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981.
The 2013 European Seismic Hazard Model: key components and results 总被引:11,自引:5,他引:6
Jochen Woessner Danciu Laurentiu Domenico Giardini Helen Crowley Fabrice Cotton Gottfried Grünthal Gianluca Valensise Ronald Arvidsson Roberto Basili Mine Betül Demircioglu Stefan Hiemer Carlo Meletti Roger W. Musson Andrea N. Rovida Karin Sesetyan Massimiliano Stucchi The SHARE Consortium 《Bulletin of Earthquake Engineering》2015,13(12):3553-3596
982.
Albert Casas Pietro L. Cosentino Gianluca Fiandaca Mahjoub Himi Josep M. Macias Raffaele Martorana Andreu Muñoz Lluís Rivero Roger Sala Imma Teixell 《Surveys in Geophysics》2018,39(6):1107-1124
An integrated geophysical survey has been conducted at the Tarragona’s Cathedral (Catalonia, NE Spain) with the aim to confirm the potential occurrence of archaeological remains of the Roman Temple dedicated to the Emperor Augustus. Many hypotheses have been proposed about its possible location, the last ones regarding the inner part of the Cathedral, which is one of the most renowned temples of Spain (twelfth century) evolving from Romanesque to Gothic styles. A geophysical project including electrical resistivity tomography (ERT) and ground probing radar (GPR) was planned over 1 year considering the administrative and logistic difficulties of such a project inside a cathedral of religious veneration. Finally, both ERT and GPR have been conducted during a week of intensive overnight surveys that provided detailed information on subsurface existing structures. The ERT method has been applied using different techniques and arrays, ranging from standard Wenner–Schlumberger 2D sections to full 3D electrical imaging with the advanced Maximum Yield Grid array. Electrical resistivity data were recorded extensively, making available many thousands of apparent resistivity data to obtain a complete 3D image after a full inversion. In conclusion, some significant buried structures have been revealed providing conclusive information for archaeologists. GPR results provided additional information about shallowest structures. The geophysical results were clear enough to persuade religious authorities and archaeologists to conduct selected excavations in the most promising areas that confirmed the interpretation of geophysical data. In conclusion, the significant buried structures revealed by geophysical methods under the cathedral were confirmed by archaeological digging as the basement of the impressive Roman Temple that headed the Provincial Forum of Tarraco, seat of the Concilium of Hispania Citerior Province. 相似文献
983.
Decomposition algorithms for system reliability estimation with applications to interdependent lifeline networks
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Reliability and risk assessment of lifeline systems call for efficient methods that integrate hazard and interdependencies. Such methods are computationally challenged when the probabilistic response of systems is tied to multiple events, as performance quantification requires a large catalog of ground motions. Available methods to address this issue use catalog reductions and importance sampling. However, besides comparisons against baseline Monte Carlo trials in select cases, there is no guarantee that such methods will perform or scale well in practice. This paper proposes a new efficient method for reliability assessment of interdependent lifeline systems, termed RAILS, that considers systemic performance and is particularly effective when dealing with large catalogs of events. RAILS uses the state‐space partition method to estimate systemic reliability with theoretical bounds and, for the first time, supports cyclic interdependencies among lifeline systems. Recycling computations across an entire seismic catalog with RAILS considerably reduces the number of system performance evaluations in seismic performance studies. Also, when performance estimate bounds are not tight, we adopt an importance and stratified sampling method that in our computational experiments is various orders of magnitude more efficient than crude Monte Carlo. We assess the efficiency of RAILS using synthetic networks and illustrate its application to quantify the seismic risk of realistic yet streamlined systems hypothetically located in the San Francisco Bay Region. 相似文献
984.
Sediment detachment and transport processes associated with internal erosion of soil pipes
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Subsurface flow can be an important process in gully erosion through its impact on decreasing soil cohesion and erosion resistance as soil water content or pressure increases and more directly by the effects of seepage forces on particle detachment and piping. The development of perched water tables fosters lateral flow that can result in seepage at the surface and/or formation of soil pipes by internal erosion of preferential flow paths. Continued internal erosion of soil pipes can lead to gullies, dam and levee failures. However, the processes involved in particle and aggregate detachment from soil pipe walls and transport processes within soil pipes have not been well studied or documented. This paper reviews the limited research on sediment detachment and transport in macropores and soil pipes and applies the knowledge learned from the much more extensive studies conducted on streams and industrial pipes to hydrogeologic conditions of soil pipes. Knowledge gaps are identified and recommendations are made for future research on sediment detachment and transport in soil pipes. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
985.
Marine control over negative power law scaling of mass wasting events in chalk sea cliffs with implications for future recession under the UKCP09 medium emission scenario
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Coastal cliff erosion represents a significant geohazard for people and infrastructure. Forecasting future erosion rates is therefore of critical importance to ensuring the resiliency of coastal communities. We use high precision monitoring of chalk cliffs at Telscombe, UK to generate monthly mass movement inventories between August 2016 and July 2017. Frequency–magnitude analysis of our inventories demonstrate negative power law scaling over 7 orders of magnitude and, for the first time, we report statistically significant correlations between significant wave height (Hs) and power law scaling coefficients (r2 values of 0.497 and 0.590 for β and s respectively). Applying these relationships allows for a quantitative method to predict erosion at the site based on Hs probabilities and sea level forecasts derived from the UKCP09 medium emission climate model (A1B). Monte‐Carlo simulations indicate a range of possible erosion scenarios over 70 years (2020–2090) and we assess the impact these may have on the A259 coastal road which runs proximal to the cliffs. Results indicate a small acceleration in erosion compared with those based on current conditions with the most likely scenario at the site being 21.7 m of cliff recession by 2090. However, low‐probability events can result in recession an order of magnitude higher in some scenarios. In the absence of negative feedbacks, we estimate an ~11% chance that the A259 will be breached by coastal erosion by 2090. Copyright © 2018 John Wiley & Sons, Ltd. 相似文献
986.
Pedretti Daniele Mayer K. Ulrich Beckie Roger D. 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(1):219-233
Stochastic Environmental Research and Risk Assessment - Heterogeneity in waste rock piles (WRPs) determines uncertainty in acid mine drainage (ARD) predictions from these deposits. Numerical... 相似文献
987.
Marengo Jose A. Cunha Ana Paula M. A. Nobre Carlos A. Ribeiro Neto Germano G. Magalhaes Antonio R. Torres Roger R. Sampaio Gilvan Alexandre Felipe Alves Lincoln M. Cuartas Luz A. Deusdará Karinne R. L. Álvala Regina C. S. 《Natural Hazards》2020,103(2):2589-2611
Natural Hazards - Historically, during periods of extreme drought, food security in the drylands of the semiarid region of Northeast Brazil (NEB) is under severe risk due to agricultural collapse.... 相似文献
988.
Roger M. Jacobi Peter J. Rowe Mabs A. Gilmour Rainer Grün Timothy C. Atkinson 《第四纪科学杂志》1998,13(1):29-42
Uranium-series dating of derived speleothem suggests that the sediments enclosing a Middle Palaeolithic stone artefact assemblage in Pin Hole Cave probably accumulated after about 64 ka, and 14C dates indicate a likely age of > 40 ka for the large mammal fauna associated with it. Electron spin resonance data from the fauna conform with these age constraints and are consistent with accumulation between 38 and 50 ka. This evidence supports the view that Britain was recolonised by hominids during Oxygen Isotope Stage 3. Stratigraphically higher stone tool industries demonstrate the local presence of both early Upper and late Upper Palaeolithic cultures. © 1998 John Wiley & Sons, Ltd. 相似文献
989.
Peter H. Edwards John C. Bridges Roger Wiens Ryan Anderson Darby Dyar Martin Fisk Lucy Thompson Patrick Gasda Justin Filiberto Susanne P. Schwenzer Diana Blaney Ian Hutchinson 《Meteoritics & planetary science》2017,52(11):2931-2410
The ChemCam instrument on the Mars Science Laboratory (MSL) rover, Curiosity, observed numerous igneous float rocks and conglomerate clasts, reported previously. A new statistical analysis of single‐laser‐shot spectra of igneous targets observed by ChemCam shows a strong peak at ~55 wt% SiO2 and 6 wt% total alkalis, with a minor secondary maximum at 47–51 wt% SiO2 and lower alkali content. The centers of these distributions, together with the rock textures, indicate that many of the ChemCam igneous targets are trachybasalts, Mg# = 27 but with a secondary concentration of basaltic material, with a focus of compositions around Mg# = 54. We suggest that all of these igneous rocks resulted from low‐pressure, olivine‐dominated fractionation of Adirondack (MER) class‐type basalt compositions. This magmatism has subalkaline, tholeiitic affinities. The similarity of the basalt endmember to much of the Gale sediment compositions in the first 1000 sols of the MSL mission suggests that this type of Fe‐rich, relatively low‐Mg#, olivine tholeiite is the dominant constituent of the Gale catchment that is the source material for the fine‐grained sediments in Gale. The similarity to many Gusev igneous compositions suggests that it is a major constituent of ancient Martian magmas, and distinct from the shergottite parental melts thought to be associated with Tharsis and the Northern Lowlands. The Gale Crater catchment sampled a mixture of this tholeiitic basalt along with alkaline igneous material, together giving some analogies to terrestrial intraplate magmatic provinces. 相似文献
990.
Silvana N.R. Birchenough Siân E. BoydKoen Vanstaen Roger A. CogganDavid S. Limpenny 《Estuarine, Coastal and Shelf Science》2010
Each year approximately 23–28 million tonnes of sand and gravel are removed from offshore sediments around England and Wales. This study was located in a licensed marine aggregate extraction site off Shoreham in the Eastern English Channel (EEC thereafter). Results from the multibeam survey showed the presence of dredged pits created by suction hopper dredging and elongated furrows created by trailer suction hopper dredging in the area where sand and gravel had been excavated. Electronic Monitoring System (EMS) contained the dredging intensity recorded annually at the site; this information was combined with particle size data providing interpreted maps, which informed the status of the sediments at the site. 相似文献