bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbonate System and Acidification of the Adriatic Sea
Authors: Turk Valentina , Bednarsek Nina , Faganeli Jadran , Gasparovic Blaženka , Giani Michele , Guerra Roberta , Kovac Nives , Malej Alenka , Krajnc Bor , Melaku Canu Donata , Ogrinc Nives
Published: March 2020

Although the marginal seas represent only 7% of the total ocean area, the CO2 fluxes are intensive and important for the carbon budget, exposing to an intense process of anthropogenic ocean acidification (OA). A decline in pH, especially in the estuarine waters, results also from the eutrophication-induced acidification. The Adriatic Sea is currently a CO2 sink with an annual flux of approximately -1.2 to -3 mol C m-2 yr-1 which is twice as low compared to the net sink rates in the NW Mediterranean (-4 to -5 mol C m-2 yr-1). Based on the comparison of two winter cruises carried out in in the 25-year interval between 1983 and 2008, acidification rate of 0.003 pHT units yr−1 was estimated in the northern Adriatic which is similar to the Mediterranean open waters (with recent estimations of −0.0028 ± 0.0003 units pHT yr−1) and the surface coastal waters (-0.003 ± 0.001 and -0.0044 ± 0.00006 pHT units yr−1). The computed Revelle factor for the Adriatic Sea, with the value of about 10, indicates that the buffer capacity is rather high and that the waters should not be particularly exposed to acidification. Total alkalinity (TA) in the Adriatic (2.6-2.7 mM) is in the upper range of TA measured in the Mediterranean Sea because riverine inputs transport carbonates dissolved from the Alpine dolomites and karstic watersheds. The Adriatic Sea is the second sub-basin (319 Gmol yr-1), following the Aegean Sea (which receives the TA contribution from the Black Sea), that contribute to the riverine TA discharges into the Mediterranean Sea. About 60% of the TA inflow into the Adriatic Sea is attributed to the Po river discharge with TA of ~3 mM and TA decreases with increasing salinity. Saturation state indicates that the waters of the Adriatic are supersaturated with respect to calcite (ΩCa) and aragonite (ΩAr) throughout the year. However, saturation states are considerably lower in the bottom water layers, due to the prevalence of benthic remineralization processes in the stratification period. The seasonal changes of the chemical and environmental conditions and relatively small size of the Adriatic Sea area the microbial community composition, function (growth, enzymatic activity) and carbon and nitrogen biogeochemical cycles. Significant effects on calcifying organisms and phytoplankton are expected while the effects of possible OA on microbially-driven processes are not known yet.
The impact of inter-annual variability on the surface mass balance of Greenland
Authors: Zolles Tobias , Born Andreas
Published: March 2020

Surface mass balance models that are run over longer timescales are commonly forced with climatological forcing, disregarding natural climate variability. Here we investigate the impact of inter-annual variability of the present day climate using the energy balance model BESSI. The model is forced with daily data of precipitation, temperature, long and short wave radiation and humidity. We create synthetic time series of realistic climate forcing with different time scales of variability by re-ordering the years of present day reanalysis as well as using the climatology.

We find that the model significantly overestimates the Greenland SMB in case of climatological forcing when compared to the original daily reanalysis (40%). The effect of changing inter-annual variability by the re-ordering of forcing years has a relatively minor effect on the Greenland-wide mass balance (<5%), but is more important around the equilibrium line where positive feedback increase its impact over time. The averaging of precipitation is the key factor. It leads to a surface albedo increase as the nature of snowfall changes from event-based to continuous. To reduce this effect we use monthly climatologies in combination with a sub-monthly variability instead of daily climatologies, to retain the event (storm) based nature of precipitation.

Finally, we characterize the errors in cases of using climatology where interannual variability is unknown, such as simulations of the deep past and future and propose a solution.
Using Geo-myths in a classroom: towards creative science writing for scholars
Authors: Lanza Tiziana
Published: March 2020

Since when together with A. Negrete we theorized the efficaciousness of using geo-myths in a classroom for Earth education purposes (Lanza&Negrete 2007) I have been experimenting the use of them in different science narratives context. In my presentation, I will retrace all the experiences done starting with science theatre, including  Open Air museum, till the more recent  done with scholars of secondary schools for re-writing myths and transforming them in fairy-tales for primary school children. Using geo-myths with students in different context has convinced me of their efficaciousness in spreading the knowledge of the planet, while educating to the respect of the Earth. In my presentation I will give also some precious hints in this sense.
Culture and Release of Eastern Brook Trout (Salvelinus fontinalis) in Catharpin Creek, Prince William County, Virginia
Authors: Pilipski Jacob , Smith Albert
Published: March 2020

 In 2014 a project of study began with the students from James Madison High School in Fairfax Virginia U.S.A, participating in Trout Out of the Classroom. The program is designed to have high school students grow, raise and release Brook Trout (Salvelinus fontinalis).  Sustainable brook trout populations require pristine, stable conditions with water temperatures between 1oC-22oC and pH 5.0-7.5. (Eastern Brook Trout Joint Venture) With only 9% of areas that historically supported brook trout along the U.S. eastern seaboard still intact, it is essential successful breading and release programs to be in place (Eastern Brook Trout Joint Venture).

James Madison High’s initial stocking of 50 fingerlings into Catharpin Creek in Haymarket Virginia. This stream is in a protected state-owned area, which was once a vacation resort in the early 1900’s but has been abandoned since a dam break in the 1930s. This site served a dual purpose for the work as both a possible viable ecosystem for the trout, since the stream initial test, using the Smith-Sklarew (2012) index that, among other factors, employs multivariate discriminant analysis to determine a numerical value between 0 and 100. This value "grades" the stream like one would grade a test. Composed of five main metrics - riffle run quality, dissolved oxygen, percent agriculture, distance to nearest road, and water temperature, this model is known as the Brook Trout Sustainability Index, or BKTI. Catharpin Creek rated an index score of 87.5. This score was a bit low (90 and above indicating pristine conditions) but with extensive tree canopy cover in the preserve and cool temperatures, it was chosen as a release site given the potential for improving conditions within the small watershed and the promise of very little future disturbance in the legally protected area. 

Following the initial release in May 2017, one site survey the following December found 5 out of the 50 fingerlings had endured the heat of the summer, suggesting there was sufficient cold water within the system.  With the positive results other Fairfax County high schools (West Springfield and W.T. Woodson).

The student’s process was recognized by Trout Unlimited, The American Fisheries Society and the Izaak Walton League. All three organizations formed a charter, the TIA Alliance, in an effort to replicate the process pioneered by James Madison high teens.  The original index was created for brook trout but, in theory, the process could be molded for any species (plant or animal) at any location.
Internal variability in regional climate simulations
Authors: de Vries Hylke , Lenderink Geert
Published: March 2020

Following the huge increase in computer power over the past fifty years, it is now possible to conduct regional climate simulations at the convective-permitting (CP) scale (horizontal grid spacing O(1-3km)). Societal relevance is evident, as a large fraction of high-impact weather operates on these scales (e.g., intense summer convection, extreme wind gusts, hail storms) and it is only partly known how these processes change as the planet warms. However, because the computational demands of running a CP regional climate model (CP-RCM) are formidable, most CP-RCM simulations to date are relatively short (O(10) years), with future trends being derived as differences between two time slices. Consequently, internal variability is considerable in these decadal simulations for most variables, but is difficult to estimate, especially for the extremes. Nevertheless, these simulations are the best we have at the moment. 

For some variables such as summer rainfall, spatial pooling might be a way to increase the sample size. However we believe a careful analysis of the internal variability is still necessary to provide a context for the future changes. Here we examine different methods to estimate the amplitude of the internal variability of precipitation and temperature over Europe. Special focus will be on comparing the differences between such estimates obtained from O(10) years time-slice experiments and those obtained from long transient RCM simulations (which in contrast to the CP-RCMs are available!), with the expectation that some of the lessons learned in the "RCM-world" carry over to that of the CP-RCM.
Wind effects on the spatial distribution of snow and seasonal water balance in two Mediterranean basins
Authors: Pinto Escobar Fabiola , Mendoza Pablo A. , Shaw Thomas E. , Revuelto Jesús , Musselman Keith , McPhee James
Published: March 2020

Snow water equivalent is highly heterogeneous due to the spatial distribution of precipitation, local topographic characteristics, effects of vegetation, and wind. In particular, the latter has important effects on such distribution, controlling the preferential deposition of snowfall, transport (either by saltation or suspension) on the ground, and sublimation of blowing snow. In this work, we analyze the effects of incorporating redistribution by wind transport when modeling the seasonal water balance in two experimental catchments: (i) the Izas catchment (0.33 km²), located in the Spanish Pyrenees, with an elevation range of 2000-2300 m a.s.l., and (ii) Las Bayas catchment (2.45 km²), located in the extratropical Andes Cordillera (Chile) and elevation between 3400 and 3900 m a.s.l. After assessing model simulations using time series of snow depth and terrestrial lidar scans, we examine the water balance at the annual and seasonal scales, quantifying the different fluxes that govern snow accumulation and melting with a spatially distributed model that considers the physics of transport and the sublimation of blowing snow. Moreover, we characterize the sensitivity of dominant processes to changes in precipitation and temperature. The results of this investigation have important implications on current and future research, allowing to contrast wind effects in the spatio-temporal patterns of accumulation and melting in alpine and subalpine areas, identifying those processes that will be most affected under projected climatic conditions.
Landslides and tsunami generation in large-scale flume experiments and numerical particle-following simulations
Authors: Mulligan Ryan , Franci Alessandro , Celigueta Miguel , Take W. Andy
Published: March 2020

Tsunamis generated by highly mobile slides in large-scale flume experiments are simulated with a numerical model called the Particle Finite Element Method (PFEM). The numerical technique combines a Lagrangian finite element solution with an efficient remeshing algorithm, and is capable of accurately tracking the evolving fluid free-surface and velocity distribution in highly unsteady flows. The slide material is water, which represents an avalanche or debris flow with high mobility, and the reservoir depth is varied, thereby achieving a range of different near-field wave conditions from breaking waves to near-solitary waves. Experimental observations of fluid velocity and water surface levels are obtained using high-speed digital cameras, acoustic sensors and capacitance wave probes, and the data are used to analyze the accuracy of the PFEM predictions. The numerical model shows the capability of holistically reproducing the entire problem from landslide motion, to impact with water, to wave generation and propagation. Very good agreement with the experimental observations are obtained, in terms of landslide velocity and thickness, wave time series, maximum wave amplitude, wave speed and wave shape. The results demonstrate the potential of this numerical method for simulating mass flows, impacts with water, and the tsunamis generation process.
Seismic models of the Los Humeros caldera (Mexico) using the GEMEX project data
Authors: Calò Marco , Figureoa Soto Angel , Cruz-Hernandez Stephani , Granados Chavarría Ivan , De la Rosa Brenda , Angulo Carrilo Joel , Toledo Tania , Gaucher Emmanuel , Jousset Philippe
Published: March 2020

In the framework of the GEMEX project (cooperation between Europe and Mexico for geothermal development), a dense network of 45 stations was deployed in 2017-2018 in the Los Humeros caldera, Mexico.

Thanks to this network an intense local seismic activity has been recorded in the geothermal field and surroundings, from which it has been possible to identify high-frequency Volcano-Tectonic events (VT, >10 Hz) and Long-Period events (LP, 1-8 Hz). The former set of events is mainly associated with the local tectonics and power plant activities; while the latter has been generally recorded after strong earthquakes (Mw>7) occurred in Mexico.

Consequently, we adapted and applied two tomographic techniques to generate highly resolved seismic models; 1) the Enhanced Seismic Tomography (EST) method using the travel times of local seismic events. The method incorporates the Double Difference tomography and the post-processing Weighted Average Method to generate Vp and Vs models, and 2) the surface wave tomography method based on ambient noise analysis. In this case, we generated 3D anisotropic models of phase and group velocities of the Rayleigh and Love waves from Green functions retrieved by cross-correlation of the continuous records.

Thanks to the severe pre-processing of the whole seismic database that allowed to correct several errors on the data, and to the methods applied, we were able to obtain reliable and highly resolved models with both techniques.

Finally, the two sets of events (VT and LP) have been relocated using the 3D seismic velocity models of the region in order to better characterize the structure of the geothermal field and identify regions where the fluids could have a role on the triggering of the LP seismic activity observed.

This work is performed in the framework of the Mexican European consortium GeMex (Cooperation in Geothermal energy research Europe-Mexico, PT5.2 N: 267084 funded by CONACyT-SENER: S0019, 2015-04, and Horizon 2020, grant agreement No. 727550).
Signature of coalescence during scalar mixing in heterogeneous flow fields
Authors: Sen Sabyasachi , Singh Prajwal , Heyman Joris , Le Borgne Tanguy , Bandopadhyay Aditya
Published: March 2020

Stretching of fluid elements by a heterogeneous flow field, such as the flow through a porous media or geophysical flows such as atmospheric or oceanic vortices, is known to enhance mixing rates of scalar fields[1]. While the mechanisms leading to the elongation of material lines are well understood, predicting mixing rates still remains a challenge particularly when there is a reconnection (or aggregation) between several parts of the mixing interface, leading, at large mixing time, to a so-called coalescence regime[1][2]. In this presentation, we numerically study this coalescence dynamics through scalar transport in two different flow fields, the Rankine vortex and Stokes flow through a periodic bead pack[3]. The former is typical of large-scale turbulent flows [4] whereas the second is generic of small-scale laminar flows in porous media [5]. Both flows show a net elongation of the mixing interfaces, although at very different rates. To solve the transport problem in these flows, we use a Lagrangian method (the diffusive strip method[6]). This method allows us to reconstruct, at high resolution, the scalar concentration fields and to compute the evolution of the distribution of concentrations levels, scalar dissipation rate and scalar power spectrum in time. The signature of coalescence is clearly observed in both flows and we assess the influence of coalescence on the difference in mixing behaviour for the two flows. We finally discuss how coalescence may affect the reaction kinetics of mixing-limited reactive flows. The analysis proposed sheds light on fundamental aspects of transport and mixing in earth surface and subsurface flows.

[1] Emmanuel Villermaux. Mixing versus stirring. Annual Review of Fluid Mechanics, 51:245–273, 2019.
[2] Tanguy Le Borgne, Marco Dentz, and Emmanuel Villermaux. The lamellar description of mixing in porous media. Journal of Fluid Mechanics, 770:458–498, 2015.
[3] Régis Turuban, David R Lester, Tanguy Le Borgne, and Yves Méheust. Space-group symmetries generate chaotic fluid advection in crystalline granular media. Physical review letters, 120(2):024501, 2018.
[4] RT Pierrehumbert. Large-scale horizontal mixing in planetary atmospheres. Physics of Fluids A: Fluid Dynamics, 3(5):1250–1260, 1991.
[5] Brian Berkowitz, Andrea Cortis, Marco Dentz, and Harvey Scher. Modeling non-fickian transport in geological formations as a continuous time random walk. Reviews of Geophysics, 44(2), 2006.
[6] Patrice Meunier and Emmanuel Villermaux. The diffusive strip method for scalar mixing in two dimensions. Journal of fluid mechanics, 662:134–172, 2010.
Increase in the frequency of heavy rainfall events over the UK in the light of climate change.
Authors: Cotterill Daniel , Stott Peter , Kendon Elizabeth
Published: March 2020

We investigate the attribution of the flooding in Northern England that saw at least 500 homes flooded and over 1000 properties evacuated in flooded areas in 2019. This occurred during the wettest Autumn on record in some areas and also contained some very high daily rainfall totals. In the light of climate change, it is expected that intense rainfall events are to become more intense as a result of increased global average temperatures and the Clausius-Clapeyron relationship, but here we investigate quantitatively how much climate change has increased the risk of such an event to date.

We use results from the 2.2km convective permitting high resolution local UK Climate Projections (UKCP) and observations to show that more intense rainfall events may already be occurring in Autumn in the UK. This work shows using this high resolution UKCP data that a heavy rainfall event exceeding 50mm in one day in Autumn was 33-40% more likely to occur in 2019 than 1985. Further work that looks at the HadGEM3-A simulations shows that these heavy rainfall days are more likely to occur in a climate impacted by human activity than one with just natural climate forcings.
Bridging the gap from caldera unrest to resurgence
Authors: Acocella Valerio
Published: March 2020

Calderas often inflate up to a few metres for weeks to years, which is evidence of short-term unrest. Some calderas also show larger uplift (up to a thousand metres), achieved over the long-term (hundreds to thousands of years), manifest by a resurgent dome or block. How the short-term inflation relates to long-term resurgence is still poorly understood, even though established views consider the two processes distinct. This study exploits the longer deformation time series now available for several calderas, as well as the better understanding of magmatic processes and their evolution, to try to bridge the gap between these two scales of uplift. Available data challenge established views, suggesting that resurgence, rather than being produced by constant or continuous uplift, is the net cumulated result of tens to thousands distinct episodes of inflation, even interrupted by deflation episodes, as observed on short-term unrest. These inflation episodes are ascribed to distinct pulses of shallow magma emplacement, with most of the magma remaining intruded, especially in felsic calderas. This supports an incremental growth of magmatic systems, consistently with that observed below resurgent calderas and what is inferred for plutons. Comparing the uplift (as expression of the intrusive record) and eruptive histories or resurgent calderas opens new exciting research paths to understand the causal relationships between intruded and erupted magma at a given caldera, thus enhancing its long-term eruptive forecast.
Which DEM to use for glacier inventory applications? The example of Svalbard
Authors: Rastner Philipp , Paul Frank
Published: March 2020

Creating glacier inventories from satellite images and a digital elevation model (DEM) has become quasi standard. Besides the specific challenges for glacier mapping, also the selection of the ‘best’ DEM can be difficult. When using it to derive surface drainage divides and topographic information for each glacier, one has to consider the date of acquisition, artefacts, spatial completeness (data voids) and resolution. In general, using different DEMs gives different drainage divides and thus other glacier sizes. Moreover, due to widespread glacier retreat and rapid surface lowering, topographic information from older DEMs is increasingly biased towards too high values.

In this study we analyse seven freely available DEMs for the Arctic region of Svalbard: ALOS AW3D30, two National Elevation Datasets (NEDs), Arctic DEM, TanDEM-X (90 and 30 m products) and the ASTER GDEM2. All individual DEM tiles were mosaicked and re-projected bilinearly to UTM 33 N. Comparisons of topographic data are performed for three test regions: a) stable terrain (off glaciers), b) glaciers in rough topography, and c) flat glaciers and ice caps.

Overlay of drainage divides indicate large area differences on flat ice caps and small ones in rough topography, where mountain ridges are distinct. On the other hand, different spatial resolution results in large differences in rough topography but plays only a minor role for flat topography. Only 2 m elevation differences on stable terrain in flat valley bottoms were detected between the ALOS DEM (79.9m) and the two NEDs (77.9 m). No differences were found between the TanDEM-X 90 / 30 m and the Arctic DEM (all 109. 9 m). The ellipsoid-geoid difference is thus ~30 m in this region.

Mean elevations of glaciers with flat topography or ice caps differ only slightly, but in steeper topography they reach 6 to 8 m. These differences are also due to the different resolution of the DEMs. In all test regions, only small gaps are detected in the Arctic DEM and artefacts are especially present in the ALOS DEM. For this region the ‘best’ DEM is the TanDEM-X DEM.
Chaotic Caldera collapse: a new interpretation for the origin of Chaotic terrains on Mars
Authors: Luzzi Erica , Rossi Angelo Pio , Massironi Matteo , Pozzobon Riccardo , Maestrelli Daniele , Corti Giacomo
Published: March 2020

Chaotic terrains are broad regions on Mars characterized by the occurrence of angular-polygonal blocks separated by deep fractures and grabens, associated with collapse chains and with the overall mineralogy consisting mainly in basalts (Luzzi et al., submitted, 2020). Several mechanisms of formation for Chaotic terrains were proposed in the literature. While it is a shared opinion that the peculiar structures delineating the polygonal blocks of the Chaotic terrains are due to a collapse, the actual process at the origin of such collapse is still debated. Collapses due to the overpressure within a confined aquifer were proposed (Rodriguez et al., 2005; Andrews-Hanna & Phillips, 2007) as well as related to magma-ice/water interactions (Chapman & Tanaka, 2002; Leask et al., 2006; Meresse et al., 2008), or melting of a buried frozen lake (Zegers et al., 2010). We propose a new formation scenario for Chaotic Terrains: a Chaotic (or Piecemeal) Caldera collapse. In such a Caldera collapse the fragmentation of the floor is irregular and characterized by polygonal blocks. We reproduced this process in a series of analogue experiments similar to those performed by Troll et al. (2002): a rubber membrane was used to simulate the magma chamber with multiple cycles of inflation and deflation that generate the characteristic fractures in an overlying K-feldspar sand layer. We performed the experiments in different settings (different geometry of the magma chamber and different depth) and we found that the geometry of the basin is influenced mainly by the shape of the magma chamber. Moreover, after the second cycle of inflation and deflation, the deformation tends to be moderate, consisting only in the formation of minor fractures and not in deep structures, responsible for the polygonal blocks fragmentation, which are instead formed during the first cycles. From a morphological point of view, the reproduced geometry is strikingly similar to that of  Chaotic terrains on Mars. Further quantitative analyses on the DEMs are ongoing in order to assess the role played by each variable and refine a plausible collapse history for the specific case of study of Arsinoes Chaos.

REFERENCES

Andrews-Hanna, J. C., & Phillips, R. J. (2007). JGR: Planets, 112(E8).

Chapman, M. G., & Tanaka, K. L. (2002). Icarus, 155(2), 324–339.

Leask, H. J. et al. (2006). JGR: Planets, 111(E8).

Luzzi et al. (2020). EarthArXiv, DOI: 10.31223/osf.io/td297

Meresse, S. et al. (2008). Icarus, 194(2), 487–500.

Rodriguez, J. A. P. et al. (2005). Icarus, 175(1), 36–57.

Troll, V. R. et al. (2002). Geology, 30(2), 135–138.

Zegers, T. E. et al. (2010). Earth and Planetary Science Letters, 297(3–4), 496–504.
Up-scaling eclogitization : from experimental and natural aggregates behaviours to seismological signatures
Authors: Labrousse Loic , Sarah Incel , Sascha Zertani , Marie Baisset , Lisa Kaatz , Alexandre Schubnel , Timm John , Torgeir B. Andersen , Frederik Tilmann , Julien Gasc , Evangelos Moulas , Stefan Schmalholz , Johannes C. Vrijmoed , Joerg Renner
Published: March 2020

Eclogite formation in the subducting crust was the first metamorphic transformation to be acknowledged as important in the dynamics of convergent plate boundaries. It is indeed expected to affect the mass distribution via density change, but it also influence the fluid content of crustal and possibly lithospheric wedges; both density and fluids being first order in values measured by passive geophysical imaging such as tomography of receiver functions. Recent high accuracy focal mechanism solutions showing singular signatures in deep orogens actually imply that eclogitization could also have a signature in the seismological source signals, and hence have an impact at much shorter time-scales. This presentation aims at bridging what we know from the field and the lab at smaller time and space scales, to what we observe at larger scales in collision zones. Field-based studies show the ways a pristine rock can evolve from metastable to fully eclogitized from the thin section to the kilometre scale. More than the contrast between eclogitized and non-eclogitized domains, the eclogitization front itself is expected to be detected in the geophysics, especially when driven by strain. Indeed strain-assisted eclogitization develops a characteristic shear zone network pattern with a significant anisotropy. This network itself evolves with the eclogitization progress. The observed progressive widening and increasing connectivity of eclogite-facies shear zones with increasing fluid availability could actually be controlled by the transient properties of the newly formed assemblages, inducing fluid pressure gradients for instance. In this context it appears that the competition between reaction kinetics and strain-rate is a key factor. This is also the case at shorter time scales. Experimental studies show that strain of metastable assemblages in the eclogite facies is more likely to lead to mechanical instabilities for intermediate reaction kinetics, implying again that not the eclogite but the eclogitization rate is the smoking gun. Eclogitization of plagioclase-bearing rocks is the finite result of a large set of reactions involving different chemical subsystem (Na or Ca end-members, with or without fluid available), not reacting at the same pace. Further work is therefore needed on the kinetics of the different reactions and their interactions to distinguish the one(s) that controls the eclogitization front signature, and hence improve the seismological imaging acuity.
How Earthquake Early Warning Systems can affect scientist’s liability? International perspective for domestic questions.
Authors: Valbonesi Cecilia
Published: March 2020

How Earthquake Early Warning Systems can affect scientist’s liability? International perspective for domestic questions.

Early Warning Systems (EWS) represent a technical-scientific challenge aimed at improving the chance of surviving of the population exposed to the effects of dangerous natural events. This improvement must necessarily face great difficulties in the application fields, because EWS may turn into serious responsibilities for people involved as scientists and engineers.

In this complex scenario is necessary to consider the differences among EWS (e.g. meteo, tsunami, earthquake) and their capability of predicting and avoiding the consequences of damaging events.

The development of EWS in Italy is not homogenous.

Some of these systems, such as Earthquake EWS (EEWS), are in a testing phase and we really need to learn a lot from the comparison with other Countries that have been adopting these solutions for years.

This recognition is very important, because the tragic and deadly events of the L'Aquila earthquake, the landslide in Sarno, and the recent eruption of Stromboli volcano have taught us that the relationship between science and law in Italy is really difficult.

So, before entering in the operative phase of the EEWS is necessary to start from a recognition of the international and national legislative and jurisprudential frameworks that supports the assessment of criminal and civil liability in the event of a “wrong” technical-scientific response, unable to decrease the consequences for people and infrastructures.

The future application of EEWS in our Country must be supported by a study and research of solutions that allow scientists and engineers to operate with more awareness and less fear of the consequences of this not renounceable progress.

In this framework, the different roles of those involved in the development and dissemination of EEWS are also relevant: the responsibilities of scientists developing the tools are not the same as those of technical operators who are called upon to disseminate the alert.

In all these cases, however, the offer of an EEW service represents a promise to the population to face the harmful consequences of certain natural and disastrous events.

This promise certainly creates a legitimate expectation that, where betrayed, can give rise to criminal and civil liability for adverse events (manslaughter, negligence, unintentional disaster etc.).

Population, however, should not only expect to receive a correct alarm but must be put in the condition to understand the uncertainties involved in rapid estimates, to be prepared to face the risk, and to react in the right ways.
Testing in sandbox experiments the potentialities of active-Distributed Temperature Sensing to quantify distributed groundwater fluxes in porous media
Authors: Bour Olivier , Simon Nataline , Lavenant Nicolas , Porel Gilles , Nauleau Benoit , Pouladi Behzad , Longuevergne Laurent
Published: March 2020

Active-Distributed Temperature Sensing is a new method that has been recently developed for quantifying groundwater fluxes in the sub-surface along fibre-optic cables with a great spatial resolution. It consists in measuring and modelling the increase of temperature due to a heat source, dissipated through heat conduction and heat advection, depending on groundwater fluxes. Here, we propose to estimate the applicability and limitations of the method using sandbox experiments where flow rate and temperature are well controlled. For doing so, active-DTS experiments have been achieved under different flow rates and experimental conditions. In addition, we compare three different and complementary methods to estimate in practice the spatial resolution of DTS measurements. 

Active-DTS experiments have been conducted by deploying a fiber optic cable in a large PVC tank (1.6m long; 1.2 m width and 0.3 m height) and filled with 0.4-1.3 mm diameter sand. The height of water in water reservoirs on either side of the sandbox can be adjusted to control the head gradient and the flow rate through the sand. Heating was done by injecting during at least 8 hours for each experiment, a well-controlled electrical current along the steel armouring of the fiber optic cable. The three methods for estimating spatial resolution were applied and compared using FO-DTS measurements obtained on the same fiber-optic cable but with two different DTS units having different spatial resolution. Results show that a large range of groundwater fluxes may be estimated with a very good accuracy. Finally, we compare the advantages and complementarities of the different methods proposed for estimating the spatial resolution of measurements. In particular, the spatial resolution estimated using a temperature step change is both dependent on the effective spatial resolution of the DTS unit but also on heat conduction induced because of the high thermal conductivity of the cable. By showing the applicability of the method for a large range of flow rates and with an excellent spatial resolution, these experiments demonstrate the potentialities of the method for quantifying fluid fluxes in porous media for a large range of applications.
Mantle Plume – Spreading Ridge Interaction: A Comparative Study of the Red Sea and Reykjanes Ridges
Authors: Molitor Zachary , Jagoutz Oliver , Royden Leigh , Brown Stephanie , Port Guido , Dogru Ali , Keller Joao
Published: March 2020

As a young, mid ocean ridge, the Red Sea is a unique natural laboratory for studying the processes that drive continental rifting and breakup. The role of hot spots, frequently attributed to mantle plumes, in triggering or driving breakup and their impact on crustal structure and topography is not well understood. We have found that the Red Sea ridge bears a resemblance to the Reykjanes ridge in terms of bathymetry, morphology, geophysical properties, basalt chemistry, and modelled melting temperature and pressure of primary basalts. The results of modelling basalt melting temperature call into question the role of mantle temperature on generating excess melt beneath the Red Sea and Reykjanes ridges. Within 300 kilometers of a hotspot center, determined by seismic tomography, mantle excess temperatures are as high as 300 degrees relative to an ambient mantle temperature of about 1300 C. Outside of this radius excess temperatures are not significant (less than 50 C), and unlikely to cause significant melting anomalies. It is likely that the southern Red Sea and northern Reykjanes ridge are directly affected by hot, buoyant upwelling from the Afar and Iceland mantle plumes, and the central Red Sea and southern Reykjanes ridge may be affected by dynamic pressure related to actively upwelling mantle around the mantle plumes.
New 3D Pg and Sg Velocity Models for High-Resolution Seismotectonic Interpretations in the Central Alps
Authors: Diehl Tobias , Kissling Edi , Lee Timothy , Schmid Stefan , Herwegh Marco
Published: March 2020

The present-day deformation in the Central Alps is dominated by vertical uplift, at rates up to 1.5 mm/yr as indicated by high-precision levelling and GPS data. Understanding the driving mechanisms of this neotectonic uplift and its link to seismicity in the Central Alps requires accurate locations of current deformation processes within the upper crust. Especially the question if and how deformation in the crystalline basement is coupled with deformation in the overlaying nappe systems is key to understand the neotectonic processes. Seismicity provides important information on deformation in the uppermost crust, however, an accuracy of focal depths in the order of few kilometers and less is required to distinguish sources in the basement from sources in the sedimentary cover.

In this study, we demonstrate how insufficient crustal velocity models and inconsistent seismic phase selection can lead to biased hypocenter solutions, which hamper such high-resolution seismotectonic interpretations. We propose a relocation procedure combining a new high-resolution Pg and Sg 3D crustal model of the Central Alps with a dynamic seismic phase selection to overcome this bias and to improve accuracy of hypocenter solutions. The new tomographic model is based on more than 60,000 Pg and 30,000 quality-checked Sg phases of earthquakes, which occurred in the greater Central Alpine region between 1996 and 2019. In combination with a nonlinear, probabilistic earthquake location algorithm, the model was used to relocate more than 18’000 earthquakes, which occurred in this region over the past 36 years. The derived catalog includes a consistent error and quality assessment, calibrated against ground-truth events like quarry blasts.

The relocated seismicity in the Central Alps is interpreted together with additional information from the tomographic model, focal mechanisms, geophysical, geological and geodetic data. We focus our interpretation on the eastern Aar massif as well as on the Rawil depression, located in-between the outcropping Aar and Aiguilles-Rouge massifs. Both regions were recently affected by remarkable seismic events. The ML4.6 Urnerboden earthquake of 2017 occurred near the eastern termination of the Aar massif, while a sequence of about 350 events occurred in the Rawil earthquake lineament near the Sanetschpass in November 2019. Both sequences provide unique insights into active faults in the Central Alps and we image systems of sub-vertically oriented strike-slip faults of variable strike, which root in the crystalline basement in both regions. Our results document the existence of active strike-slip fault systems in the External Crystalline Massifs of the Central Alps in regions of maximum change in uplift rates. We therefore discuss possible models relating the observed strike-slip kinematics to buoyancy-driven vertical tectonic processes.
Lagrangian dynamics in the Gulf of Trieste from high resolution HF-Radar
Authors: Reyes-Suarez Nydia Catalina , Hernandez-Carrasco Ismael , Licer Matjaz , Cardin Vanessa , Gacic Miroslav , Orfila Alejandro
Published: March 2020

The Gulf of Trieste (GoT) is shared by Italy, Slovenia and Croatia, with most of its coasts belonging to Italy and Slovenia, along with the two main harbours; the Harbour of Trieste (Italy) and Koper (Slovenia). Both are subject to heavy marine traffic and exposed to different threats including oil spills, maritime accidents and SAR operations. The GOT High frequency radar network provides near-real time data of sea surface currents and waves since 2016. In this work we provide a statistical description of surface variability in terms of Lagrangian descriptors in order to elucidate the transport and retention in the GoT as well as to provide the seasonal evolution of the residence time. Among the most widely used Lagrangian techniques, we focus the study on Lagrangian Coherent Structures and Path-integrated topological variables like Lagrangian divergence and Lagrangian vorticity.
Amazon Carbon Balance affected by human activities and Climate change
Authors: Gatti Luciana Vanni , Basso Luana , Domingues Lucas , Cassol Henrique , Marani Luciano , Miller John , Gloor Manuel , Aragao Luiz , Arai Egidio , Tejada Graciela , Anderson Liana , Von Randow Celso , Peters Wouter , Ipia Sanchez Alber , Correia Caio , Crispim Stephane , Neves Raiane
Published: March 2020

Amazon is the major tropical land region, with critical processes, such as the carbon cycle, not yet fully understood. Only very few long-term greenhouse gas measurements regionally represented is available in the tropics. The Amazon accounts for 50% of Earth’s tropical rainforests hosting the largest carbon pool in vegetation and soils (~200 PgC). The net carbon exchange between tropical land and the atmosphere is critically important because the stability of carbon in forests and soils can be disrupted in short time-scales. The main processes releasing C to the atmosphere are deforestation, degradation, fires and changes in growing conditions due to increased temperatures and droughts. Such changes may thus cause feedbacks on global climate.

In the last 40 years, Amazon mean temperature increased by 1.1ºC. The length and intensity of the dry season is also increasing, causing a strong stress each year higher to the forest.

We observed a reduction of 17% in precipitation during dry season and the transition dry to wet season during this same period. This reduction in precipitation and the increase in temperature during the dry season exacerbate vegetation water stress, with consequences for carbon balance.

To understand the consequences of human-driven and climate changes on the C budget of Amazonia, we put in place the first program with regional representativeness, from 2010 onwards, aiming to quantify greenhouse gases based on extensive collection of vertical profiles of CO2 and CO. Regular vertical profiles from the ground up to 4.5 km height were performed at four sites along the main air-stream over the Amazon. Along this period from 2010 to 2018, we performed 669 vertical profiles, over four strategic regions that represent fluxes over the entire Amazon region.

The observed variability of carbon fluxes during these 9 years is correlated with climate variability (Temperature, precipitation, GRACE, EVI) and human-driven changes (Biomass Burning). The correlations were performed inside each influenced area for each studied site and show how high temperature and water stress during dry season are affecting the Amazon Carbon Balance. At Southeast of Amazon these extreme conditions are dominating the annual balance. Fire emission is the main source of carbon to the atmosphere, which is not compensate by the C removal from old-growth Amazon forest. The west Amazon almost compensate the east carbon source. During wet/normal years Amazon Carbon Balance is around neutral, but during dry years the uptake capacity is very compromised.
Geometry of surface deformations caused by induced shocks in the area of underground copper exploitation
Authors: Owczarz Karolina , Kopeć Anna , Głąbicki Dariusz
Published: March 2020

The level of intensity of induced seismic phenomena occurring in areas of mining activity is very diverse. Induced shocks may be directly related to the exploitation carried out or to mining and tectonic factors. In the case of impact on the surface, two types of mining tremors are distinguished: energetically weak shocks, not causing surface deformation, and shocks exceeding a certain energy level, which cause terrain deformations. Surface displacements are the most common form of the effects of underground mining operations, including induced seismicity. Geological research uses Sentinel-1 imagery to determine the geometry of surface displacements that were caused by induced shocks by satellite radar interferometry. In this research four induced shocks with magnitude M>4.0 was used, which occurred in the Legnica-Glogow Copper District in the Rudna mine. This area is one of the most seismically active places in Poland due to the underground exploitation of copper ore. For calculations, the differential satellite radar interferometry (DInSAR) method was used. The DInSAR technique allowed the determination of surface displacement towards the Line of Sight (LOS) between two images acquired at different times (before and after induced shock) with millimeter accuracy. In the presented research calculations were carried out separately for observations acquired in descending and ascending orbits. The Sentinel-1 satellites are a constellation of two radar satellites that observe the surface of lands and oceans at a time interval of 6 days. Therefore, 6 days, 12 days, 18 days and 24 days were assumed as the time intervals between the images. Vertical displacements were calculated based on the generated LOS displacement maps. In addition, charts of subsidence in the N-S and W-E directions were prepared, 3D models of subsidence were made, and deformation geometry was analyzed for individual shocks. As a result of the research, the spatial extent of deformation in the horizontal surface was determined: N-S and W-E, which in both directions was over 2 km. However, surface displacements caused by induced shocks reached values up to 10 cm.
Implementing irrigation techniques in CESM2
Authors: Yao Yi , Swenson Sean , Lawrence Dave , Thiery Wim
Published: March 2020

Several recent studies have highlighted the importance of irrigation-induced changes in climate. Earth system models are a common tool to address this question, and to this end, irrigation is increasingly being represented in their land surface modules. Despite this evolution, currently, none of them considers different irrigation techniques. Here we develop and test a new parameterization that represents irrigation activities in the Community Land Model version 5 (CLM5) and considers three main irrigation techniques (surface, sprinkler and drip irrigation). Using global maps of the areas equipped by different irrigation systems, we will employ version 2 of the Community Earth System Model (CESM2) and its improved irrigation representation to detect the impacts of irrigation on climate. Two control experiments are designed, one with the new irrigation scheme and another with the original one. We will conduct an evaluation by comparing the simulated results against observed surface fluxes and meteorological variables. Subsequently, the differences between the experiments will be analyzed to quantify the impacts of irrigation on climate. We anticipate that our results will uncover whether considering different irrigation schemes is of value for exploring irrigate-induced impacts on climate.