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1.
As a result of work carried out during the first two stages of the Global Seismic Hazard Assessment Program (GSHAP) for the Test Area Caucasus, a uniform earthquake catalogue was compiled and a Seismic Source Zones Model was designed. At the final stage of the program, the computation of seismic hazard was done by different methods.The results of a computation done using the Probabilistic Seismic Hazard Assessment methodology, as well as primary intermediate steps and preparatory work are given in the present paper. Peak horizontal ground acceleration is chosen as the parameter representing seismic hazard. Final computer calculations were done with the SEISRISK III program. The two final Seismic Hazard maps for different return periods are presented. The work was carried out at the National Survey for Seismic Protection of the Republic of Armenia. 相似文献
2.
The preparation of the preliminary seismic hazard maps of the territory of Slovenia has been based on an expansion of the basic approach laid out by Cornell in 1968. Three seismic source models were prepared. Two of them are based mainly on the earthquake catalogue using the Poissonian probability model. A map of seismic energy release and a map of earthquake epicenter density are used to delineate seismic sources in these models. The geometry of the third model which is based on a rough estimate of seismotectonic setting is taken from the probabilistic seismic hazard analysis of a nuclear power plant in Slovenia. Published ground motion attenuation models based on strong motion records of recent strong earthquakes in Italy are used. Test maps for variable and uniform b-values are presented. The computer program, Seisrisk III, developed by the U.S. Geological Survey is used. 相似文献
3.
In this paper, we present a probabilistic seismic hazard analysis (PSHA) for mainland Spain that takes into account recent
new results in seismicity, seismic zoning, and strong ground attenuation not considered in the latest PSHA of the Spanish
Building Code. Those new input data have been obtained as a three-step project carried out in order to improve the existing
hazard map for mainland Spain. We have produced a new earthquake catalogue for the area, in which the earthquakes are given
in moment magnitude through specific deduced relationships for our territory based on intensity data (Mezcua et al. in Seismol
Res Lett 75:75–81, 2004). In addition, we included a new seismogenetic zoning based on the recent partial zoning studies performed by different authors.
Finally, as we have developed a new strong ground motion model for the area García Blanco (2009), it was considered in the hazard calculation together with other attenuations gathered from different authors using data
compatible with our region. With this new data, a logic tree process is defined to quantify the epistemic uncertainty related
to those parts of the process. A sensitivity test has been included in order to analyze the different models of ground motion
and seismotectonic zonation used in this work. Finally, after applying a weighting scheme, a mean hazard map for PGA, based
on rock type condition for 10% exceedance probability in 50 years, is presented, including 15th and 85th percentile hazard
maps. The main differences with the present official building code hazard map are analyzed. 相似文献
4.
Sisir K. Mondal 《Journal of the Geological Society of India》2011,78(4):390-391
News and Notes
National Seminar on Orissa’s Mineral, Environment and Geosciences Assessment — 2011 (OMEGA-2011) and Golden Jubilee of Geological Survey of India, Orissa — M. Mohanty and K. C. Sahoo (Email: manoranjanmoha@gmail.com) 相似文献5.
Application of groundwater sustainability indicators to the carbonate aquifer of the Sierra de Becerrero (Southern Spain) 总被引：3，自引：1，他引：2
L. J. Lambán S. Martos M. Rodríguez-Rodríguez J. C. Rubio 《Environmental Earth Sciences》2011,64(7):1835-1848
The objective of this study was to test the applicability of groundwater sustainability indicators defined by UNESCO, together
with the International Academy of Environmental Sciences (IAES), the International Association of Hydrogeology (IAH) Group
on Groundwater Indicators and the Geological Survey of Spain (IGME), to the aquifer scale. We selected four main indicators
based on their relevance in the field of groundwater sustainability and because they proved to be the most reliable, based
on the data collection and methodology utilized. These indicators were applied to a small—26 km2 of permeable outcrops—carbonate aquifer situated in the province of Seville (southern Spain), which has semi-arid climate
conditions (500 mm/year). The integral application of all these indicators in this particular groundwater body leads us to
conclude that, at present, the aquifer is undergoing intensive use. Therefore, the exploitation of its water resources is
surpassing the threshold of sustainability when both the quantity and the quality of the groundwater are taken into consideration.
The continued increase in exploitation generates a descending trend in the evolution of the piezometric levels, a consequence
of adaptation to the new hydrodynamic situation, and also results in exhaustion of the springs that drain the aquifer in undisturbed
conditions. At the same time, there is a trend of increasing salinity in the groundwater and a risk of contamination by nitrate
which, according to the EU Water Framework Directive and the Groundwater Daughter Directive (EU Official Journal of the European
Communities L327, 2000; EU Official Journal of the European Communities L372/19, 2006), should be controlled and reduced. In the future, application of the methodology described here may prove useful for the
evaluation of similar systems, either in southern Spain or in other countries with semi-arid climates. 相似文献
6.
Jon C. Atkinson 《Environmental Earth Sciences》2011,64(1):37-46
This paper expands significantly on the major-ion geochemical characterization, evolution, and differentiation of groundwater
in the Presidio-Redford Bolson (PRB) Aquifer of Texas as presented in Chowdhury et al. (2008). For 19 groundwater samples from the PRB Aquifer, the author calculated major cation–anion balance errors, equilibrium carbon
dioxide partial pressure values and saturation indices for selected minerals. Comparison of major-ion analyses for groundwater
from basin margin wells with those for basin center wells is documented and illustrated with ion-concentration maps and Piper
and Stiff diagrams and reveals significant increases in concentrations of chloride, sulfate and sodium coupled with notable
decrease of calcium in bolson-center well samples. These geochemical changes suggest dissolution of aquifer minerals and cation
exchange as groundwater migrates downgradient to the bolson center. The US Geological Survey (USGS) computer code, NETPATH,
was used to interpret probable net geochemical mass-balance reactions that potentially have occurred within the PRB Aquifer
along groundwater flowpaths from bolson margin to bolson center. For all four upgradient–downgradient well pairs studied,
at least three NETPATH models contain cation exchange values; calcium is being exchanged for sodium. The Rio Grande Alluvium
Aquifer and Rio Grande River are notably minor sources of recharge to the PRB Aquifer, based on Chowdhury et al. (2008) and geochemical evaluations of this study. 相似文献
7.
Analyses of the United States Geological Survey geochemical exploration reference samples (GXR) 1–6 are reported for 36 elements and compared with published values. 相似文献
8.
9.
In Alborz Mountains, the thickness of sediments in Member 2 of the Mila Formation (Middle Cambrian) underwent dramatic and
abrupt deformations, which were accompanied by normal and reverse faults and asymmetrical folds. These deformed sediments
are covered by parallel beds both in the upper and lower sides. The existence of such extension and compression structures
adjacent to each other indicates the influence of non-tectonic factors in their evolution. These deformations induced by downslope
gliding of sediment packages are fully compatible with the dislocation model of Farrell (J Struct Geol 6:727–736, 1984) and Farrell and Eaton (1987). Moreover, the occurrence of synsedimentary deformations in a vast area in Alborz Mountains reinforces the probability of
the impact of seismic shocks in their formation. In fact, incessant seismic events in the Middle Cambrian led to numerous
submarine slumpings in the sediments of Member 2 of the Mila Formation. 相似文献
10.
Robert C. Vorhis 《International Journal of Earth Sciences》1955,43(1):47-52
Two types of quantitative hydrologic data resulting from earthquakes have been recorded in recent years in the United States. Both types unquestionably are caused by earthquakes, but as yet neither one can be interpreted rigorously.Publication authorized by the Director, United States Geological Survey. 相似文献
11.
Climate change,environmental degradation and migration 总被引：1，自引：0，他引：1
Climate change will have a progressively increasing impact on environmental degradation and environmentally dependent socio-economic
systems with potential to cause substantial population displacement. The key concerns in Less Developed Countries (LDCs) will
include serious threats to food security and health, considerable economic decline, inundation of coastal areas, and degradation
of land and fresh water resources (Reuveny in Polit Geogr, 2007). The relationship between environmental change and potential humanitarian crises has been captured by: McGregor (Geography
and refugees: patterns and processes of change, Belhaven Press, London, pp 159–70, 1993), Kibreab (Environment and Population Change, International Union for the Scientific Study of Population, Liège, 1994), Kibreab (Disasters 21(1):20–38, 1997), Myers (Bioscience 43:752–761, 1993), Myers and Kent (Environmental exodus: an emergent crisis in the global arena, Climate Institute, Washington, DC, 1995), Black (New Issues in Refugee Research, Working Paper no. 34, 2001), Lee (Environmental matters: conflict, refugees and international relations, World Human Development Institute Press, Seoul
and Tokyo, 2001), Castles (Environmental Change and Induced Migration: Making Sense of the Debate Working Paper No. 70, 2002), Christian Aid (Human tide: the real migration crisis, Christian Aid, London, 2007), and Massey et al. (, 2007). However, we know little about the interplay between environmental change and stresses on ecological systems, resulting
socio-economic vulnerability and potential outcomes in terms of population displacement or induced migration. So far these
relationships are poorly conceptualized, lack systematic investigation, and are reduced to simplistic causal explanations.
This leads to misleading conclusions that deny the complex multivariate processes—environmental, political, social, and economic—
which are the root causes of environmentally induced migration and/or conflict. When people are faced with severe environmental
degradation they have one of three options: (1) stay and adapt to mitigate the effects; (2) stay, do nothing and accept a
lower quality of life; or (3) leave the affected area. The process of movement and migration is usually subject to a complex
set of push and pull forces, where push forces relate to the source area while pull factors relate to the destination. These
forces are in constant flux, as much as environmental change, and interact with socio-economic and political conditions including
state or government decision making powers, which can tip the balance at any point by either denying movement or the right
to settle elsewhere. The paper focuses on how environmental change and environmental hazards contribute to the migration by
exploring the mechanisms through which vulnerability and migration are linked—via livelihoods, relocation policies, and other
factors. The paper begins by outlining important definitions of what is environmentally induced migration. The paper also
considers the question of whether migration is a process that reduces or increases vulnerability. The paper draws on multidisciplinary
literature including ecology, environment, and climate change; sociology of migration; anthropology of displacement; and economics;
but also on preliminary from various case studies in Egypt, Vietnam, and Mozambique. 相似文献
12.
Ellen Hostetter 《GeoJournal》2010,75(3):283-298
This paper analyzes racialization—the social construction of ‘race’ as a normative dimension of everyday life—and shows that
emotion plays a central role in this process. My focus is the representation of post-World War II public housing, a key site
of white-black racialization in the United States. Representations of filth, decay, and danger separate African-Americans
from mainstream, white society as disturbingly different. I argue that this particular representation carries heavy emotional
value, specifically that of disgust and fear. It is disgust and fear that racializes this landscape, giving meaning and force
to an ideology that views African–Americans as inherently inferior to whites. Policy is framed by these emotions, impacting
decisions made about public housing. I explore these ideas through contemporary representations of public housing by federal
officials in Washington, DC and by newspapers in Charlotte, North Carolina as well as the federal program HOPE VI. 相似文献
13.
Suzanne B. Bricker Fred T. Mackenzie Jill S. Baron Jason R. Price 《Aquatic Geochemistry》2014,20(2-3):81-86
This special volume of aquatic geochemistry is dedicated to the memory of Owen Peterson Bricker III (1936–2011) and serves as a tribute to his life and career. Owen had a distinguished and productive research career in both academics at Johns Hopkins University (Fig. 1) and as a public servant with the Maryland Geological Survey, the US Environmental Protection Agency, and the US Geological Survey. He was a pioneer and leader in aqueous geochemistry, who applied a study approach that quantified mineral weathering reactions and equilibrium thermodynamic relations to better understand the chemical evolution of stream water in small watersheds. He will be especially remembered for his efforts to establish rigorous field studies in small catchments around the United States as a means of quantifying the sources of acid-neutralizing capacity that affect the chemical status and biological health of natural waters. Fig. 1
Owen in a Johns Hopkins University laboratory in the early years (~1965, note the tie!) 相似文献
14.
《Applied Geochemistry》2004,19(2):257-260
Over the past 30 a, regional and national solid-phase geochemical surveys have been conducted by the United States Geological Survey and the Geological Survey of Canada. In the present paper the authors have examined the distribution of As in stream-sediment and soil samples of the US and Canada in terms of geologic and anthropogenic components. The results of the compilations indicate that the distribution of As in stream sediments, lake sediments, and soils in Canada and the US shows that most of the variability is controlled by the bed rock characteristics. 相似文献
15.
Sebastiano Imposa 《Environmental Geology》2008,55(5):1061-1073
In this study 50 seismic events, preceding and accompanying the eruptions occurring in 1981 and 1983, have been considered.
Seismic moments, fault radii, stress drops and seismic energies have been calculated using Brune’s model (J Geophys Res 75:4997–5009,
1970; J Geophys Res 76:5002, 1971); site, anelastic attenuation along the propagation path, geometrical spreading and interaction with the free surface effects
are taken into account. For each event we have also estimated the equivalent Wood–Anderson magnitude (MWAeq) (Scherbaum and
Stoll in Bull Seism Soc Am 73:1321–1343, 1983); relations among all these source parameters have been determined. Furthermore, the hypothesis of self-similarity (Aki in
J Geophys Res 72:1217–1231, 1967) is not verified for events with seismic moments <1012 N-m: in fact the relationship between log-stress drop and log-moment is linear up to a moment of 1012 N-m (events of 1981 eruption), while for higher moments (events of 1983 eruption) the slope of the regression line is not
significantly different from zero. We suppose that such a behaviour is related to a heterogeneous medium with barriers on
the faults. Finally, the main conclusion is that eruptions of 1981 and 1983 differ from one another both in eruptive and seismic
aspects; analysis of seismic energies indicates an increase in Mt. Etna’s activity, confirmed by studies performed on the
following lateral eruption of 1991–1993 (Patanè et al. in Bull Volcanol 47:941–952, 1995), occurring on the same structural trend. 相似文献
16.
This article presents probabilistic seismic hazard analyses of northern Pakistan region carried out to produce macro-seismic hazard maps for the region that define new regional ground motion design parameters for 95-, 475-, 975- and 2475-year return period earthquakes as regional contour maps and horizontal uniform hazard at important cities. The Cornell–McGuire approach (Cornell in Bull Seismol Soc Am 58(05):1583–1606, 1968; McGuire in FORTRAN computer program for seismic risk analysis. US Geological Survey, Open file Report, 76-6768, 1976) is used to carry out the analyses at 0.1° rectangular grid. The seismotectonic model of the region used in analysis consists of shallow and deep area zones differentiated based on the focal depths of the earthquakes. Earthquake catalogue compiled and used in the analysis is a composite catalogue composed of 19,373 events. Ground motion prediction equations (GMPEs) used are calibrated using goodness-of-fitness measures and visual inspection with local strong motion data. Epistemic uncertainty in the GMPEs is taken into account through the logic tree approach. Comparison of ground motions due to deep earthquakes is made for the first time for the region. The comparison between ground motion due to shallow and deep earthquakes indicates that the seismic hazard would be underestimated if the deep earthquakes are excluded. Ground motion values obtained in this study considering all the earthquakes suggest ground motions are dominant towards the north east of the region. The proposed study indicates that the ground motion hazard values suggested by the current Building Code of Pakistan underestimate the seismic hazard. Final results of this study are in close agreement with the recent studies on the region. 相似文献
17.
This paper presents the findings of a collaborative research project of the Geological Survey of Lower Saxony (NLfB) and the Programme Group Systems Analysis and Technology Evaluation (STE) of Research Centre Jülich on the GIS-based determination of the mean long-term groundwater recharge in Lower Saxony using high-resolution digital data (Dörhöfer and others 2001). The model calculations were performed on the basis of the water-balance model GROWA (Kunkel and Wendland 2002) with a spatial resolution of 100x100 m2. The accuracy of the calculated groundwater recharge values for the period 1961–1990 was verified on the basis of data from gauging stations and displayed a good agreement between observed runoff values and model results. 相似文献
18.
David H. Oppenheimer Alex N. Bittenbinder Barbara M. Bogaert Raymond P. Buland Lynn D. Dietz Roger A. Hansen Stephen D. Malone Charles S. McCreery Thomas J. Sokolowski Paul M. Whitmore Craig S. Weaver 《Natural Hazards》2005,35(1):59-72
In 1997, the Federal Emergency Management Agency (FEMA), National Oceanic and Atmospheric Administration (NOAA), U.S. Geological Survey (USGS), and the five western States of Alaska, California, Hawaii, Oregon, and Washington joined in a partnership called the National Tsunami Hazard Mitigation Program (NTHMP) to enhance the quality and quantity of seismic data provided to the NOAA tsunami warning centers in Alaska and Hawaii. The NTHMP funded a seismic project that now provides the warning centers with real-time seismic data over dedicated communication links and the Internet from regional seismic networks monitoring earthquakes in the five western states, the U.S. National Seismic Network in Colorado, and from domestic and global seismic stations operated by other agencies. The goal of the project is to reduce the time needed to issue a tsunami warning by providing the warning centers with high-dynamic range, broadband waveforms in near real time. An additional goal is to reduce the likelihood of issuing false tsunami warnings by rapidly providing to the warning centers parametric information on earthquakes that could indicate their tsunamigenic potential, such as hypocenters, magnitudes, moment tensors, and shake distribution maps. New or upgraded field instrumentation was installed over a 5-year period at 53 seismic stations in the five western states. Data from these instruments has been integrated into the seismic network utilizing Earthworm software. This network has significantly reduced the time needed to respond to teleseismic and regional earthquakes. Notably, the West Coast/Alaska Tsunami Warning Center responded to the 28 February 2001 Mw 6.8 Nisqually earthquake beneath Olympia, Washington within 2 minutes compared to an average response time of over 10 minutes for the previous 18 years. 相似文献
19.
Attenuation relationships are commonly used for engineering studies to estimate the peak ground acceleration values. This
paper presents the role of attenuation relationship in defining the seismic hazard in an area. It is seen that the seismic
hazard in an area, which is calculated using attenuation relationships, is mostly controlled by the type of attenuation relationship
used in the study. The present work aims to study the effect of attenuation relationship on seismic hazard study. In the present
work, seismic hazard maps have been prepared in the seismically very active northeast Himalaya using the approach given by
Joshi and Patel (Tectonophysics 283:289–310, 1997). The attenuation relationships of Jain et al. (2000), Sharma (2000), Joyner and Boore (Bull Seism Soc Am 71:2011–2038, 1981) and Abrahamson and Litehiser (Bull Seism Soc Am 79:549–580, 1989) have been considered in the present study. Among all considered attenuation relationships, the Abrahamson and Litehiser
(Bull Seism Soc Am 79:549–580, 1989) attenuation relationship gives the least root mean square error between the recorded and calculated peak ground acceleration
values. Therefore, the same has been used to define attenuation characteristic of the region. The mean and standard deviation
of peak ground acceleration values at all the observation points due to above-mentioned attenuation relationships in the NE
Himalayas are calculated. The study shows that the Zone III covers an area of 81,000 km2 and Zone II of 96,000 km2 in the map prepared using the mean peak ground acceleration values, whereas the area of Zone IV increases by 40,000 km2 when the map is prepared by adding the standard deviation values in the mean peak ground acceleration values, and only Zone
II is left with 183,000 km2 when the standard deviation values are subtracted from the mean. This high standard deviation is due to the difference in
the peak ground acceleration values obtained from different events. This study shows that a rigorous test needs to be done
for selecting attenuation relationship for any hazard study in a given area. 相似文献
20.
Phenocrysts of sodic sanidine from twelve upper Cenozoic units of silicic ash-flow tuff and lava from the Western United States contain from 0.25 to 0.45 the Rb present in the associated groundmass materials. The ratios of potassium to rubidium in the sanidines are, on the average, about four times greater than those of the groundmass. Separation of phenocrystic sanidine from salic melts provides an efficient method for raising the Rb content and lowering the K/Rb ratio of the melts, although the amount of differentiation probably is limited by continuous reequilibration of the alkalis between crystal and liquid phases through ion exchange. Syenites of cumulate origin will have appreciably lower Rb contents and higher K/Rb ratios than the melts from which they precipitated. Available data on the distribution of Rb between synthetic biotite and K-sanidine demonstrate that the separation of biotite probably will not deplete salic melts in Rb relative to K.Publication authorized by the Director, U.S. Geological Survey.On leave from the Department of Geological Sciences, Harvard University. 相似文献