scholarly journals Sequence-based hazard analysis for Italy considering a grid seismic source model

2021 ◽  
Vol 64 (2) ◽  
Author(s):  
Eugenio Chioccarelli ◽  
Pasquale Cito ◽  
Francesco Visini ◽  
Iunio Iervolino
Keyword(s):  
Earthquake Engineering ◽  
Hazard Analysis ◽  
Seismic Source ◽  
Source Model ◽  
Classical Formulation ◽  
Omori Law ◽  
Model Account ◽  
Before And After ◽  
Seismic Source Model ◽  
Modified Omori Law

Earthquakes are usually clustered in both time and space and, within each cluster, the event of highest magnitude is conventionally identified as the mainshock, while the foreshocks and the aftershocks are the events that occur before and after it, respectively. Mainshocks are the earthquakes considered in the classical formulation of the probabilistic seismic hazard analysis (PSHA), where the contribution of foreshocks and aftershocks is usually neglected. In fact, it has been shown that it is possible to rigorously, within the hypotheses of the model, account for the effect of mainshock-aftershocks sequences by means of the sequence-based PSHA (i.e., SPSHA). SPSHA extends the usability of the homogeneous Poisson process, adopted for mainshocks within PSHA, to also describe the occurrence of clusters maintaining the same input data of PSHA; i.e., the seismic rates derived by a declustered catalog. The aftershocks’ occurrences are accounted for by means of conditional non-homogeneous Poisson processes based on the modified Omori law. The seismic source model for Italy has been recently investigated, and the objective of the study herein presented is to include and evaluate the effect of aftershocks, by means of SPSHA, based on a new grid model. In the paper, the results of PSHA and SPSHA are compared, considering the spectral and return periods that are of typical interest for earthquake engineering. Finally, a comparison with the SPSHA map based on a well- established source model for Italy is also provided.

Seismic source model for moving vehicles

2005 ◽  
Vol 43 (2) ◽  
pp. 248-256 ◽  
Author(s):  
S.A. Ketcham ◽  
M.L. Moran ◽  
J. Lacombe ◽  
R.J. Greenfield ◽  
T.S. Anderson
Keyword(s):  
Seismic Source ◽  
Source Model ◽  
Moving Vehicles ◽  
Seismic Source Model

On the Nature of Logic Trees in Probabilistic Seismic Hazard Assessment

2012 ◽  
Vol 28 (3) ◽  
pp. 1291-1296 ◽  
Author(s):  
Roger Musson
Keyword(s):  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Source Model ◽  
Probabilistic Seismic Hazard Assessment ◽  
Motion Model ◽  
Logic Tree ◽  
Ground Motion Model ◽  
Seismic Source Model ◽  
Kolmogorov Axioms ◽  
Better Than

An objection sometimes made against treating the weights of logic tree branches as probabilities relates to the Kolmogorov axioms, but these are only an obstacle if one believes that logic tree branches represent a seismic source model or ground motion model as being “true.” Models are never true, but some models are better than others. It is argued here that a logic tree weight represents the probability that the model in question is better than the others considered. Only one branch can be the best one, and one branch must be the best one. It is also argued that there are situations in PSHA where uncertainty exists but the analyst lacks the means to express it. Therefore it is not necessarily the case that more information increases uncertainty; it may be that more information increases the possibility of expressing uncertainty that was previously unmanageable.

Developing a seismic source model for the Arabian Plate

2018 ◽  
Vol 11 (15) ◽  
Author(s):  
I. El-Hussain ◽  
Y. Al-Shijbi ◽  
A. Deif ◽  
A. M. E. Mohamed ◽  
M. Ezzelarab
Keyword(s):  
Seismic Source ◽  
Source Model ◽  
Arabian Plate ◽  
Seismic Source Model

scholarly journals Model for Calculating Seismic Wave Spectrum Excited by Explosive Source

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Qian Xu ◽  
Zhong-Qi Wang
Keyword(s):  
Seismic Wave ◽  
Seismic Waves ◽  
Wave Spectrum ◽  
Seismic Source ◽  
Source Model ◽  
Detonation Pressure ◽  
Adiabatic Expansion ◽  
Main Frequency ◽  
Explosive Source ◽  
Seismic Source Model

To reveal the characteristics and laws of the seismic wavefield amplitude-frequency excited by explosive source, the method for computing the seismic wave spectrum excited by explosive was studied in this paper. The model for calculating the seismic wave spectrum excited by explosive source was acquired by taking the seismic source model of spherical cavity as the basis. The results of using this model show that the main frequency and the bandwidth of the seismic waves caused by the explosion are influenced by the initial detonation pressure, the adiabatic expansion of the explosive, and the geotechnical parameters, which increase with the reduction of initial detonation pressure and the increase of the adiabatic expansion. The main frequency and the bandwidth of the seismic waves formed by the detonation of the explosives in the silt clay increase by 23.2% and 13.6% compared to those exploded in the silt. The research shows that the theoretical model built up in this study can describe the characteristics of the seismic wave spectrum excited by explosive in a comparatively accurate way.

Western Mexico seismic source model for the seismic hazard assessment of the Jalisco-Colima-Michoacán region

2020 ◽  
Author(s):  
Rashad Sawires ◽  
Miguel A. Santoyo ◽  
José A. Peláez ◽  
Jesús Henares
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Source Model ◽  
Western Mexico ◽  
Seismic Source Model

scholarly journals Integrated seismic source model of the 2015 Gorkha, Nepal, earthquake

2015 ◽  
Vol 42 (15) ◽  
pp. 6229-6235 ◽  
Author(s):  
Yuji Yagi ◽  
Ryo Okuwaki
Keyword(s):  
Seismic Source ◽  
Source Model ◽  
Nepal Earthquake ◽  
Seismic Source Model ◽  
2015 Gorkha Nepal Earthquake

Tsunami Simulation Using Vertical Displacement Calculated from Simulation of Ground Motion due to Seismic Source Model

2012 ◽  
Vol 12 ◽  
pp. 4_308-4_318
Author(s):  
Shinichi AKIYAMA ◽  
Kaoru KAWAJI ◽  
Mariko KORENAGA ◽  
Satoru FUJIHARA ◽  
Takahiro TAMIYA
Keyword(s):  
Ground Motion ◽  
Seismic Source ◽  
Vertical Displacement ◽  
Source Model ◽  
Tsunami Simulation ◽  
Seismic Source Model

Seismic hazard estimate from background seismicity in southern California

1996 ◽  
Vol 86 (5) ◽  
pp. 1372-1381 ◽  
Author(s):  
Tianqing Cao ◽  
Mark D. Petersen ◽  
Michael S. Reichle
Keyword(s):  
Seismic Hazard ◽  
Southern California ◽  
Seismic Source ◽  
Source Model ◽  
Historical Seismicity ◽  
Rational Approach ◽  
Smoothing Function ◽  
Background Seismicity ◽  
Seismic Source Model ◽  
Seismicity Catalog

Abstract We analyzed the historical seismicity in southern California to develop a rational approach for calculating the seismic hazard from background seismicity of magnitude 6.5 or smaller. The basic assumption for the approach is that future earthquakes will be clustered spatially near locations of historical mainshocks of magnitudes equal to or greater than 4. We analyzed the declustered California seismicity catalog to compute the rate of earthquakes on a grid and then smoothed these rates to account for the spatial distribution of future earthquakes. To find a suitable spatial smoothing function, we studied the distance (r) correlation for southern California earthquakes and found that they follow a 1/rµ power-law relation, where µ increases with magnitude. This result suggests that larger events are more clustered in space than smaller earthquakes. Assuming the seismicity follows the Gutenberg-Richter distribution, we calculated peak ground accelerations (PGA) for 10% probability of exceedance in 50 yr. PGA estimates range between 0.25 and 0.35 g across much of southern California. These ground-motion levels are generally less than half the levels of hazard that are obtained using the entire seismic source model that also includes geologic and geodetic data. We also calculated the overall uncertainty for the hazard map using a Monte Carlo method and found that the coefficient of variation is about 0.24 ± 0.01 for much of the region.

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