321 research outputs found
COMPILATION OF ACTIVE FAULT DATA IN PORTUGAL FOR USE IN SEISMIC HAZARD ANALYSIS
To estimate where future earthquakes are likely to occur, it is essential to combine information about past earthquakes with knowledge about the location and seismogenic properties of active faults. For this reason, robust probabilistic seismic hazard analysis (PSHA) integrates seismicity and active fault data. Existing seismic hazard assessments for Portugal rely exclusively on seismicity data and do not incorporate data on active faults. Project SHARE (Seismic Hazard Harmonization in Europe) is an EC-funded initiative (FP7) that aims to evaluate European seismic hazards using an integrated, standardized approach. In the context of SHARE, we are developing a fully-parameterized active fault database for Portugal that incorporates existing compilations, updated according to the most recent publications. The seismogenic source model derived for SHARE will be the first model for Portugal to include fault data and follow an internationally standardized approach. This model can be used to improve both seismic hazard and risk analyses and will be combined with the Spanish database for use in Iberian- and European-scale assessments
Kaluza-Klein Type Robertson Walker Cosmological Model With Dynamical Cosmological Term
In this paper we have analyzed the Kaluza-Klein type Robertson Walker (RW)
cosmological models by considering three different forms of variable :
, and
. It is found that, the connecting free parameters of the
models with cosmic matter and vacuum energy density parameters are equivalent,
in the context of higher dimensional space time. The expression for the look
back time, luminosity distance and angular diameter distance are also derived.
This work has thus generalized to higher dimensions the well-known results in
four dimensional space time. It is found that there may be significant
difference in principle at least, from the analogous situation in four
dimensional space time.Comment: 16 pages, no figur
Generation of Bianchi type V cosmological models with varying -term
Bianchi type V perfect fluid cosmological models are investigated with
cosmological term varying with time. Using a generation technique
(Camci {\it et al.}, 2001), it is shown that the Einstein's field equations are
solvable for any arbitrary cosmic scale function. Solutions for particular
forms of cosmic scale functions are also obtained. The cosmological constant is
found to be decreasing function of time, which is supported by results from
recent type Ia supernovae observations. Some physical aspects of the models are
also discussed.Comment: 16 pages, 3 figures, submitted to CJ
Compilation of parameterized seismogenic sources in Iberia for the SHARE European-scale seismic source model.
Abstract: SHARE (Seismic Hazard Harmonization in Europe) is an EC-funded project (FP7) that aims to evaluate European seismic hazards using an integrated, standardized approach. In the context of SHARE, we are compiling a fully-parameterized active fault database for Iberia and the nearby offshore region. The principal goal of this initiative is for fault sources in the Iberian region to be represented in SHARE and incorporated into the source model that will be used to produce seismic hazard maps at the European scale. The SHARE project relies heavily on input from many regional experts throughout the Euro-Mediterranean region. At the SHARE regional meeting for Iberia, the 2010 Working Group on Iberian Seismogenic Sources (WGISS) was established; these researchers are contributing to this large effort by providing their data to the Iberian regional integrators in a standardized format. The development of the SHARE Iberian active fault database is occurring in parallel with IBERFAULT, another ongoing effort to compile a database of active faults in the Iberian region.
The SHARE Iberian active fault database synthesizes a wide range of geological and geophysical observations on active seismogenic sources, and incorporates existing compilations (e.g., Cabral, 1995; Silva et al., 2008), original data contributed directly from researchers, data compiled from the literature, parameters estimated using empirical and analytical relationships, and, where necessary, parameters derived using expert judgment. The Iberian seismogenic source model derived for SHARE will be the first regional-scale source model for Iberia that includes fault data and follows an internationally standardized approach (Basili et al., 2008; 2009). This model can be used in both seismic hazard and risk analyses and will be appropriate for use in Iberian- and European-scale assessments
Plane-symmetric inhomogeneous magnetized viscous fluid universe with a variable
The behavior of magnetic field in plane symmetric inhomogeneous cosmological
models for bulk viscous distribution is investigated. The coefficient of bulk
viscosity is assumed to be a power function of mass density . The values of cosmological constant for these models are
found to be small and positive which are supported by the results from recent
supernovae Ia observations. Some physical and geometric aspects of the models
are also discussed.Comment: 18 pages, LaTex, no figur
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