Three-Dimensional Pore Fluid Pressures in Source Region of 2017 Pohang Earthquake Inferred From Earthquake Focal Mechanisms

Toshiko Terakawa, Wooseok Seo, Kwang Hee Kim, Jin Han Ree

Research output: Contribution to journalArticlepeer-review

Abstract

We analyzed 91 focal mechanism data with relocated hypocenters to estimate the 3-D pore fluid pressure field in the source region of the 2017 Pohang earthquake in South Korea using the method of focal mechanism tomography. The upper limit of pore fluid pressure was 8 ± 3 MPa in a location northwest of the enhanced geothermal system. The overpressurized fluids were localized in the footwall of the causative fault. It was directly connected to the open hole section of PX2, and fluid injection into this hole could have triggered the mainshock.

Original languageEnglish
Article numbere2019GL085964
JournalGeophysical Research Letters
Volume47
Issue number9
DOIs
Publication statusPublished - 2020 May 16

Keywords

  • Pohang earthquake
  • earthquake focal mechanism
  • friction coefficient
  • inversion analysis
  • pore fluid pressure
  • stress

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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