3-D seismic structure of the source area of the 1993 Latur, India, earthquake and its implications for rupture nucleations

Sagarfes Mukhopadhyay, O. P. Mishra, D. Zhao, J. R. Kayal

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)

Abstract

The Latur earthquake (Mw 6.1) of 29 September 1993 is a rare stable continental region (SCR) earthquake that occurred on a previously unknown blind fault. In this study, we determined detailed three-dimensional (3-D) P- and S-wave velocity (Vp, Vs) and Poisson's ratio (σ) structures by inverting the first P- and S-wave high-quality arrival time data from 142 aftershocks that were recorded by a network of temporary seismic stations. The source zone of the Latur earthquake shows strong lateral heterogeneities in Vp, Vs and σ structures, extending in a volume of about 90 × 90 ×15 km3. The mainshock occurred within, but near the boundary, of a low-Vp, high-Vs and low-σ zone. This suggests that the structural asperities at the mainshock hypocenter are associated with a partially fluid-saturated fractured rock in a previously unknown source zone with intersecting fault surfaces. This might have triggered the 1993 Latur mainshock and its aftershock sequence. Our results are in good agreement with other geophysical studies that suggest high conductivity and high concentration of radiogenic helium gas beneath the source zone of the Latur earthquake. Our study provides an additional evidence for the presence of fluid related anomaly at the hidden source zone of the Latur earthquake in the SCR and helps us understand the genesis of damaging earthquakes in the SCR of the world.

Original languageEnglish
Pages (from-to)1-16
Number of pages16
JournalTectonophysics
Volume415
Issue number1-4
DOIs
Publication statusPublished - 2006 Mar 27
Externally publishedYes

Keywords

  • 3-D tomography
  • Latur earthquake
  • Poisson's ratio
  • Saturation rate
  • Stable continental region

ASJC Scopus subject areas

  • Geophysics
  • Earth-Surface Processes

Fingerprint Dive into the research topics of '3-D seismic structure of the source area of the 1993 Latur, India, earthquake and its implications for rupture nucleations'. Together they form a unique fingerprint.

Cite this