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151.
Surface rupture and source fault of the 20 February 1956 Eskişehir earthquake have been a matter of debate that potentially
contributes towards the understanding of the active deformation and seismic risk in the highly populated NW Anatolia. Field
observations on the two fault segments (namely Kavacık and Uludere faults) in the north of the Eskişehir graben revealed evidences
of co-seismic surface rupture and mass movements during the Eskişehir earthquake. Surface rupture was observed as a 2.5m wide,
a 100m long and ca. 20 cm deep asymmetric depression in the Gümüşlü valley, 2 km east of the Uludere village. A trench dug
on this depression confirms a prominent high-angle south dipping fault (dominantly left lateral strike slip) and two faint
north-dipping antithetics as clear noticeable shear zones in organic-rich thick soil. Mass failures are particularly observed
in spring depressions filled with loose torrent and carbonaceous material in front of the fault scarp. Some rock slides of
several tens of meters in size that obviously require significantly high ground shaking were also developed on steep fault
scarps. The orientation of the principal stress tensor as deduced from the surface rupture of the Eskişehir earthquake displays
clear inconsistency with the geometry of prominent faults in the area. We concluded that this disagreement may be explained
by a curved surface rupture. The western and eastern tips of this rupture are EW trending and the probable NW-running part
in the middle would correspond to the bounding zone between two right-stepping faults. 相似文献
152.
153.
The Soultz Enhanced Geothermal System (EGS) reservoir's response to chemical stimulation is assessed by numerical simulation of coupled thermo-hydraulic-chemical processes. To assess chemical interactions between host rocks and a mixture of HCl and HF as well as its potential effects on the Soultz EGS reservoir, new modelling efforts using the FRACHEM code have been initiated. This article presents the model calibration and results. Simulations consider realistic conditions with available data sets from the EGS system at Soultz. Results indicate that the predicted amount of fracture sealing minerals dissolved by injection of a mixture of acids Regular Mud Acid (RMA) was consistent with the estimated amount from the test performed on GPK4 well at Soultz EGS site. Consequently reservoir porosity and permeability can be enhanced especially near the injection well by acidizing treatment. 相似文献
154.
155.
Isabel Pôças João Gonçalves Bruno Marcos Joaquim Alonso Pedro Castro João P. Honrado 《International journal of geographical information science》2014,28(11):2356-2371
This article proposes and illustrates a practical methodological framework to evaluate the fitness for use of spatial data sets for environmental and ecological applications, focusing on user requirements for specified application contexts. The methodology is based on the use of metadata to analyze similarity between the data characteristics and the user’s needs or expectations for several quality indicators. Additionally, the concept of ‘critical factors’ is introduced in this framework, allowing users to define which quality indicators have greater importance given their own requirements or expectations and the specified application contexts. The proposed methodology further allows integrating and interconnecting the spatial data quality (SDQ) evaluation methodology with metadata geoportals in WebGIS platforms, facilitating its operation by users from non-spatial disciplines and with often limited expertise on this subject. Examples of the evaluation of fitness for use for specific application contexts within the project BIO_SOS (‘Biodiversity Multi-SOurce Monitoring System: From Space To Species’ FP7 project) are presented. By providing a prompt and straightforward evaluation tool, the proposed methodology can encourage the implementation of SDQ evaluation routines in ecological assessment and monitoring programs, promoting a more adequate use of geospatial data and ultimately contributing to well-supported policy and management decisions. 相似文献
156.
157.
Ivana Tošić Ivana Hrnjak Milivoj B. Gavrilov Miroslava Unkašević Slobodan B. Marković Tin Lukić 《Theoretical and Applied Climatology》2014,117(1-2):331-341
Annual and seasonal variability of precipitation observed at 92 stations in Vojvodina (Serbia) were analyzed during the period 1946–2006. The rainfall series were examined by means of the empirical orthogonal functions (EOF). The first set of singular vectors explains from 68.8 % (in summer) to 81.8 % (in winter) of the total variance. The temporal variability of the time series associated with the main EOF configurations (the principal components, PCs) was examined using the Mann–Kendall test and the spectral analysis. The time series of PC1 revealed decreasing trend in the winter and spring precipitation and increasing trend in the autumn, summer, and annual precipitation. The relationships between the first PC and circulation patterns, such as the North Atlantic Oscillation (NAO), the East Atlantic (EA) pattern, and East Atlantic/West Russia pattern, were also investigated. The PC1, displaying temporal behavior of the first mode, demonstrated evident correspondence with the NAO index in analysis of the annual, winter, and autumn precipitation. Power spectra of the PC1 show statistically significant oscillations of about 3.3 years for the spring precipitation and about 8 and 15 years for the winter precipitation. Comparisons with spectral analysis of authors for some regions in Europe, most of them in the Mediterranean domain, show that similar periodicities are detected. 相似文献
158.
David Barriopedro David Gallego M. Carmen Alvarez-Castro Ricardo García-Herrera Dennis Wheeler Cristina Peña-Ortiz Susana M. Barbosa 《Climate Dynamics》2014,43(3-4):939-955
A monthly index based on the persistence of the westerly winds over the English Chanel is constructed for 1685–2008 using daily data from ships’ logbooks and comprehensive marine meteorological datasets. The so-called Westerly Index (WI) provides the longest instrumental record of atmospheric circulation currently available. Anomalous WI values are associated with spatially coherent climatic signals in temperature and precipitation over large areas of Europe, which are stronger for precipitation than for temperature and in winter and summer than in transitional seasons. Overall, the WI series accord with the known European climatic history, and reveal that the frequency of the westerlies in the eastern Atlantic during the twentieth century and the Late Maunder Minimum was not exceptional in the context of the last three centuries. It is shown that the WI provides additional and complementary information to the North Atlantic Oscillation (NAO) indices. The analysis of WI series during the industrial era indicates an overall good agreement with the winter and high-summer NAO, with the exception of several multidecadal periods of weakened correlation. These decoupled periods between the frequency and the intensity of the zonal flow are interpreted on the basis of several sources of non-stationarity affecting the centres of the variability of the North Atlantic and their teleconnections. Comparisons with NAO reconstructions and long instrumental indices extending back to the seventeenth century suggest that similar situations have occurred in the past, which call for caution when reconstructing the past atmospheric circulation from climatic proxies. The robustness and extension of its climatic signal, the length of the series and its instrumental nature make the WI an excellent benchmark for proxy calibration in Europe and Greenland. 相似文献
159.
M. Gonçalves A. Barrera-Escoda D. Guerreiro J. M. Baldasano J. Cunillera 《Climatic change》2014,122(1-2):243-256
The complex topography and high climatic variability of the North Western Mediterranean Basin (NWMB) require a detailed assessment of climate change projections at high resolution. ECHAM5/MPIOM global climate projections for mid-21st century and three different emission scenarios are downscaled at 10 km resolution over the NWMB, using the WRF-ARW regional model. High resolution improves the spatial distribution of temperature and precipitation climatologies, with Pearson's correlation against observation being higher for WRF-ARW (0.98 for temperature and 0.81 for precipitation) when compared to the ERA40 reanalysis (0.69 and 0.53, respectively). However, downscaled results slightly underestimate mean temperature (≈1.3 K) and overestimate the precipitation field (≈400 mm/year). Temperature is expected to raise in the NWMB in all considered scenarios (up to 1.4 K for the annual mean), and particularly during summertime and at high altitude areas. Annual mean precipitation is likely to decrease (around ?5 % to ?13 % for the most extreme scenarios). The climate signal for seasonal precipitation is not so clear, as it is highly influenced by the driving GCM simulation. All scenarios suggest statistically significant decreases of precipitation for mountain ranges in winter and autumn. High resolution simulations of regional climate are potentially useful to decision makers. Nevertheless, uncertainties related to seasonal precipitation projections still persist and have to be addressed. 相似文献
160.
Basement lithostratigraphy of the Adula nappe: implications for Palaeozoic evolution and Alpine kinematics 总被引:1,自引:0,他引:1
Mattia Cavargna-Sani Jean-Luc Epard François Bussy Alex Ulianov 《International Journal of Earth Sciences》2014,103(1):61-82
The Adula nappe belongs to the Lower Penninic domain of the Central Swiss Alps. It consists mostly of pre-Triassic basement lithologies occurring as strongly folded and sheared gneisses of various types with mafic boudins. We propose a new lithostratigraphy for the northern Adula nappe basement that is supported by detailed field investigations, U–Pb zircon geochronology, and whole-rock geochemistry. The following units have been identified: Cambrian clastic metasediments with abundant carbonate lenses and minor bimodal magmatism (Salahorn Formation); Ordovician metapelites associated with amphibolite boudins with abundant eclogite relicts representing oceanic metabasalts (Trescolmen Formation); Ordovician peraluminous metagranites of calc-alkaline affinity ascribed to subduction-related magmatism (Garenstock Augengneiss); Ordovician metamorphic volcanic–sedimentary deposits (Heinisch Stafel Formation); Early Permian post-collisional granites recording only Alpine orogenic events (Zervreila orthogneiss). All basement lithologies except the Permian granites record a Variscan + Alpine polyorogenic metamorphic history. They document a complex Paleozoic geotectonic evolution consistent with the broader picture given by the pre-Mesozoic basement framework in the Alps. The internal consistency of the Adula basement lithologies and the stratigraphic coherence of the overlying Triassic sediments suggest that most tectonic contacts within the Adula nappe are pre-Alpine in age. Consequently, mélange models for the Tertiary emplacement of the Adula nappe are not consistent and must be rejected. The present-day structural complexity of the Adula nappe is the result of the intense Alpine ductile deformation of a pre-structured entity. 相似文献