Ground motion modelling in the Gujarat region of Western India using empirical Green's function approach

2016 ◽  
Vol 675 ◽  
pp. 7-22 ◽  
Author(s):  
Pallabee Choudhury ◽  
Sumer Chopra ◽  
Ketan Singha Roy ◽  
Jyoti Sharma
Keyword(s):  
Green’S Function ◽  
Ground Motion ◽  
Green's Function ◽  
Function Approach ◽  
Western India ◽  
Empirical Green’S Function ◽  
Ground Motion Modelling ◽  
Empirical Green's Function

Revisiting the 1956 Anjar Earthquake in Western India: Empirical Green’s Function Approach

2017 ◽  
Vol 107 (2) ◽  
pp. 592-602 ◽  
Author(s):  
Pallabee Choudhury ◽  
Sumer Chopra ◽  
Ketan Singha Roy ◽  
Jyoti Sharma ◽  
B. K. Rastogi
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Function Approach ◽  
Western India ◽  
Empirical Green’S Function ◽  
Empirical Green's Function

Reproducing the Spatial Characteristics of High-Frequency Ground Motions for the 1850 M 7.5 Xichang Earthquake

2021 ◽  
Author(s):  
Zongchao Li ◽  
Jize Sun ◽  
Lihua Fang ◽  
Xueliang Chen ◽  
Mengtan Gao ◽  
...  
Keyword(s):  
Green’S Function ◽  
Ground Motion ◽  
Green's Function ◽  
Function Method ◽  
Ground Motions ◽  
Empirical Green’S Function ◽  
Green’S Function Method ◽  
Spatial Characteristics ◽  
Meizoseismal Area ◽  
Empirical Green's Function

Abstract Reproducing the spatial characteristics of large historical earthquakes and predicting the strong ground motions of future destructive large earthquakes through actual small earthquakes have high-practical value. The empirical Green’s function method is a numerical simulation method that can impart real seismic information in synthetic ground motions. In this article, we use data from the 2018 M 5.1 Xichang earthquake to reproduce the ground-motion characteristics of the 1850 M 7.5 Xichang earthquake using the empirical Green’s function method. The uncertainties of the parameters, such as the number, area, and locations of asperities, are considered. The synthetic time histories, peak ground accelerations (PGAs), and response spectra are obtained through simulation. The main results are as follows. (1) The synthetic Xichang earthquake (such as the ground-motion intensity and attenuation characteristic of the PGA) matches well with the M 8.0 Wenchuan earthquake and M 7.3 Jiji earthquake. When the number of asperities is 1 or 2, the PGA characteristics of the Xichang earthquake match well not only with the Next Generation Attenuation-West2 (2014) ground-motion model in the range of 100 km but also with the seismic ground-motion parameter zonation map of China in the range of 20–100 km. (2) The prediction results based on the asperity source model are relatively reliable in the range of 20–100 km. The one-asperity and two-asperity models of the Xichang earthquake match better than the three-asperity and four-asperity models. (3) We can speculate that when the M 7.5 earthquake struck the Xichang area, the damage was relatively strong. The PGA may have exceeded 1.0g in the meizoseismal area, and the seismic intensity in the meizoseismal area may have reached or exceeded a degree of X–XI. Therefore, the synthesized M 7.5 Xichang earthquake has the strength characteristics of a large destructive earthquake.

Simulation of Strong Ground Motion in the National Capital Region, India, from a Future 8.5 Magnitude Earthquake Using Two-Step Empirical Green’s Function Method

2021 ◽  
Author(s):  
Krishnavajjhala Sivaram
Keyword(s):  
Green’S Function ◽  
Ground Motion ◽  
Green's Function ◽  
Seismic Gap ◽  
National Capital Region ◽  
Empirical Green’S Function ◽  
Ground Acceleration ◽  
Capital Region ◽  
National Capital ◽  
Empirical Green's Function

ABSTRACT In this study, I simulate high-frequency ground motions at five stations in the National Capital Region (NCR) of India for a large hypothetical Mw 8.5 earthquake in the Himalayan central seismic gap, at fault-distances of about 200–300 km. A smaller magnitude earthquake (22 July 2007 Mw 4.9 Kharsali) is used as the first-step empirical Green’s function (EGF) for the synthesis of an intermediate-sized earthquake of magnitude Mw 6.8 (1991 Uttarkashi earthquake). In the second step, the records of Mw 6.8 synthetics are further used as the EGF in the simulation of the postulated Mw 8.5 earthquake. Because the target region for the postulated earthquake is devoid of the necessary information on the geophysical constraints, I perform a suite of simulations for plausible scenarios of fault dimensions, stress-drop ratios, C, and scaling factor, N (between the EGF and target earthquake). This article uses heterogeneous slip distributions and variable stress drops on the rupture plane to simulate the target earthquake, based on the power spectral density of the von Karman correlation function. The estimated values of the ground-motion intensity measure (GMIM) such as peak ground acceleration, along with the engineering parameters such as the 5% damped, pseudospectral acceleration (Sa), Arias intensity (IA), and significant duration (TD), are compared for both the recorded and the simulated time histories. The estimated GMIMs of the Mw 6.8 synthetics are examined with those of the 1991 Mw 6.8 Uttarkashi earthquake, whereas the Mw 8.5 simulations are compared with those predicted by prevalent ground-motion prediction equations for rock sites. The Mw 8.5 earthquake scenarios indicate higher GMIMs and seismic hazard in the NCR, principally due to the area being underlain by sediment layers and fluvial deposits.

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