The 2016 Mw 6.5 Pidie Jaya, Aceh, North Sumatra, Earthquake : reactivation of an unidentified sinistral fault in a region of distributed deformation
On 6 December 2016, an Mw 6.5 earthquake occurred in Pidie Jaya, Aceh, about 30 km to the north of the Sumatran fault (SF) that killed more than 100 people and destroyed ∼3000 buildings. Mainshock focal mechanism inversions using regional Agency for Meteorology, Climatology, and Geophysics of Indone...
| Main Authors: | , , , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
| Published: |
2019
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| Online Access: | https://hdl.handle.net/10356/104479 http://hdl.handle.net/10220/49994 |
| _version_ | 1826118303206080512 |
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| author | Muzli, Muzli Umar, Muksin Nugraha, Andri Dian Bradley, Kyle Edward Widiyantoro, Sri Erbas, Kemal Jousset, Philippe Rohadi, Supriyanto Nurdin, Irwandi Wei, Shengji |
| author2 | Asian School of the Environment |
| author_facet | Asian School of the Environment Muzli, Muzli Umar, Muksin Nugraha, Andri Dian Bradley, Kyle Edward Widiyantoro, Sri Erbas, Kemal Jousset, Philippe Rohadi, Supriyanto Nurdin, Irwandi Wei, Shengji |
| author_sort | Muzli, Muzli |
| collection | NTU |
| description | On 6 December 2016, an Mw 6.5 earthquake occurred in Pidie Jaya, Aceh, about 30 km to the north of the Sumatran fault (SF) that killed more than 100 people and destroyed ∼3000 buildings. Mainshock focal mechanism inversions using regional Agency for Meteorology, Climatology, and Geophysics of Indonesia (BMKG) broadband data and teleseismic waveform data all indicate a strike-slip event with a centroid depth of 11-15 km. The observed macrointensity data show that most of the damaged buildings are distributed along the coast, approximately perpendicular to the ruptured fault strike instead of parallel with it. The strong shaking and damage sites are primarily located on the coastal sedimentary soils, highlighting the importance of site conditions in determining risk. We used one-month data recorded by nine temporal broadband stations to locate aftershocks with gridsearch and double-difference algorithms, thereby resolving a linear trend of seismicity aligned in a northeast-southwest direction. The refined aftershock locations indicate a leftlateral rupture that is in agreement with the preliminary finite-fault slip inversion as well as geomorphic signatures of local geological structure. Using a well-located ML 4.2 aftershock for path calibration, we relocated the mainshock epicenter with regional P-wave arrivals. The refined epicenter falls within the cloud of the well-located aftershocks, whereas locations from the global and regional catalogs are located 10-20 km away. Aftershock focal mechanisms determined by the first motion reveal similar solutions as the mainshock. This earthquake sequence ruptured a previously unidentified fault that is either located at the west of the fault that produced the 1967 Mw 6.1 earthquake sequence or is actually at the same fault. The Pidie Jaya earthquake and other off-SF events suggest strong distributed crustal deformation in Aceh, highlighting the need for better understanding of active faulting and seismic hazard in this region. |
| first_indexed | 2024-10-01T04:41:30Z |
| format | Journal Article |
| id | ntu-10356/104479 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T04:41:30Z |
| publishDate | 2019 |
| record_format | dspace |
| spelling | ntu-10356/1044792020-09-26T21:29:19Z The 2016 Mw 6.5 Pidie Jaya, Aceh, North Sumatra, Earthquake : reactivation of an unidentified sinistral fault in a region of distributed deformation Muzli, Muzli Umar, Muksin Nugraha, Andri Dian Bradley, Kyle Edward Widiyantoro, Sri Erbas, Kemal Jousset, Philippe Rohadi, Supriyanto Nurdin, Irwandi Wei, Shengji Asian School of the Environment Earth Observatory of Singapore Earthquake Pidie Jaya, Aceh, Sumatra Science::Geology::Volcanoes and earthquakes On 6 December 2016, an Mw 6.5 earthquake occurred in Pidie Jaya, Aceh, about 30 km to the north of the Sumatran fault (SF) that killed more than 100 people and destroyed ∼3000 buildings. Mainshock focal mechanism inversions using regional Agency for Meteorology, Climatology, and Geophysics of Indonesia (BMKG) broadband data and teleseismic waveform data all indicate a strike-slip event with a centroid depth of 11-15 km. The observed macrointensity data show that most of the damaged buildings are distributed along the coast, approximately perpendicular to the ruptured fault strike instead of parallel with it. The strong shaking and damage sites are primarily located on the coastal sedimentary soils, highlighting the importance of site conditions in determining risk. We used one-month data recorded by nine temporal broadband stations to locate aftershocks with gridsearch and double-difference algorithms, thereby resolving a linear trend of seismicity aligned in a northeast-southwest direction. The refined aftershock locations indicate a leftlateral rupture that is in agreement with the preliminary finite-fault slip inversion as well as geomorphic signatures of local geological structure. Using a well-located ML 4.2 aftershock for path calibration, we relocated the mainshock epicenter with regional P-wave arrivals. The refined epicenter falls within the cloud of the well-located aftershocks, whereas locations from the global and regional catalogs are located 10-20 km away. Aftershock focal mechanisms determined by the first motion reveal similar solutions as the mainshock. This earthquake sequence ruptured a previously unidentified fault that is either located at the west of the fault that produced the 1967 Mw 6.1 earthquake sequence or is actually at the same fault. The Pidie Jaya earthquake and other off-SF events suggest strong distributed crustal deformation in Aceh, highlighting the need for better understanding of active faulting and seismic hazard in this region. Accepted version 2019-09-25T01:26:25Z 2019-12-06T21:33:42Z 2019-09-25T01:26:25Z 2019-12-06T21:33:42Z 2018 Journal Article Muzli, M., Umar, M., Nugraha, A. D., Bradley, K. E., Widiyantoro, S., Erbas, K., … Wei, S. (2018). The 2016 Mw 6.5 Pidie Jaya, Aceh, North Sumatra, Earthquake : reactivation of an unidentified sinistral fault in a region of distributed deformation. Seismological Research Letters, 89(5), 1761-1772. doi:10.1785/0220180068 0895-0695 https://hdl.handle.net/10356/104479 http://hdl.handle.net/10220/49994 10.1785/0220180068 en Seismological Research Letters © 2018 Seismological Society of America (SSA). All rights reserved. This paper was published in Seismological Research Letters and is made available with permission of Seismological Society of America (SSA). 60 p. application/pdf |
| spellingShingle | Earthquake Pidie Jaya, Aceh, Sumatra Science::Geology::Volcanoes and earthquakes Muzli, Muzli Umar, Muksin Nugraha, Andri Dian Bradley, Kyle Edward Widiyantoro, Sri Erbas, Kemal Jousset, Philippe Rohadi, Supriyanto Nurdin, Irwandi Wei, Shengji The 2016 Mw 6.5 Pidie Jaya, Aceh, North Sumatra, Earthquake : reactivation of an unidentified sinistral fault in a region of distributed deformation |
| title | The 2016 Mw 6.5 Pidie Jaya, Aceh, North Sumatra, Earthquake : reactivation of an unidentified sinistral fault in a region of distributed deformation |
| title_full | The 2016 Mw 6.5 Pidie Jaya, Aceh, North Sumatra, Earthquake : reactivation of an unidentified sinistral fault in a region of distributed deformation |
| title_fullStr | The 2016 Mw 6.5 Pidie Jaya, Aceh, North Sumatra, Earthquake : reactivation of an unidentified sinistral fault in a region of distributed deformation |
| title_full_unstemmed | The 2016 Mw 6.5 Pidie Jaya, Aceh, North Sumatra, Earthquake : reactivation of an unidentified sinistral fault in a region of distributed deformation |
| title_short | The 2016 Mw 6.5 Pidie Jaya, Aceh, North Sumatra, Earthquake : reactivation of an unidentified sinistral fault in a region of distributed deformation |
| title_sort | 2016 mw 6 5 pidie jaya aceh north sumatra earthquake reactivation of an unidentified sinistral fault in a region of distributed deformation |
| topic | Earthquake Pidie Jaya, Aceh, Sumatra Science::Geology::Volcanoes and earthquakes |
| url | https://hdl.handle.net/10356/104479 http://hdl.handle.net/10220/49994 |
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