The 2017 ML 5.4 Pohang earthquake sequence, Korea, recorded by a dense seismic network

Kwang Hee Kim; Wooseok Seo; Jongwon Han; Joa Kwon; Su Young Kang; Jin Han Ree; Sungshil Kim; Kang Liu

doi:10.1016/j.tecto.2019.228306

The 2017 M_L 5.4 Pohang earthquake sequence, Korea, recorded by a dense seismic network

Kwang Hee Kim, Wooseok Seo, Jongwon Han, Joa Kwon, Su Young Kang, Jin Han Ree, Sungshil Kim, Kang Liu

Department of Earth and Environmental Sciences

Research output: Contribution to journal › Article › peer-review

24 Citations (Scopus)

Abstract

The 2017 M_L 5.4 Pohang Earthquake in southeastern Korea, which was induced by fluid injection from an enhanced geothermal system, and its foreshock–aftershock sequence has been recorded by a dense and portable temporary seismic array. The hypocentral distribution of the earthquake sequence reveals the reactivation of a complex subsurface fault system that was previously unmapped. Aftershock seismicity propagated to the southwest and revealed previously unknown fault segments. The aftershocks tend to concentrate along the tips of the main rupture, with a lack of aftershocks around the mainshock hypocenter. This pattern suggests that the stress in the mainshock area was almost completely released during the mainshock and early aftershock phase, and that the recurrence of moderate to large earthquakes in the hypocentral area is unlikely compared with the marginal areas. A new rupture occurred along the southwestern margin of the main rupture after the largest aftershock (M_L 4.6).

Original language	English
Article number	228306
Journal	Tectonophysics
Volume	774
DOIs	https://doi.org/10.1016/j.tecto.2019.228306
Publication status	Published - 2020 Jan 5

Keywords

2017 Pohang Earthquake
Aftershock
Fault
Induced seismicity
Seismic hazard

ASJC Scopus subject areas

Geophysics
Earth-Surface Processes

Access to Document

10.1016/j.tecto.2019.228306

Cite this

@article{36343528d61e4336a02877d733392699,

title = "The 2017 ML 5.4 Pohang earthquake sequence, Korea, recorded by a dense seismic network",

abstract = "The 2017 ML 5.4 Pohang Earthquake in southeastern Korea, which was induced by fluid injection from an enhanced geothermal system, and its foreshock–aftershock sequence has been recorded by a dense and portable temporary seismic array. The hypocentral distribution of the earthquake sequence reveals the reactivation of a complex subsurface fault system that was previously unmapped. Aftershock seismicity propagated to the southwest and revealed previously unknown fault segments. The aftershocks tend to concentrate along the tips of the main rupture, with a lack of aftershocks around the mainshock hypocenter. This pattern suggests that the stress in the mainshock area was almost completely released during the mainshock and early aftershock phase, and that the recurrence of moderate to large earthquakes in the hypocentral area is unlikely compared with the marginal areas. A new rupture occurred along the southwestern margin of the main rupture after the largest aftershock (ML 4.6).",

keywords = "2017 Pohang Earthquake, Aftershock, Fault, Induced seismicity, Seismic hazard",

author = "Kim, {Kwang Hee} and Wooseok Seo and Jongwon Han and Joa Kwon and Kang, {Su Young} and Ree, {Jin Han} and Sungshil Kim and Kang Liu",

note = "Funding Information: The authors thank KMA (earthquake catalog and waveforms) and KIGAM (waveforms) for providing the seismic data. Figs. 1a and 2b were created using Generic Mapping Tools (Wessel et al. 2013). This study was supported by the KMA Research Development Program (Grant KMI2018-02810). Funding Information: The authors thank KMA (earthquake catalog and waveforms) and KIGAM (waveforms) for providing the seismic data. Figs. 1 a and 2 b were created using Generic Mapping Tools ( Wessel et al., 2013 ). This study was supported by the KMA Research Development Program (Grant KMI2018-02810 ). Publisher Copyright: {\textcopyright} 2019 Elsevier B.V.",

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AU - Kang, Su Young

AU - Ree, Jin Han

AU - Kim, Sungshil

AU - Liu, Kang

N1 - Funding Information: The authors thank KMA (earthquake catalog and waveforms) and KIGAM (waveforms) for providing the seismic data. Figs. 1a and 2b were created using Generic Mapping Tools (Wessel et al. 2013). This study was supported by the KMA Research Development Program (Grant KMI2018-02810). Funding Information: The authors thank KMA (earthquake catalog and waveforms) and KIGAM (waveforms) for providing the seismic data. Figs. 1 a and 2 b were created using Generic Mapping Tools ( Wessel et al., 2013 ). This study was supported by the KMA Research Development Program (Grant KMI2018-02810 ). Publisher Copyright: © 2019 Elsevier B.V.

PY - 2020/1/5

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