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141.
Probabilistic seismic hazard assessment for Thailand 总被引:3,自引:1,他引:2
Teraphan Ornthammarath Pennung Warnitchai Kawin Worakanchana Saeed Zaman Ragnar Sigbj?rnsson Carlo Giovanni Lai 《Bulletin of Earthquake Engineering》2011,9(2):367-394
A set of probabilistic seismic hazard maps for Thailand has been derived using procedures developed for the latest US National
Seismic Hazard Maps. In contrast to earlier hazard maps for this region, which are mostly computed using seismic source zone
delineations, the presented maps are based on the combination of smoothed gridded seismicity, crustal-fault, and subduction
source models. Thailand’s composite earthquake catalogue is revisited and expanded, covering a study area limited by 0°–30°N
Latitude and 88°–110°E Longitude and the instrumental period from 1912 to 2007. The long-term slip rates and estimates of
earthquake size from paleoseismological studies are incorporated through a crustal fault source model. Furthermore, the subduction
source model is used to model the megathrust Sunda subduction zones, with variable characteristics along the strike of the
faults. Epistemic uncertainty is taken into consideration by the logic tree framework incorporating basic quantities, such
as different source modelling, maximum cut-off magnitudes and ground motion prediction equations. The ground motion hazard
map is presented over a 10 km grid in terms of peak ground acceleration and spectral acceleration at 0.2, 1.0, and 2.0 undamped
natural periods and a 5% critical damping ratio for 10 and 2% probabilities of exceedance in 50 years. The presented maps
give expected ground motions that are based on more extensive data sources than applied in the development of previous maps.
The main findings are that northern and western Thailand are subjected to the highest hazard. The largest contributors to
short- and long-period ground motion hazard in the Bangkok region are from the nearby active faults and Sunda subduction zones,
respectively. 相似文献
142.
M. Coltorti R. Boraso M. Morsilli A. Riva R. Tassinari G. Di Carlo 《Geochimica et cosmochimica acta》2011,75(9):2271-2294
The regional contribution to the geo-neutrino signal at Gran Sasso National Laboratory (LNGS) was determined based on a detailed geological, geochemical and geophysical study of the region. U and Th abundances of more than 50 samples representative of the main lithotypes belonging to the Mesozoic and Cenozoic sedimentary cover were analyzed. Sedimentary rocks were grouped into four main “reservoirs” based on similar depositional settings and mineralogy. The initial assumption that similar chemico-physical depositional conditions would lead to comparable U and Th contents, was then confirmed by chemical analyses. Basement rocks do not outcrop in the area. Thus U and Th in the upper and lower crust of Valsugana and Ivrea-Verbano areas were analyzed. Irrespective of magmatic or metamorphic origin lithotypes were subdivided into a mafic and an acid reservoir, with comparable U and Th abundances.Based on geological and geophysical properties, relative abundances of the various reservoirs were calculated and used to obtain the weighted U and Th abundances for each of the three geological layers (sedimentary cover, upper and lower crust). Using the available seismic profile as well as the stratigraphic records from a number of exploration wells, a 3D modeling was developed over an area of 2° × 2° down to the Moho depth, for a total volume of about 1.2 × 106 km3. This model allowed us to determine the volume of the various geological layers and eventually integrate the Th and U contents of the whole crust beneath LNGS.On this base the local contribution to the geo-neutrino flux (S) was calculated and added to the contribution given by the rest of the world, yielding a refined reference model prediction for the geo-neutrino signal in the Borexino detector at LNGS: S(U) = (28.7 ± 3.9) TNU and S(Th) = (7.5 ± 1.0) TNU. An excess over the total flux of about 4 TNU was previously obtained by Mantovani et al. (2004) who calculated, based on general worldwide assumptions, a signal of 40.5 TNU. The considerable thickness of the sedimentary rocks, almost predominantly represented by U- and Th-poor carbonatic rocks in the area near LNGS, is responsible for this difference. Thus the need for detailed integrated geological study is underlined by this work, if the usefulness of the geo-neutrino flux for characterizing the global U and Th distribution within the Earth’s crust, mantle and core is to be realized. 相似文献
143.
Ecosystem-based marine spatial management: Review of concepts, policies, tools, and critical issues 总被引:1,自引:0,他引:1
Stelios Katsanevakis Vanessa Stelzenmüller Andy South Thomas Kirk Sørensen Peter J.S. Jones Sandy Kerr Fabio Badalamenti Christos Anagnostou Patricia Breen Guillem Chust Giovanni D’Anna Mike Duijn Tatiana Filatova Fabio Fiorentino Helena Hulsman Kate Johnson Aristomenis P. Karageorgis Ingrid Kröncke Simone Mirto Carlo Pipitone Susan Portelli Wanfei Qiu Henning Reiss Dimitris Sakellariou Maria Salomidi Luc van Hoof Vassiliki Vassilopoulou Tomás Vega Fernández Sandra Vöge Anke Weber Argyro Zenetos Remment ter Hofstede 《Ocean & Coastal Management》2011,54(11):807-820
Conventional sectoral management and piecemeal governance are considered less and less appropriate in pursuit of sustainable development. Ecosystem based marine spatial management (EB-MSM) is an approach that recognizes the full array of interactions within an ecosystem, including human uses, rather than considering single issues, species, or ecosystem services in isolation. Marine spatial planning and ocean zoning are emerging concepts that can support EB-MSM. EB-MSM is driven by high-level goals that managers aim to achieve through the implementation of measures. High-level goals and objectives need to be translated into more operational objectives before specific targets, limits and measures can be elaborated.Monitoring, evaluation and adaptation are necessary to ensure that marine management measures are both effective and efficient. Solid monitoring frameworks are the foundation of adaptive management, as they provide the necessary information to evaluate performance and the effectiveness of management actions. Marine protected areas (MPAs) - possibly set up in networks - constitute a key component in EB-MSM policies and practises and have been applied as a cornerstone in conservation of marine biodiversity, management of fish populations, development of coastal tourism, etc. Moreover, MPA experiences have provided methods and concepts (such as zoning) to a wider EB-MSM context. The assignment of values to biophysical features of the marine environment allows the direct assessment of related management choices and may assist EB-MSM.A range of monetary valuation techniques have been proposed to reduce attributes of goods and services to a single metric. However, in the marine environment such an approach is often over simplistic, and thus less reductive techniques may be necessary. Rather than producing a single metric, the results of non-monetary assessments guide policy allowing weight to be given as necessary to potential areas of conflict and consensus.Strategies to take into account climate change effects and geohazard risks in EB-MSM have been applied or proposed worldwide. EB-MSM regimes must be alert to such risks and flexible to account for changes. 相似文献
144.
Carlo Montes Ricardo C. Muñoz Jorge F. Perez-Quezada 《Theoretical and Applied Climatology》2013,111(1-2):275-284
This paper analyzes the influence of circulation anomalies on the magnitude of minimum air temperature (T min) at a daily scale in two important agricultural valleys of Chile (Maipo and Casablanca) during the period 2001–2007. A statistical classification of synoptic fields was performed, resulting in eight circulation patterns (CPs, 84 % of explained variance). The corresponding anomalies of T min (ATmin) of each CP were analyzed in order to understand their synoptic-scale forcing mechanisms. Results showed a direct association between ATmin and the synoptic structure. The average weakening in sea level pressure (SLP) yields positive ATmin, while negative ATmin is associated with a strengthening in SLP. In the latter case, it was also found that a synoptic structure (10.2 % of frequency) corresponding to a migratory high-pressure system passing eastward across the Andes led to the lowest ATmin and a higher probability of frost in both valleys (22 % on average) in winter and springtime. 相似文献
145.
On the equations of the dynamics of the attracting point masses 相似文献
146.
We evaluate the expected level of foreground contamination to the cosmic microwave background (CMB) polarised radiation, focusing on the diffuse emission from our own Galaxy. In particular, we perform a first attempt to simulate an all sky template of polarised emission from thermal dust. This study indicates that the foreground contamination to CMB B-modes is likely to be relevant on all frequencies, and even at high Galactic latitudes. We review the recent developments in the design of data analysis techniques dedicated to the separation of CMB and foreground emissions in multi-frequency observations, exploiting their statistical independence. We argue that the high quality and detail of the present CMB observations represent an almost ideal statistical dataset where these algorithms can operate with excellent performance. We explicitly show that the recovery of CMB B-modes is possible even if they are well below the foreground level, working at the arcminute resolution at an almost null computational cost. This capability well represents the great potentiality of these new data analysis techniques, which should be seriously taken into account for implementation in present and future CMB observations. 相似文献
147.
Parolai Stefano Lai Carlo G. Dreossi Ilaria Ktenidou Olga-Joan Yong Alan 《Journal of Seismology》2022,26(4):823-862
Journal of Seismology - Seismic attenuation and the associated quality factor (Q) have long been studied in various sub-disciplines of seismology, ranging from observational and engineering... 相似文献
148.
Cauzzi Carlo Fäh Donat Wald David J. Clinton John Losey Stéphane Wiemer Stefan 《Natural Hazards》2018,92(2):1211-1235
Natural Hazards - In Switzerland, nearly all historical Mw?~?6 earthquakes have induced damaging landslides, rockslides and snow avalanches that, in some cases, also resulted in damage... 相似文献
149.
Is the westerly rotation of the lithosphere an ephemeral accidental recent phenomenon or is it a stable process of Earth's geodynamics? The reason why the tidal drag has been questioned as the mechanism determining the lithospheric shift relative to the underlying mantle is the apparent too high viscosity of the asthenosphere. However, plate boundaries asymmetries are a robust indication of the ‘westerly’ decoupling of the entire Earth's outer lithospheric shell and new studies support lower viscosities in the low-velocity layer (LVZ) atop the asthenosphere. Since the solid Earth tide oscillation is longer in one side relative to the other due to the contemporaneous Moon's revolution, we demonstrate that a non-linear rheological behavior is expected in the lithosphere mantle interplay. This may provide a sort of ratchet favoring lowering of the LVZ viscosity under shear, allowing decoupling in the LVZ and triggering the westerly motion of the lithosphere relative to the mantle. 相似文献
150.
Investigating the association between streetscapes and human walking activities using Google Street View and human trajectory data 总被引:1,自引:0,他引:1 下载免费PDF全文
Xiaojiang Li Paolo Santi Theodore K. Courtney Santosh K. Verma Carlo Ratti 《Transactions in GIS》2018,22(4):1029-1044
Having an active lifestyle is recognized to positively contribute to public health. Creating more walkable streets and neighborhoods is an important way to promote an active lifestyle for urban residents. It is therefore important to understand how the urban built environment can influence human walking activities. In this study, we investigated the interaction of human walking activities and physical characteristics of streetscapes in Boston. A large number of anonymous pedestrian trajectories collected from a smartphone application were used to estimate human walking activities. Publicly accessible Google Street View images were used to estimate the amount of street greenery and the enclosure of street canyons, both of which were used to indicate the physical characteristics of streetscapes. The Walk Score and population were also added in the statistical analyses to control the influence of nearby urban facilities and population on human walking activities. Statistical analysis results show that both the street greenery and the enclosure of the street canyons are significantly associated with human walking activities. The associations between the streetscape variables and human walking activities vary in different land use types. The results of this study have implications for designing walkable and healthy cities. 相似文献