Review: Thermal water resources in carbonate rock aquifers   总被引：3，自引：1，他引：2  

Nico Goldscheider  Judit Mádl-Szőnyi  Anita Erőss  Eva Schill 《Hydrogeology Journal》2010,18(6):1303-1318

The current knowledge on thermal water resources in carbonate rock aquifers is presented in this review, which also discusses geochemical processes that create reservoir porosity and different types of utilisations of these resources such as thermal baths, geothermal energy and carbon dioxide (CO₂) sequestration. Carbonate aquifers probably constitute the most important thermal water resources outside of volcanic areas. Several processes contribute to the creation of porosity, summarised under the term hypogenic (or hypogene) speleogenesis, including retrograde calcite solubility, mixing corrosion induced by cross-formational flow, and dissolution by geogenic acids from deep sources. Thermal and mineral waters from karst aquifers supply spas all over the world such as the famous bath in Budapest, Hungary. Geothermal installations use these resources for electricity production, district heating or other purposes, with low CO₂ emissions and land consumption, e.g. Germany’s largest geothermal power plant at Unterhaching near Munich. Regional fault and fracture zones are often the most productive zones, but are sometimes difficult to locate, resulting in a relatively high exploration uncertainty. Geothermal installations in deep carbonate rocks could also be used for CO₂ sequestration (carbonate dissolution would partly neutralise this gas and increase reservoir porosity). The use of geothermal installations to this end should be further investigated.  相似文献   

Mineralogical and geochemical spatial analyses of a waste-rock dump at the Libiola Fe–Cu sulphide mine (Eastern Liguria,Italy)     

Pietro Marescotti  Eva Azzali  Diego Servida  Cristina Carbone  Giovanni Grieco  Luisa De Capitani  Gabriella Lucchetti 《Environmental Earth Sciences》2010,61(1):187-199

In this work, we investigated a 3 ha sulphide-bearing waste-rock dump (Libiola Mine, Italy) using mineralogical, geochemical, and geostatistical analyses. The dumped materials were highly heterogeneous in grain size and lithology and varied both laterally and vertically. Other than the host rock of the ore, basalts and serpentinites, the dumped materials contained high amounts of low-grade chalcopyrite- and pyrite-rich mineralisations. Due to these characteristics and to the absence of minerals able to neutralise acidity, this waste-rock dump can be classified as an acid mine drainage (AMD) producer. The study confirms that AMD is still active and, in the best scenario, can persist for up to 6.17 × 10³ years. The consequences of this process are of serious environmental concern as it involves strong acidification of the circulating waters, the release of potentially toxic metals into the soil, streams and rivers and the precipitation of huge quantities of secondary Fe-oxides and Fe-oxyhydroxides.  相似文献   

Are assemblages of the fireworm Hermodice carunculata enhanced in sediments beneath offshore fish cages?     

Rodrigo Rier  Oscar P&#;rez  Myriam Rodr&#;guez  Eva Ramos  &#;scar Monterroso 《海洋学报(英文版)》2014,33(4):108-111

Abundances of the fireworm Hermodice carunculata were counted through a monitoring assessment study of fish cages in Barranco Hondo（NE Tenerife）. Seven campaigns were conducted from November 2007 to June 2010 and temporal variations were found, as well as differences among sampling stations. The polychaete H. carunculata obtained its highest abundance in sediments beneath fish cages throughout the study period. Thus, the assemblages of this omnivorous species were favoured by the presence of fish cages.  相似文献   

Trends in Canadian Short‐Duration Extreme Rainfall: Including an Intensity–Duration–Frequency Perspective     

Mark W. Shephard  Eva Mekis  Robert J. Morris  Yang Feng  Xuebin Zhang  Karen Kilcup 《大气与海洋》2014,52(5):398-417

Short-duration (5 minutes to 24 hours) rainfall extremes are important for a number of purposes, including engineering infrastructure design, because they represent the different meteorological scales of extreme rainfall events. Both single location and regional analyses of the changes in short-duration extreme rainfall amounts across Canada, as observed by tipping bucket rain gauges from 1965 to 2005, are presented. The single station analysis shows a general lack of a detectable trend signal, at the 5% significance level, because of the large variability and the relatively short period of record of the extreme short-duration rainfall amounts. The single station 30-minute to 24-hour durations show that, on average, 4% of the total number of stations have statistically significant increasing amounts of rainfall, whereas 1.6% of the cases have significantly decreasing amounts. However, regional spatial patterns are apparent in the single station trend results. Thus, for the same durations regional trends are presented by grouping the single station trend statistics across Canada. This regional trend analysis shows that at least two-thirds of the regions across Canada have increasing trends in extreme rainfall amounts, with up to 33% being significant (depending on location and duration). Both the southwest and the east (Newfoundland) coastal regions generally show significant increasing regional trends for 1- and 2-hour extreme rainfall durations. For the shortest durations of 5–15 minutes, the general overall regional trends in the extreme amounts are more variable, with increasing and decreasing trends occurring with similar frequency; however, there is no evidence of statistically significant decreasing regional trends in extreme rainfall amounts. The decreasing regional trends for the 5- to 15-minute duration amounts tend to be located in the St. Lawrence region of southern Quebec and in the Atlantic provinces. Additional analysis using criteria specified for traditional water management practice (e.g., Intensity-Duration-Frequency (IDF)) shows that fewer than 5.6% and 3.4% of the stations have significant increasing and decreasing trends, respectively, in extreme annual maximum single location observation amounts. This indicates that at most locations across Canada the traditional single station IDF assumption that historical extreme rainfall observations are stationary (in terms of the mean) over the period of record for an individual station is not violated. However, the trend information is still useful complementary information that can be considered for water management purposes, especially in terms of regional analysis.  相似文献   

Development of satellite green vegetation fraction time series for use in mesoscale modeling: application to the European heat wave 2006     

Joakim Refslund  Ebba Dellwik  Andrea N. Hahmann  Michael J. Barlage  Eva Boegh 《Theoretical and Applied Climatology》2014,117(3-4):377-392

A method is presented for development of satellite green vegetation fraction (GVF) time series for use in the Weather Research and Forecasting (WRF) model. The GVF data is in the WRF model used to describe the temporal evolution of many land surface parameters, in addition to the evolution of vegetation. Several high-resolution GVF products, derived from high-quality satellite retrievals from Moderate Resolution Imaging Spectroradiometer images, were produced and their performance was evaluated in long-term WRF simulations. The atmospheric conditions during the 2006 heat wave year over Europe were simulated since significant interannual variability in vegetation seasonality was found. Such interannual variability is expected to increase in the coming decades due to climatic changes. The simulation using a quadratic normalized difference vegetation index to GVF relationship resulted in consistent improvements of modeled temperatures. The model mean temperature cold bias was reduced by 10 % for the whole domain and by 20–45 % in areas affected by the heat wave. The study shows that WRF simulations during heat waves and droughts, when vegetation conditions deviate from the climatology, require concurrent land surface properties in order to produce accurate results.  相似文献   

Monitoring of heat transmission from buildings into geological environment and evaluation of soil deformation consequences in foundation engineering     

Işık Yilmaz  Marian Marschalko  David Lamich  Marián Drusa  Jiří Machačík  Silvie Heviánková  Miroslav Kyncl  Eva Lacková  Iva Bestová  David Krčmář  Egon Stutz  Martin Bednárik 《Environmental Earth Sciences》2014,72(8):2947-2955

In engineering geology a number of factors affecting foundation conditions are taken into consideration during engineering-geological investigations. This article deals with the factor of heat sourced from a structure (brick kiln) as a restrictive factor in foundation engineering in clay soils and introduces a documentation of soil deformation observations as an impact of the heat transmission into the geological environment. It was carried out in Southern Moravia in the Czech Republic, where the dominant foundation soils are Neogeneous clays where differential settlements of a tunnel kiln structure occurred as a result of ignoring the boundary conditions of temperature changes in the soil environment. The brick kilns caused heterogeneous spatial changes in the subsoil temperatures. This consequently resulted in differential settlements due to temperature changes originating from the kilns. The differential settlements reached as much as 150 mm. The major objective of the article is to highlight the importance of the heat transmission from buildings into the geological environment as a factor which should be considered in engineering geology and its application in planning. A new procedure for reducing or elimination of ground movements sourced from underlying clayey soils depending on the heat changes was also suggested in this context.  相似文献   

Paleolithic vs. Epipaleolithic fisheries in northern Iberia     

Pablo Turrero  Alba Ardura  Eva García-Vázquez 《Quaternary Research》2014

A comparison of Paleolithic and Epipaleolithic fisheries in NW Iberia shows an overall high trophic level of catch. Freshwater fisheries (and thus their impacts) are ca. 8000 yr older than marine fisheries and have suffered virtually no changes in the region except for the increase in numbers, being focused on two families (Salmonidae, and Anguillidae to a very minor extent). Marine fisheries in the Paleolithic likely had a low impact but rapidly increased in importance, raising the average trophic level of the catch, the number of affected taxa and the proportion of marine to freshwater fisheries with time.  相似文献   

High‐pressure phase transitions of α‐quartz under nonhydrostatic dynamic conditions: A reconnaissance study at PETRA III          下载免费PDF全文

Eva‐Regine Carl  Ulrich Mansfeld  Hanns‐Peter Liermann  Andreas Danilewsky  Falko Langenhorst  Lars Ehm  Ghislain Trullenque  Thomas Kenkmann 《Meteoritics & planetary science》2017,52(7):1465-1474

Hypervelocity collisions of solid bodies occur frequently in the solar system and affect rocks by shock waves and dynamic loading. A range of shock metamorphic effects and high‐pressure polymorphs in rock‐forming minerals are known from meteorites and terrestrial impact craters. Here, we investigate the formation of high‐pressure polymorphs of α‐quartz under dynamic and nonhydrostatic conditions and compare these disequilibrium states with those predicted by phase diagrams derived from static experiments under equilibrium conditions. We create highly dynamic conditions utilizing a mDAC and study the phase transformations in α‐quartz in situ by synchrotron powder X‐ray diffraction. Phase transitions of α‐quartz are studied at pressures up to 66.1 and different loading rates. At compression rates between 0.14 and 1.96 GPa s^?1, experiments reveal that α‐quartz is amorphized and partially converted to stishovite between 20.7 GPa and 28.0 GPa. Therefore, coesite is not formed as would be expected from equilibrium conditions. With the increasing compression rate, a slight increase in the transition pressure occurs. The experiments show that dynamic compression causes an instantaneous formation of structures consisting only of SiO₆ octahedra rather than the rearrangement of the SiO₄ tetrahedra to form a coesite. Although shock compression rates are orders of magnitude faster, a similar mechanism could operate in impact events.  相似文献   

Time distributions in satellite constellation design     

David Arnas  Daniel Casanova  Eva Tresaco 《Celestial Mechanics and Dynamical Astronomy》2017,128(2-3):197-219

The aim of the time distribution methodology presented in this paper is to generate constellations whose satellites share a set of relative trajectories in a given time, and maintain that property over time without orbit corrections. The model takes into account a series of orbital perturbations such as the gravitational potential of the Earth, the atmospheric drag, the Sun and the Moon as disturbing third bodies and the solar radiation pressure. These perturbations are included in the design process of the constellation. Moreover, the whole methodology allows to design constellations with multiple relative trajectories that can be distributed in a minimum number of inertial orbits.  相似文献   

Lightning‐flash locations related to the precipitation pattern of the storm     

E.J. Stansbury  Eva Cherna  James Percy 《大气与海洋》2013,51(4):277-290

Abstract

Triangulation from paired sferics (100 ± 50 kHz) received at stations 57 km apart gave 42 map locations of lightning flashes belonging to a thunderstorm well‐defined on weather radar. This storm was one of many in a long line along the leading edge of a band of light stratiform precipitation (snow above 3 km). The band was 9 km high and 60 km wide, and the storms were embedded in it. The convective region of the storm studied had a north‐south extent of 20 km, the east‐west extent averaging two‐thirds as much. Cumulus heights progressed from 3 km on the west to 7 ± 1 km on the east. Two‐thirds of the lightning flashes were in the convective region. The remaining third were in 160 km² of the light stratiform precipitation immediately west of it.  相似文献