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31.
Comprehensive hazard mitigation involves (1) understanding natural systems, (2) assessment of interactions within and between social systems and the built environment, and (3) understanding geo-spatial processes. To achieve this, local emergency managers must recognize variability in vulnerable populations exposed to hazards and develop place-based emergency plans accordingly. In this study, we assess whether cities in Los Angeles County are subject to disproportionally greater earthquake losses modeled from a M7.8 earthquake on the San Andreas fault. Furthermore, we analyze whether the variation in demographic and socioeconomic characteristics across cities is associated with the earthquake losses. We were able to explain 23.2?% of variance in economic losses by looking at the percentage of minority residents, income, and renter residents in a city [F(3,84)?=?8.47; p?<?.001]. Cities with primarily minority residents had greater economic losses when compared to cities with primarily White residents (b?=?1.01; p?<?.001). When looking at the association between demographic predictors and potential casualty rate, the percentage of Hispanic residents was positively associated with the potential casualty rate. We argue that knowledge of the relationship between earthquake hazard and the demographic characteristics of people in the area at risk is essential to mitigate the local impact from earthquakes. In other words, we apply social vulnerability assessment as part of a comprehensive risk management framework to accelerate recovery after an event. Local policy makers and the private sector can use this approach to gain a better understanding of a city??s social vulnerability and adapt their preparedness efforts accordingly.  相似文献   
32.
F. Suter  M. Sartori  R. Neuwerth  G. Gorin   《Tectonophysics》2008,460(1-4):134-157
The northern Andes are a complex area where tectonics is dominated by the interaction between three major plates and accessory blocks, in particular, the Chocó-Panamá and Northern Andes Blocks. The studied Cauca Valley Basin is located at the front of the Chocó-Panamá Indenter, where the major Romeral Fault System, active since the Cretaceous, changes its kinematics from right-lateral in the south to left-lateral in the north. Structural studies were performed at various scales: DEM observations in the Central Cordillera between 4 and 5.7°N, aerial photograph analyses, and field work in the folded Oligo-Miocene rocks of the Serranía de Santa Barbara and in the flat-lying, Pleistocene Quindío-Risaralda volcaniclastic sediments interfingering with the lacustrine to fluviatile sediments of the Zarzal Formation.The data acquired allowed the detection of structures with a similar orientation at every scale and in all lithologies. These families of structures are arranged similarly to Riedel shears in a right-lateral shear zone and are superimposed on the Cretaceous Romeral suture.They appear in the Central Cordillera north of 4.5°N, and define a broad zone where 060-oriented right-lateral distributed shear strain affects the continental crust. The Romeral Fault System stays active and strain partitioning occurs among both systems. The southern limit of the distributed shear strain affecting the Central Cordillera corresponds to the E–W trending Garrapatas–Ibagué shear zone, constituted by several right-stepping, en-échelon, right-lateral, active faults and some lineaments. North of this shear zone, the Romeral Fault System strike changes from NNE to N.Paleostress calculations gave a WNW–ESE trending, maximum horizontal stress, and 69% of compressive tensors. The orientation of σ1 is consistent with the orientation of the right-lateral distributed shear strain and the compressive state characterizing the Romeral Fault System in the area: it bisects the synthetic and antithetic Riedels and is (sub)-perpendicular to the active Romeral Fault System.It is proposed that the continued movement of the Chocó–Panamá Indenter may be responsible for the 060-oriented right-lateral distributed shear strain, and may have closed the northern part of the Cauca Valley, thereby forming the Cauca Valley Basin.Conjugate extensional faults observed at surface in the flat-lying sediments of the Zarzal Formation and Quindío-Risaralda volcaniclastic Fan are associatedwith soft-sediment deformations. These faults are attributed to lateral spreading of the superficial layers during earthquakes and testify to the continuous tectonic activity from Pleistocene to Present.Finally, results presented here bring newinformation about the understanding of the seismic hazard in this area: whereas the Romeral Fault Systemwas so far thought to be themost likely source of earthquakes, themore recent cross-cutting fault systems described herein are another potential hazard to be considered.  相似文献   
33.
Land surface temperature is one of the most important parameters related to global warming. It depends mainly on soil type, discontinuous vegetation cover, or lack of precipitation. The main purpose of this paper is to investigate the relationship between high LST, synoptic conditions and air masses trajectories, vegetation cover, and soil type in one of the driest region in Romania. In order to calculate the land surface temperature and normalized difference vegetation index, five satellite images of LANDSAT missions 5 and 7, covering a period of 26 years (1986–2011), were selected, all of them collected in the month of June. The areas with low vegetation density were derived from normalized difference vegetation index, while soil types have been extracted from Corine Land Cover database. HYSPLIT application was employed to identify the air masses origin based on their backward trajectories for each of the five study cases. Pearson, logarithmic, and quadratic correlations were used to detect the relationships between land surface temperature and observed ground temperatures, as well as between land surface temperature and normalized difference vegetation index. The most important findings are: strong correlation between land surface temperature derived from satellite images and maximum ground temperature recorded in a weather station located in the area, as well as between areas with land surface temperature equal to or higher than 40.0 °C and those with lack of vegetation; the sandy soils are the most prone to high land surface temperature and lack of vegetation, followed by the chernozems and brown soils; extremely severe drought events may occur in the region.  相似文献   
34.
The distribution and structure of the Mesozoic and Cenozoic cover within the central part of the North Iberian Margin (Bay of Biscay) is analysed based on a dense set of 2D seismic reflection lines and logs. The integration of well data allows the recognition of seven seismostratigraphic units and the construction of a surface that illustrates the 3D morphology of this area at the time of the Jurassic rifting. The study zone comprises what is known as Le Danois Bank, a basement high, and the Asturian Basin, one of the sedimentary basins originated during the Iberian rifting at the end of the Paleozoic. Its development continued with the oceanisation of the Bay of Biscay as a failed arm of the Atlantic rift; later, during the Cenozoic, a drastic change in tectonic regime induced the partial closure of Biscay and building up the Cantabrian?Pyrenean chain along the northern border of Iberia. This compressional period left its imprint in the Asturian Basin sediments in the form of a mild inversion and general uplift. The geometry of the basin bottom appears as an asymmetric bowl thinning out towards the edges, with a main E‐W depocenter, separated by E‐W striking faults from a secondary one. Those bounding faults show twisted trends in the north, interpreted as a consequence of the compressional period, when a transfer zone in a N‐S direction formed between the two E‐W striking deformation fronts in Biscay. This study shows that the transfer zone extends further to the west, reaching the longitude of Le Danois Bank. The maximum thickness of the filling within the Asturian Basin is estimated in more than 10 km, deeper than assessed in previous studies. The recognition of frequent halokynetic structures at this longitude is another observation worth to remark. Based on this study, it is suggested that the basin formed on top of a distal basement block of stretched crust limiting with the hyperextended rifted domain of Biscay. This location largely conditioned its deformation during the late compression.  相似文献   
35.
As a contribution to an environmental study on Tuscany's marine shelf, textural, mineralogical, and chemical characteristics of recent sediments in the northern Tyrrhenian Sea between Elba Island and Livorno have been analyzed. The data provide clear information on sediment sources and movement patterns. The main sediment source appears to be the Cecina River; very subordinate is the contribution of the Fine River. As to sediment movement patterns, the surveyed basin appears to be divided into two subbasins: (1) a greater, southern subbasin, bounded by Tuscany mainland, Elba Island and Elba Ridge, and Capraia Isle, and Vada Shoals; and (2) a smaller, northern subbasin, enclosed between Vada Shoals and Meloria Shoals (off Livorno port).In the former the coarse-grade Cecina River sediments are transported southward along most of the mainland coast by littoral drift and coastal current; a northward flowing countercurrent seems to be active only in the southernmost part. Silts and clays are distributed in concentric belts around basin's central part, being transported mainly by slow circular water movements. In the marginal western zone, very little terrigenous influx is coupled with a high biologic productivity, and biogenic debris sedimentation prevails there.In the northern subbasin the sediment contribution from Fine River is more appreciable. Here the environmental energies are very low and the coarse sediments are restricted to a few small pocket beaches where they are deposited by local creeks. Most of the subbasin area is occupied by sapropelitic muds, again distributed by slow small-scale gyres.  相似文献   
36.
37.
Talc and/or pyrophyllite have been detected as suspended particulates in the waters of the Ionian Sea (eastern Mediterranean). Differing from similar findings reported in some recent works by many authors, the presence of these silicates is completely attributable to unavoidable contamination during collection and analytical processing of the water samples.  相似文献   
38.
This paper examines contemporary struggles over hydrocarbon governance in Ecuador and Bolivia. Our comparative analysis illustrates the ways that petro-capitalism, nationalist ideologies, popular movements and place conjoin in the governance of oil and natural gas. In the case of Ecuador, state employees drew on their labor relations and political training to oppose the government’s efforts to privatize the state oil company. In Bolivia, urban popular movements opposed the privatization of the hydrocarbons industry and its domination by foreign firms. In both cases, hydrocarbons struggles involved the production of imaginative geographies of the nation and it hydrocarbon resources, which in turn drew on historical memories of nationhood. Whereas neoliberal political and economic restructuring sought to re-organize national hydrocarbons companies, redraw concessions, and draft new resource extraction laws, hydrocarbon movements aimed to counter these processes by re-centering hydrocarbon governance within a populist vision of the nation-state. In contrast to analyses of resource conflict in the environmental security and resource curse literatures, the cases of Ecuador and Bolivia demonstrate that such struggles cannot be reduced to models of opportunity structure, war profiteering, or resource scarcity (or abundance). Rather, these cases show that political economy and cultural politics are inseparable in the context of resource conflicts, which involve struggles over the meanings of development, citizenship and the nation itself.  相似文献   
39.
40.
The theory of satellite loss resulting from a giant impact on Uranus (Parisi and Brunini 1997, Planet. Space Sci.45, 181-187) is revisited, in the light of the discovery of its five outer moons (Gladman et al. 1998, Nature392, 897-899; Gladman et al. 2000, Icarus147, 320-324; erratum 148, 320). Physical conditions and dynamical constraints in the great collision scenario and restrictions in the possible mechanisms for the origin of the outer uranian satellites are obtained from the knowledge of their actual orbital properties. We conclude that the existence of these moons implies that their origin must be connected to a breakup process. Other scenarios for their origin cast serious doubts on the occurrence of a giant collision at the end of Uranus' formation process to account for its large spin axis obliquity.  相似文献   
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