Ressi is a small (2.4 ha) forested catchment located in the Italian pre-Alps. The site became an experimental catchment to investigate the water fluxes in the soil–plant–atmosphere continuum and the impact of vegetation on runoff generation in 2012. The elevation of the catchment ranges from 598 to 721 m a.s.l. and the climate is humid temperate. The bedrock consists of rhyolites and dacites; the soil is a Cambisol. The catchment is covered by a dense forest, dominated by beech, chestnut, maple, and hazel trees. The field set up includes measurements of the rainfall in an open area, streamflow at the outlet, soil moisture at various depths and locations, and depth to water table in six piezometers at a 5- or 10-min interval. Samples of precipitation, stream water, shallow groundwater and soil water are collected monthly for tracer analysis (stable isotopes (2H and 18O), electrical conductivity and major ions), and during selected rainfall–runoff events to determine the contribution of the various sources to runoff. Since 2017, soil and plant water samples have been collected to determine the sources of tree transpiration. Data collected in the period 2012–2016 are publicly available. Data collection is ongoing, and the data set is expected to be updated on an annual basis to include the most recent measurements. 相似文献
The Nain and Ashin ophiolites consist of Mesozoic melange units that were emplaced in the Late Cretaceous onto the continental basement of the Central-East Iran microcontinent(CEIM).They largely consist of serpentinized peridotites slices;nonetheless,minor tectonic slices of sheeted dykes and pillow lavas-locally stratigraphically associated with radiolarian cherts-can be found in these ophiolitic melanges.Based on their whole rock geochemistry and mineral chemistry,these rocks can be divided into two geochemical groups.The sheeted dykes and most of the pillow lavas show island arc tholeiitic(IAT)affinity,whereas a few pillow lavas from the Nain ophiolites show calc-alkaline(CA)affinity.Petrogenetic modeling based on trace elements composition indicates that both IAT and CA rocks derived from partial melting of depleted mantle sources that underwent enrichment in subduction-derived components prior to melting.Petrogenetic modeling shows that these components were represented by pure aqueous fluids,or sediment melts,or a combination of both,suggesting that the studied rocks were formed in an arc-forearc tectonic setting.Our new biostratigraphic data indicate this arc-forearc setting was active in the Early Cretaceous.Previous tectonic interpretations suggested that the Nain ophiolites formed,in a Late Cretaceous backarc basin located in the south of the CEIM(the so-called Nain-Baft basin).However,recent studies showed that the CEIM underwent a counter-clockwise rotation in the Cenozoic,which displaced the Nain and Ashin ophiolites in their present day position from an original northeastward location.This evidence combined with our new data and a comparison of the chemical features of volcanic rocks from different ophiolites around the CEIM allow us to suggest that the Nain-Ashin volcanic rocks and dykes were formed in a volcanic arc that developed on the northern margin of the CEIM during the Early Cretaceous in association with the subduction,below the CEIM,of a Neo-Tethys oceanic branch that was existing between the CEIM and the southern margin of Eurasia.As a major conclusion of this paper,a new geodynamic model for the Cretaceous evolution of the CEIM and surrounding Neo-Tethyan oceanic basins is proposed. 相似文献
In the current world, it is easy to listen that everybody and everything is connected. Over this connected world, the concept of location-based services has grown in order to provide digital services in everyplace and at every time. Nevertheless, this is not 100% true because the connection is not guaranteed for many people and in many places. These are the Degraded Communications Environments (DCE), environments where the availability of high-speed communications is not guaranteed in at least the 75% of the time. This paper works over the experience of a previous work in developing light protocols that do not need broadband for communication. This work provides an extension of these protocols for the inclusion of mobile devices as elements of the communication process and a set of libraries to allow the development of applications in DCE. The work done has involved the development of two frameworks: an Android framework that makes the incorporation of Android devices easier and a server-based framework that provides the server side for the development of the referred applications. A use case that uses these two frameworks has been developed. Finally, all technology developed is available throw a public Git repository. 相似文献
This study investigates the impact of model complexity and multi-scale prior hydrogeological data on the interpretation of pumping test data in a dual-porosity aquifer (the Chalk aquifer in England, UK). In order to characterize the hydrogeological properties, different approaches ranging from a traditional analytical solution (Theis approach) to more sophisticated numerical models with automatically calibrated input parameters are applied. Comparisons of results from the different approaches show that neither traditional analytical solutions nor a numerical model assuming a homogenous and isotropic aquifer can adequately explain the observed drawdowns. A better reproduction of the observed drawdowns in all seven monitoring locations is instead achieved when medium and local-scale prior information about the vertical hydraulic conductivity (K) distribution is used to constrain the model calibration process. In particular, the integration of medium-scale vertical K variations based on flowmeter measurements lead to an improvement in the goodness-of-fit of the simulated drawdowns of about 30%. Further improvements (up to 70%) were observed when a simple upscaling approach was used to integrate small-scale K data to constrain the automatic calibration process of the numerical model. Although the analysis focuses on a specific case study, these results provide insights about the representativeness of the estimates of hydrogeological properties based on different interpretations of pumping test data, and promote the integration of multi-scale data for the characterization of heterogeneous aquifers in complex hydrogeological settings. 相似文献
International Journal of Earth Sciences - Our research is aimed at estimating the vertical deformation affecting late Quaternary units accumulated into the foreland basin of the Northern Apennines... 相似文献
In 2010, the south flank of Mount Meager failed catastrophically, generating the largest (53 ± 3.8 × 106 m3) landslide in Canadian history. We document the slow deformation of the edifice prior to failure using archival historic aerial photographs spanning the period 1948–2006. All photos were processed using Structure from Motion (SfM) photogrammetry. We used the SfM products to produce pre-and post-failure geomorphic maps that document changes in the volcanic edifice and Capricorn Glacier at its base. The photographic dataset shows that the Capricorn Glacier re-advanced from a retracted position in the 1980s then rapidly retreated in the lead-up to the 2010 failure. The dataset also documents 60 years of progressive development of faults, toe bulging, and precursory failures in 1998 and 2009. The 2010 collapse was conditioned by glacial retreat and triggered by hot summer weather that caused ice and snow to melt. Meltwater increased pore water pressures in colluvium and fractured rocks at the base of the slope, causing those materials to mobilize, which in turn triggered several secondary failures structurally controlled by lithology and faults. The landslide retrogressed from the base of the slope to near the peak of Mount Meager involving basement rock and the overlying volcanic sequence. Elsewhere on the flanks of Mount Meager, large fractures have developed in recently deglaciated areas, conditioning these slopes for future collapse. Potential failures in these areas have larger volumes than the 2010 landslide. Anticipated atmospheric warming over the next several decades will cause further loss of snow and glacier ice, likely producing additional slope instability. Satellite- and ground-based monitoring of these slopes can provide advanced warning of future landslides to help reduce risk in populated regions downstream. 相似文献
The carbonate factories, their controlling factors and their palaeoecological and sedimentological signals recorded in sedimentary successions are key elements for understanding the evolution of carbonate platform systems. Luis Pomar has dedicated most of his academic life to the study of carbonate rocks and carbonate factories. The idea for this special issue to celebrate Pomar’s career arose during a session at the 34th International Association of Sedimentologists meeting held in Rome, entitled ‘Understanding carbonate factories through palaeoecological and geochemical signals’. The proposal encountered great response among participants, and additional contributions followed an email invitation to other specialists. This issue contains a variety of papers on carbonate sedimentology and carbonate factories. Here, an introduction that contextualizes the papers and key concepts discussed in this thematic issue is provided. It reviews Luis Pomar’s major achievements in carbonate sedimentology and discusses the evolution of the concept of the carbonate factory and the series of palaeoecological and sedimentological signals used to characterize the wide spectrum of carbonate depositional systems found in the natural world. 相似文献
Optical fibre–based sensors have now established their place in the field of geohazard monitoring due to their sensitivity to strain and temperature changes. Progressive development in the technology leads to the availability of novel, accurate and durable sensors at a relatively limited cost. This creates room for original monitoring applications that have been, so far, impeded by the shortcomings of conventional monitoring tools. In this work, we explore the applicability of an interferometric optical fibre sensor as a vibration sensing tool at laboratory scale. We tested the ability of the sensor to identify precursors of instability in a downscaled model of a rainfall-induced landslide composed of granular material. We carried out four experimental tests which involved different sensor deployments and soil mixtures. The recorded signals were processed by means of a time–frequency analysis and we identified two frequency-domain parameters—the spectral centroid and band power—that could provide information on the development of instability. Their ratio yielded a unique parameter through which a precursory stage could be outlined by defining a threshold value based on the data collected at the beginning of the experiment. In our lab tests, precursors of instability were detected 2–3 min before a crack was observed at the surface. This may upscale to a lead time of about 20–30 min or more in the field, classifying our monitoring approach in between an alarm and a warning system. The work presented here can be considered a first promising step towards an innovative monitoring system and shows the potential of optical fibre sensing as a shallow landslide monitoring technique, encouraging further testing, especially in real-case studies.
Native bismuth in the form of metallic melt has been considered instrumental to the formation of some metallic ore deposits via a mechanism dubbed the “Liquid Bismuth Collector Model.” Here, we provide petrographical documentation of trail‐forming, μm‐sized blebs of native bismuth in cassiterite–quartz veins from the Santa Bárbara greisen Sn deposit in the Rondônia tin province of northern Brazil. These inclusions suggest the trapping of a Bi melt that took place during vein formation, in a mechanism similar to the entrapment of fluid inclusions. 相似文献