Foreword special issue LORCA’s earthquake     

Enrique Alarcón  Mª Belén Benito Oterino 《Bulletin of Earthquake Engineering》2014,12(5):1827-1829

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Performance of buildings with masonry infill walls during the 2011 Lorca earthquake   总被引：1，自引：1，他引：0  

Lutz Hermanns  Alberto Fraile  Enrique Alarcón  Ramón Álvarez 《Bulletin of Earthquake Engineering》2014,12(5):1977-1997

On Wednesday 11th May 2011 at 6:47 pm (local time) a magnitude 5.1 Mw earthquake occurred 6 km northeast of Lorca with a depth of around 5 km. As a consequence of the shallow depth and the small epicentral distance, important damage was produced in several masonry constructions and even led to the collapse of one of them. Pieces of the facades of several buildings fell down onto the sidewalk, being one of the reasons for the killing of a total of 9 people. The objective of this paper is to describe and analyze the failure patterns observed in reinforced concrete frame buildings with masonry infill walls ranging from 3 to 8 floors in height. Structural as well as non-structural masonry walls suffered important damage that led to redistributions of forces causing in some cases the failure of columns. The importance of the interaction between the structural frames and the infill panels is analyzed by means of non-linear Finite Element Models. The resulting load levels are compared with the member capacities and the changes of the mechanical properties during the seismic event are described and discussed. In the light of the results obtained the observed failure patterns are explained. Some comments are stated concerning the adequacy of the numerical models that are usually used during the design phase for the seismic analysis.  相似文献   

Numerical simulation of the 30–45 ka debris avalanche flow of Montagne Pelée volcano,Martinique: from volcano flank collapse to submarine emplacement     

Brunet  Morgane  Moretti  Laurent  Le Friant  Anne  Mangeney  Anne  Fernández Nieto  Enrique Domingo  Bouchut  Francois 《Natural Hazards》2017,85(2):1189-1208

Natural Hazards - In November 2015, China government announced that the national carbon emissions trading market is expected to start in 2017. Carbon emission trading system is a raising concern...  相似文献   

Using very long-range terrestrial laser scanner to analyze the temporal consistency of the snowpack distribution in a high mountain environment     

Juan I. López-Moreno  Jesús Revuelto  E. Alonso-González  Alba Sanmiguel-Vallelado  Steven R. Fassnacht  Jeffrey Deems  Enrique Morán-Tejeda 《山地科学学报》2017,14(5):823-842

This study demonstrated the usefulness of very long-range terrestrial laser scanning (TLS) for analysis of the spatial distribution of a snowpack, to distances up to 3000 m, one of the longest measurement range reported to date. Snow depth data were collected using a terrestrial laser scanner during 11 periods of snow accumulation and melting, over three snow seasons on a Pyrenean hillslope characterized by a large elevational gradient, steep slopes, and avalanche occurrence. The maximum and mean absolute snow depth error found was 0.5-0.6 and 0.2-0.3 m respectively, which may result problematic for areas with a shallow snowpack, but it is sufficiently accurate to determine snow distribution patterns in areas characterized by a thick snowpack. The results indicated that in most cases there was temporal consistency in the spatial distribution of the snowpack, even in different years. The spatial patterns were particularly similar amongst the surveys conducted during the period dominated by snow accumulation (generally until end of April), or amongst those conducted during the period dominated by melting processes (generally after mid of April or early May). Simple linear correlation analyses for the 11 survey dates, and the application of Random Forests analysis to two days representative of snow accumulation and melting periods indicated the importance of topography to the snow distribution. The results also highlight that elevation and the Topographic Position index (TPI) were the main variables explaining the snow distribution, especially during periods dominated by melting. The intra- and inter-annual spatial consistency of the snowpack distribution suggests that the geomorphological processes linked to presence/absence of snow cover act in a similar way in the long term, and that these spatial patterns can be easily identified through several years of adequate monitoring.  相似文献   

The contrasted evolution of high and low flows and precipitation indices in the Duero basin (Spain)     

Enrique Morán-Tejeda  Juan Ignacio López-Moreno  Sergio M. Vicente-Serrano  Jorge Lorenzo-Lacruz  Antonio Ceballos-Barbancho 《水文科学杂志》2013,58(4):591-611

Abstract

Trends in high and low flows are valuable indicators of hydrological change because they highlight changes in various parts of the frequency distribution of streamflow series. This enables improved assessment of water availability in regions with high seasonal and inter-annual variability. There has been a substantial reduction in water resources in the Duero basin (Iberian Peninsula, Spain) and other areas of the Mediterranean region during the last 50 years, and this is likely to continue because of climate change. In this study, we investigated the evolution and trends in high and low flows in the Spanish part of the Duero basin, and in equivalent or closely-related precipitation indices for the period 1961–2005. The results showed a general trend of decrease in the frequency and magnitude of high flows throughout most of the basin. Moreover, the number of days with low flows significantly increased over this period. No clear relationship was evident between the evolution of high/low flows and changes in the distribution frequencies of the precipitation series. In contrast to what was expected, the number of days with heavy precipitation and the mean annual precipitation did not show significant trends across the basin, and the number of days without rainfall decreased slightly. The divergence between precipitation and runoff evolution was more accentuated in spring and summer. In the absence of trends in precipitation, it is possible that reforestation processes in the region, and increasing temperatures in recent decades, could be related to the decreasing frequency of high flows and the increasing frequency of low flows.

Editor Z.W. Kundzewicz; Associate editor S. Grimaldi

Citation Morán-Tejeda, E., López-Moreno, J.I., Vicente-Serrano, S.M., Lorenzo-Lacruz, J. and Ceballos-Barbancho, A., 2012. The contrasted evolution of high and low flows and precipitation indices in the Duero basin (Spain). Hydrological Sciences Journal, 57 (4), 591–611.  相似文献   

Effect of galvanic distortions on the series and parallel magnetotelluric impedances and comparison with other responses     

Enrique Gómez-Treviño  Francisco Javier Esparza Hernández  José Manuel Romo Jones 《Geofísica Internacional》2013,52(2):135-152

The series and parallel impedances of the magnetotelluric tensor are appraised in relation to their relative immunity to galvanic electric distortions. The distorted responses are modeled using the Groom-Bailey decomposition of the tensor in terms of twist, shear, statics and strike direction. These four parameters and the undistorted responses are normally considered as unknowns, and are obtained from field data through the solution of an inverse problem. In the present work we use the decomposition as a forward model to simulate distorted sounding curves. Starting with undistorted 2-d te and tm responses, the tensor is distorted by assuming arbitrary values of twist, shear, static and strike direction. By default, both series and parallel responses are immune to the strike direction because they are invariants under rotation. In addition, series responses are immune to twist and shear and parallel responses only to twist. The dependence of the latter on shear is in the form of a real factor that shifts downwards the amplitude curves. On the other hand, the effect of statics on both series and parallel responses is more complicated than that on the impedance tensor because it cannot be accounted for by a simple shift of the curves. On the whole, there is a positive balance on the part of the series and parallel impedances over the te and tm responses because some of the distortions are filtered out by the invariants. It is shown that invariance is not sufficient to be immune to any of the distortions. The example chosen is Eggers’ eigenvalues, which are immune only to the by-the-fault strike direction. Invariance is not necessary either, as evidenced by the phase tensor, whose elements depend on strike but are immune to all distortions. The derivations are illustrated using soundings from the synthetic coprod2s1 and field-recorded coprod2 and bc87 data sets.  相似文献   

Mapping the Land Cover of Mexico Using AVHRR Time‐Series Data Sets     

Miguel A. Ortega-Huerta  Enrique Martinez-Meyer  Stephen L. Egbert  Kevin P. Price  A. Townsend Peterson 《国际地球制图》2013,28(3):7-20

Abstract

An important methodological and analytical requirement for analyzing spatial relationships between regional habitats and species distributions in Mexico is the development of standard methods for mapping the country's land cover/land use formations. This necessarily involves the use of global data such as that produced by the Advanced Very High Resolution Radiometer (AVHRR). We created a nine‐band time‐series composite image from AVHRR Normalized Difference Vegetation Index (NDVI) bi‐weekly data. Each band represented the maximum NDVI for a particular month of either 1992 or 1993. We carried out a supervised classification approach, using the latest comprehensive land cover/vegetation map created by the Mexican National Institute of Geography (INEGI) as reference data. Training areas for 26 land cover/vegetation types were selected and digitized on the computer's screen by overlaying the INEGI vector coverage on the NDVI image. To obtain specific spectral responses for each vegetation type, as determined by its characteristic phenology and geographic location, the statistics of the spectral signatures were subjected to a cluster analysis. A total of 104 classes distributed among the 26 land cover types were used to perform the classification. Elevation data were used to direct classification output for pine‐oak and coastal vegetation types. The overall correspondence value of the classification proposed in this paper was 54%; however, for main vegetation formations correspondence values were higher (60‐80%). In order to obtain refinements in the proposed classification we recommend further analysis of the signature statistics and adding topographic data into the classification algorithm.  相似文献   

Population Structure of the SW Atlantic Estuarine Crab Neohelice granulata Throughout Its Range: a Genetic and Morphometric Study     

Romina B. Ituarte  Alejandro D’Anatro  Tomás A. Luppi  Pablo D. Ribeiro  Eduardo D. Spivak  Oscar O. Iribarne  Enrique P. Lessa 《Estuaries and Coasts》2012,35(5):1249-1260

Phylogeographic patterns of the SW Atlantic estuarine crab Neohelice granulata were examined using mitochondrial DNA cytochrome oxidase I sequences and analyzed together with morphometric data. Specimens were sampled during a 4-year period (2001?C2004) from 11 localities encompassing the full distributional range of this species along the SW Atlantic (22°57?? S to 42°25?? S). DNA sequences were obtained from 69 individuals belonging to seven localities, and morphometric variation in 12 continuous characters was analyzed for 646 crabs from ten localities. Strong genetic differentiation, consistent with a pattern of isolation-by-distance, was detected among all localities indicating that gene flow occurs mainly between neighboring populations. Analyses of molecular variance showed genetic subdivision between the southern (Argentina) and the northern (Brazil) sites, suggesting restricted gene flow at a regional scale. The genetic structure of this species could be divided into two distinct groups due to a limited gene flow between southern and northern regions as a consequence of larval dispersal patterns. Coastal currents in the vicinity of the Rio de la Plata likely act as a barrier to dispersal within the species range. Moreover, genetic data indicate that populations of N. granulata might have undergone a northward demographic expansion since the late Pleistocene. The morphometric analysis showed no geographical pattern of morphological differentiation, although there were differences among sampling sites.  相似文献   

On the use of IPCC-class models to assess the impact of climate on Living Marine Resources     

Charles A. Stock  Michael A. Alexander  Nicholas A. Bond  Keith M. Brander  William W.L. Cheung  Enrique N. Curchitser  Thomas L. Delworth  John P. Dunne  Stephen M. Griffies  Melissa A. Haltuch  Jonathan A. Hare  Anne B. Hollowed  Patrick Lehodey  Simon A. Levin  Jason S. Link  Kenneth A. Rose  Ryan R. Rykaczewski  Jorge L. Sarmiento  Ronald J. Stouffer  Franklin B. Schwing  Francisco E. Werner 《Progress in Oceanography》2011,88(1-4):1-27

The study of climate impacts on Living Marine Resources (LMRs) has increased rapidly in recent years with the availability of climate model simulations contributed to the assessment reports of the Intergovernmental Panel on Climate Change (IPCC). Collaboration between climate and LMR scientists and shared understanding of critical challenges for such applications are essential for developing robust projections of climate impacts on LMRs. This paper assesses present approaches for generating projections of climate impacts on LMRs using IPCC-class climate models, recommends practices that should be followed for these applications, and identifies priority developments that could improve current projections. Understanding of the climate system and its representation within climate models has progressed to a point where many climate model outputs can now be used effectively to make LMR projections. However, uncertainty in climate model projections (particularly biases and inter-model spread at regional to local scales), coarse climate model resolution, and the uncertainty and potential complexity of the mechanisms underlying the response of LMRs to climate limit the robustness and precision of LMR projections. A variety of techniques including the analysis of multi-model ensembles, bias corrections, and statistical and dynamical downscaling can ameliorate some limitations, though the assumptions underlying these approaches and the sensitivity of results to their application must be assessed for each application. Developments in LMR science that could improve current projections of climate impacts on LMRs include improved understanding of the multi-scale mechanisms that link climate and LMRs and better representations of these mechanisms within more holistic LMR models. These developments require a strong baseline of field and laboratory observations including long time series and measurements over the broad range of spatial and temporal scales over which LMRs and climate interact. Priority developments for IPCC-class climate models include improved model accuracy (particularly at regional and local scales), inter-annual to decadal-scale predictions, and the continued development of earth system models capable of simulating the evolution of both the physical climate system and biosphere. Efforts to address these issues should occur in parallel and be informed by the continued application of existing climate and LMR models.  相似文献   

Intra-oceanic settings of the western Mexico Late Jurassic-Early Cretaceous arc sequences. Implications for the Pacific-Tethys geodynamic relationships during the Cretaceous     

Marc Tardy  Henriette Lapierre  Jean-Louis Bourdier  Christian Couloni  R. Juventino Martinezr  H. Enrique Ortiz 《Geodinamica Acta》2013,26(3):174-185

Abstract

The Guerrero suspect terrane composed of Late Jurassic-Early Cretaceous sequences, extends from Baja California up to Acapulco and is considered to be coeval with the Late Mesozoic igneous and sedimentary arc sequences of the Greater Antilles, Venezuela and Western Cordillera of Colombia. New geological, petrological and geochemical data from central and southern Mexico, led us to propose a new model for the building of the Alisitos-Teloloapan arc. This arc, partly built on the Pacific oceanic lithosphere and partly on continental fragments, could be related to the subduction of an oceanic basin - the Arperos basin - under the Paleo-Pacific plate. This subduction was dipping southwest.

At the beginning of the magmatic activity of the oceanic segment of this arc, depleted tholeiitic basalts were emitted in a submarine environnement below the CCD. While subduction was going on, the arc magmas evolved from LREE depleted tholeiites to slightly LREE enriched tholeiites and then, to calc-alkaline basalts and andesites enriched in LREE and HFSE. Concurrently, the arc sedimentary environment changed from deep oceanic to neritic with the deposition of Aptian-Albian reefal limestones, at the end of the arc building. In the continent-based segment, the arc magmas are exclusively differentiated calc-alkaline suites depleted in HREE and Y, formed of predominantly siliceous lavas and pyroclastic rocks, emitted in a sub-aerial or shallow marine environment.

Thus, taking into account this above mentioned model, the Cretaceous volcanic series, accreted to the margins of cratonal America, in Colombia, Venezuela, Greater Antilles and Mexico, could be related to the same west-south-west dipping subduction of oceanic basins, fringing the North and South American continental cratons and connected directly with the inter-American Tethys. While the subduction was proceeding, this magmatic arc drifted towards the North and South American cratons and finally, collided with the continental margins at different periods during the Cretaceous.  相似文献