Delineating site response from microtremors: A case study

TL;DR

This study estimates the fundamental site response frequencies using receiver function techniques on microtremor data across different lithologies, revealing heterogeneity in the subsurface structure.

Contribution

It applies the receiver function method to microtremor data for site response estimation, confirming frequency variations across different geological settings.

Findings

Resonance frequencies range from 3 to 7 Hz.

Frequency variation indicates subsurface heterogeneity.

Results align with previous ambient noise studies.

Abstract

We report estimation of site response in the form of fundamental frequency. Towards this objective, we deploy widely established receiver function technique. Taking locally recorded events as inputs, we implement this technique to estimate resonance frequency in three receiver sites, characterized by varying lithology underneath. It is observed that resonance frequencies varies from 3 to 7 Hz, which is also confirmed by our previous studies of estimates from ambient noise recordings with reference to identical sites. Variation of frequency implies existence of heterogeneity in the study area.