Empirical Attenuation relationship for Peak Ground Horizontal Acceleration for North-East Himalaya

Abstract

North-East India is located in one of the most seismic prone areas of the world. India has faced several devastating earthquakes in the past. The largest of these have originated in the Himalayan plate boundary region, which has remained a region of great scientific and engineering interest. In spite of this, very little seismological information is available about North-East India, which is the focus for present study. Only few attenuation relationships are available for this region, which are most valuable in a region where too much strong motion recordings are not available. However in recent time, with the inception of 300 strong motion instruments under Indian National Strong Motion Network deployed under Mission Mode project (Government of India), a good quality of strong motion data became available. Taking the advantage of data collected by this network and earlier analogue strong motion arrays, an endeavor has been made to develop an empirical attenuation relationship for peak horizontal ground accelerations for North-East Himalayan region in India. The data set consists of 216 peak ground horizontal accelerations from 24 earthquakes (4.0≤M≤6.8) recorded by strong-motion arrays and National Strong Motion Network project in India. The present analysis uses a two-step stratified regression model. The estimated attenuation relationship for the region is log 1.497 0.3882 1.19 . )Where A is the peak ground acceleration (g), M is the magnitude, and X is the hypocentral distance from the source. The residual sum of squares is 0.1451. The obtained Empirical attenuation relationship will provide better insight for site specific studies as well as for hazard estimation for North-East Himalayan region. Attenuation relationships for expected peak ground acceleration (g) have been presented for magnitudes 5, 6, 7 and 8 for North-East Himalayan region.

Attenuation Relationships for the Horizontal Component of Peak Ground Acceleration (PGAH) Using Gene Expression Programing (GEP) and Group Method of Data Handling (GMDH)

“…Every year, new earthquakes occur, accelerometers are installed in new areas and the accelerometer network expands, and in general, the earthquake catalog becomes more complete and accurate. On the other hand, providing new methods for Present study (GMDH) Sarma and Frey [15] Ornthammarath et al [18] Alavi and Gandomi [21] Kumar et al [25] Javan et al [26] Abdelfattah et al [30] 3.5 Present study (GMDH) Sarma and Frey [15] Ornthammarath et al [18] Alavi and Gandomi [21] Kumar et al [25] Javan et al [26] Abdelfattah et al [30] 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 M FIGURE 16: PGAH curve in terms of magnitude for a hypocentral distance of 100 km and shear wave velocities of 400 m/s. 12 Civil Engineering regression has caused that new attenuation relationships are always needed in earthquake risk analysis.…”

“…One of the most recent attenuation relations was offered by Kumar et al [25]. The relationship that was determined for the northeastern Himalaya region is presented as Equation ( 5):…”

Empirical Green’s Function Simulations Toward Site-Specific Ground Motion Prediction for Kopili Fault of NER India

“…While results from Sharma et al (2009) is used which combine data from the Indian Himalayas and the Zagros (Iran), since Zagros has been reported as having comparable seismotectonic characteristics to the Himalayas (McCaffrey and Nobelek, 1998;Talebian and Jackson, 2004). Region specific GMPE were also included for comparison, as such, Kumar et al (2017) and Ramakrishnan et al ( 2022) recently developed a new GMPE from real earthquake events entirely for north east India. While, Bahuguna and Sil (2020) developed GMPE particularly for Assam state which is also included.…”

“…the following up-to-date GMPEs:Ambraseys et al (2005),Akkar and Bommer (2007),Sharma et al (2009),Anbazhagan et al (2013),Kumar et al (2017), Ramakrishnan et al…”

Deterministic seismic hazard analysis of north and central Himalayas using region-specific ground motion prediction equations

“…The use of GMPEs developed using synthetic data or GMPEs developed for other regions in SHA for a complex tectonic environment like that of the Himalayas had been recognized undependable in numerous recent studies (Anbazhagan et al 2013;Ramkrishnan et al 2018;Ramkrishnan et al 2019aRamkrishnan et al , b, 2020. Furthermore, the region-speciBc GMPEs available for the NCH had critical magnitude and distance limitations as well (Anbazhagan et al 2013;Kumar et al 2017;Ramkrishnan et al 2020). This calls for running an SHA for the region using a reliable region-speciBc GMPE, which is developed using actual recorded ground-motion data.…”