the present research for overcoming sectoral approaches in territorial management.
Effects of air pollution on neurodegenerative diseases (Alzheimer's disease and vascular dementia) over Europe for present and future climate change scenarios
Authors: Jiménez-Guerrero Pedro , Guzmán Patricia , Tarín-Carrasco Patricia , Morales-Suarez-Varela María
Published: March 2021

Air pollution has a serious impact on health and this problem will be aggravated under the action of climate change. This climate penalty can play an important role when trying to assess future impacts of air pollution on several pathologies. Among these diseases, the scientific literature is scarce when referring to the influence of atmospheric pollutants on neurodegenerative diseases for future climate change scenarios. Under this framework, this contribution evaluates the incidence of dementia (Alzheimer's disease and vascular dementia) occurring in Europe due to exposure of air pollution (essentially NO2 and PM2.5) for the present climatic period (1991-2010) and for a future climate change scenario (RCP8.5, 2031-2050). The GEMM methodology has been applied to climatic air pollution simulations using the chemistry/climate regional model WRF-Chem. Present population data were obtained from NASA's Center for Socioeconomic Data and Applications (SEDAC); while future population projections for the year 2050 were derived from the United Nations (UN) Department of Economic and Social Affairs-Population Dynamics.

Overall, the estimated incidence of Alzheimer's disease and vascular dementia associated to air pollution over Europe is 498,000 [95% confidence interval (95% CI) 348,600-647,400] and 314,000 (95% CI 257,500-401,900) new cases per year, respectively. An important increase in the future incidence is projected (around 72% for both types of dementia) when considering the effect of climate change together with the foreseen changes in the dynamics of population (expected aging of European population). The climate penalty has a limited effect on the total changes of Alzheimer's disease and vascular dementia (approx. 0.5%), since the large increase in new annual cases over southern Europe is offset by the decrease of the incidence associated to these pathologies over more northern countries, favored by an improvement of air pollution caused by the projected enhancement of rainfall.
Lithosphere-asthenosphere decoupling in the Central/Eastern Alps from seismic anisotropy beneath the dense SWATH-D network
Authors: Link Frederik , Rümpker Georg
Published: March 2021

The Alpine orogeny is characterized by tectonic sequences of subduction and collision accompanied by break-off events and possibly preceded by a flip of subduction polarity. The tectonic evolution of the transition to the Eastern Alps has thus been under debate. The dense Swath-D seismic network as complementary experiment to the AlpArray network provides unprecedented lateral resolution to address this open discussion. We analyze shear wave splitting of this data set to get insights into the deformation at depth by studying seismic anisotropy. Previous studies indicate two-layer anisotropy in the Eastern Alps. This is supported by azimuthal pattern of the measured fast axis direction across all stations of the network. The temporary character of the deployment requires a joint analysis of multiple stations to increase the number of events adding complementary information of the anisotropic property of the mantle. We perform a cluster analysis based on a correlation of the remaining transverse energy between all stations. The energy tensor is calculated in the grid search for the best fitting two-layer splitting parameters to the ensemble of events at each station. This leads to two main groups of different two-layer properties separated at 12.5 degrees Longitude. We identify a layer with constant fast axis direction of 60° over the whole area, with a possible dip from West to East. The lower layer in the West shows N-S direction and upper layer in the East 115° alignment. We propose two likely scenarios, both accompanied by a slab break-off in the Eastern part. The continuous layer can either be interpreted as frozen-in anisotropy with lithospheric origin or an asthenospheric flow evading the retreat of the European slab that would precede the break-off event.  In both scenarios the upper layer in the East is result of a channel flow through the gap formed in the slab break-off. The N-S direction is interpreted as asthenospheric flow mainly driven by the subduction of the European plate below Adria.
On the Potential of Multi-Parametric Measurements for Earthquake Precursors Analysis
Authors: Skorokhod Tetiana , Inbar Nimrod , Reuveni Yuval
Published: March 2021

Despite the existence of a large number of observational data and physical models describing the preparation, performance and consequences of Earthquakes (EQ) events, scientists still do not know much about this physical phenomena. A vast amount of efforts and financial means have already been invested in searching for possible precursors of geodynamic and EQ events, which might be considered disproportionate to the progress already achieved. Nevertheless, this important task deserves further investigation, as any encouraging obtained result will pay off all efforts.

Here, we propose to investigate a multi-parametric integrated approach, augmented by observation from a wide set of possible/potential EQ manifestations in the Lithosphere, Troposphere and Ionosphere. To better tackle the problem of possible EQ precursor detection, four EQ events with magnitudes of 3.9–4.4 M, which occurred in Lake Kinneret pull-apart basin, Israel from the period of May 1 to September 30, 2018, were examined. The multi-parametric observation were simultaneously collected from several stations within a 100 km radius from the studied EQ epicenters. Thus, the following parameters which were investigated are: gamma-ray emissions both from the subsurface and atmosphere, precipitation, atmospheric temperature and pressure, groundwater level and electrical conductivity measured in two wells, precipitable water vapor (PWV) in the atmosphere extracted from GNSS tropospheric path delays, Total Electron Content (TEC) in the ionosphere extracted from GNSS ionospheric path delays. In addition, geomagnetic and solar parameters such as A- and Kp-indices, 10.7 cm radio flux and sun spot number (SSN), were used to exclude the influence of solar-terrestrial coupling and mitigate false positive signatures.

Preliminary results indicate anomalous signals (exceeding 2σ) at all stations for most of the measured parameters, approximately one month before the studied EQ events. Five significant anomalies, lasting 4-7 days, observed in sub-surface gamma-ray emissions were chosen as reference main precursors. Two of those anomalies (35±2 days and 26±2 days before the EQ events) were accompanied by signal enhancements, measured at other stations located several tens of kilometers apart, in PWV, TEC, groundwater electrical conductivity, Rn and CO2. Another two sub-surface gamma-ray anomalies were correlated with precipitation events, while the last observed anomaly (11±3 days before the EQ events), which is the weakest among the five, was not accompanied by any enhanced measured parameter. According to these results, the multi-parametric approach seems to provide a powerful analysis tool used to differentiate between signals originated from geodynamic and other sources. It is suggested that future research can benefit tremendously from vast multi-parametric continuous data collection and analysis.
Calibrating a semi-distributed hydrological model on Fella river basin (Italian Alps)
Authors: Zoratti Veronica , Arnone Elisa , Formetta Giuseppe , Bosa Silvia , Petti Marco
Published: March 2021

The Northeastern Italy and the therein Friuli Venezia Giulia (FVG) region are frequently hit by heavy and prolonged precipitations, which cause frequent debris flow and diffused shallow landslides. In this study we focus on a mountain sub-basin of the Fella river watershed, the Uque at Ugovizza, located in the northeastern Julian Alps of the FVG, where a disruptive rainfall-triggered debris flow occurred in 2003.

The work aims at pursuing two main targets: (i) implementing a rainfall-runoff and hydro-morphodynamical framework for the analysis of debris flow initiated by intense heavy precipitation; ii) exploiting, for the first time, the flexibility of the GEOframe-NewAge semi-distributed hydrological model simulating high temporal resolution simulations (5-minutes) rainfall-runoff events.

The GEOframe-NewAge is an open-source component-based modeling framework, which simulates the entire hydrological cycle of the study area, including the snow melting, the soil water storage and the runoff production and routing in the river network; the model is suitable for the rainfall-runoff event scale simulations in Alpine environment with scarce measurements.

Specifically, we describe the results of the calibration and validation procedures applied to four selected intense events occurred in the period 2009-2019. Meteorological data at 5 minutes-step are used to rainfall-runoff modeling, whereas streamflow at 30 minutes is used for the model calibration and validation. Preliminary results show that the models is able to capture the temporal and spatial dynamic of extremes short events, providing satisfying Nash and Sutcliffe coefficient values.
Temporal disaggregation of daily rainfall data in SuDS design: a case study in Tuscany
Authors: Pampaloni Matteo , Sordo Ward Alvaro , Bianucci Paola , Gabriel Martin Ivan , Garrote Luis , Caporali Enrica
Published: March 2021

Sustainable urban Drainage Systems (SuDS), by themselves or combined with grey traditional infrastructures, help to diminish the runoff volume and peak flow, as well as to improve the water quality. Hydrological design of SuDS is usually based on rainfall volumetric percentiles as the number of rainfall events, Nx, or the accumulated volume of the rainfall series, Vx, to be managed. Sub-index x refers to common qualities used in SuDS design, like 80, 85, 90 and 95%. Usually, only daily rainfall data are available. Nevertheless, due to the characteristics of the urban watershed involved in the SuDS implementation, the quantification of design parameters for these facilities needs sub-hourly rainfall time series. To overcome this issue, a temporal disaggregation methodology was proposed based on the use of a stochastic rainfall generator model (RainSim V3). We analysed the case of Florence University rain gauge (Tuscany, Italy), by collecting 20 years (in the period from 1998 to 2018) of observed data at 15 minutes time step. First, we verified the ability of RainSim model to reproduce observed rainfall patterns at 15 minutes time-step. The parameters of the stochastic model were estimated using observed data with 24 hours time-step. We generated 100 series of 20 years each with a time step of 15 minutes. We accounted two variables to implement the storm events extraction: a) the Minimum Inter-event Time (MIT) between storm events; 2) the storm volume threshold. We obtained a better characterization of the rainfall regime by applying the temporal disaggregation methodology than using daily-observed data. Second, we compared the SuDS design parameters Nx and Vx, obtained by using the stochastically generated rainfall, the observed daily and 15 minutes data. Moreover, the effect of different MITs and different thresholds on Nx and Vx were evaluated. In all the cases, results show that Nx and Vx obtained with the median of the simulated series were closer to the actual observed parameters based on 15 minutes time step than the ones calculated with the observed daily data. Therefore, the proposed temporal disaggregation method arises as an efficient technique to overcome the lack of sub-hourly rainfall data, necessary to adequately design SuDS.
Strain Analysis of Transfer Faults in Extending Regions: Inferences from Micropolar Theory
Authors: Tokay Bülent , Bozkurt Erdin
Published: March 2021

Transfer faults are generally identified as transversely oriented discrete faults linking normal fault segments in extensional tectonic settings.  The presence of the transfer faults in fault networks provides displacement transfer between the normal faults. The role and tectonic significance of transfer faults in overall extensional deformation of the upper crust is however not known very well. Micropolar theory extended by J-2 plasticity facilitates evaluation of a deforming medium in which cataclastic flow takes place with respect to each component of deformation. In this study, a series of experiments based on the Micropolar theory are performed, using fault-slip patterns, to better understand interplay among dip angle of normal and transfer faults connecting to each other, angle of linkage, and extensional direction. Synthetic linkage cases are created systematically considering various orientation of both faults sharing common stretching direction.
Our findings reveal that in orthogonal and oblique linkage cases, 3D strain field is mostly observed; a few cases exhibit plane strain. All cases are subjected to simple shearing. In cases of orthogonal linkage, extensional direction is predominantly oblique to the strike of the normal faults. Many of these cases have no block rotation (microrotation) independent from macrorotation. No particular relationship between changing dip amount of faults and direction of extension is observed. In cases of oblique linkage, (sub)orthogonal direction of extension appear in nearly half of experiments, especially those including normal faults dipping less than 60˚. The frequency of non-zero microrotation is seen apparently more than that in orthogonal linkage cases.
The study represents that structural togetherness of the transfer and normal faults essentially can accommodate complete micropolar strain in a region. This further suggests that not only the normal faults but the transfer faults should also be considered as major primary structural elements in extending domains.