1996 Sulawesi earthquake

Earthquake in Indonesia 1996 Sulawesi earthquake 24.0 km 9 dead, 63 injured 2–4 m ft XM 7.9 – Minahasa, Sulawesi, Indonesia https://earthquake.usgs.gov/earthquakes/eventpage/usp00079zv/executive USGS-ANSS 24 March 2021 $1.2M USD Sulawesi, Indonesia Thrust North Sulawesi Trench 7.9 w yes ~30 seconds 16:05 CIT January 1, 1996 usp00079zv 939295 1996-01-01 08:05:10 Indonesia_Sulawesi#Indonesia -0.729 119.931 inline, title On January 1, 1996, at 4:05 p.m. Central Indonesia Time, an earthquake with an epicenter in the Makassar Strait struck north of Minahasa on the island of Sulawesi, Indonesia. The earthquake measured 7.9 on the moment magnitude scale and was centered off Tolitoli Regency in Central Sulawesi, or 25 km from the Tonggolobibi village. A tsunami of 2–4 m ft was triggered by this earthquake as a result.Tsunami Event Information https://www.ngdc.noaa.gov/hazel/view/hazards/tsunami/event-more-info/2259 27 November 2020 National Centers for Environmental Information At least 350 buildings were badly damaged, nine people died and 63 people were injured.Significant Earthquake Information https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/5428 27 November 2020 National Centers for Environmental Information Tectonic setting The North Sulawesi Trench is a subduction zone parallel to the Minahasa Peninsula where the Sunda plate dives beneath the Molucca Sea plate at a rate of 4 cm/yr. Here, three major tectonic plates, the Sunda, Australian and Philippine Sea plates interact in a complex manner, broken up into several smaller microplates.Hamilton Warren 1973 Tectonics of the Indonesian Region https://gsm.org.my/products/702001-101358-PDF.pdf Geology Society Malaysia 6 2022-11-26 2020-11-27 https://web.archive.org/web/20221126130700/https://gsm.org.my/products/702001-101358-PDF.pdf dead The North Sulawesi Subduction Zone joins the Palu-Koro Fault at its westernmost tip. Earthquake The thrust fault which this earthquake occurred along had a very shallow dip angle of 7°, during the event, a 90 × 60 km section of it had ruptured. An average slip was estimated at 1.8 meters. The earthquake took place along a relay zone between the North Sulawesi Trench and Palu-Koro Fault. The strike-slip component of this oblique-thrust event was a result of interaction with the Palu-Koro Fault. The rupture process took roughly 30 seconds.J. M. Gómez R. Madariaga A. Walpersdorf E. Chalard The 1996 Earthquakes in Sulawesi, Indonesia https://www.researchgate.net/publication/287000015 Bulletin of the Seismological Society of America 2000 90 3 739–751 10.1785/0119990055 2000BuSSA..90..739G On Pangalasean Island, uplift of 0.3–0.5 m ft was determined. Two aftershocks in July, a magnitude 6.6 and 7.0 on the 16th and 22nd struck about 50 km northeast of the January mainshock. This event was larger but far less deadly compared to the w 7.5 Sulawesi earthquake in 2018 to the south. The mainshock resulted in a large coulomb stress transfer component around the Palu-Koro Fault. Many additional aftershocks were triggered along the Palu-Koro Fault following the mainshock.Vigny Christophe Perfettini Hugo Walpersdorf Andrea Lemoine Anne Simons Wim van Loon Danny Ambrosius Boudewijn Stevens Colleen McCaffrey Rob Morgan Peter Bock Yehuda Subarya Cecep Manurung Parluhutan Kahar Joenil Abidin Hasanuddin Z. Abu Samad H. Migration of seismicity and earthquake interactions monitored by GPS in SE Asia triple junction: Sulawesi, Indonesia Journal of Geophysical Research: Solid Earth 2002 107 B10 2231 10.1029/2001JB000377 2002JGRB..107.2231V There was also an increased rate in seismicity around the island after the 1996 shock.Lei Dongning Wu Jianchao Yang Gang Coseismic Coulomb stress changes imparted by the 1996 Minahasa Mw 7.9 earthquake on the 2018 Palu Mw 7.5 earthquake and expected seismicity rate changes Terra Nova 2019 32 1 44–52 10.1111/ter.12434 210288256 A number of magnitude 6.0+ earthquakes occurred along the fault and was triggered after the 1996 thrust mainshock. In May and October 1998, two earthquakes measuring 6.6 and 6.0 w, respectively, occurred near the Palu–Koro Fault. The former event was the result of strike-slip faulting while the latter displayed thrusting on a shallow, southeast dipping fault. Stress transfer later brought the Palu-Koro Fault closer to rupture and eventually failed, causing the 2018 earthquake. Tsunami The tsunami inundated more than 100 km of coastline along with Northern Sulawesi between 5–10 minutes after the tremor.Efim Pelinovsky Dede Yuliadi Gegar Prasetya Rahman Hidayat 1997 The 1996 Sulawesi Tsunami https://link.springer.com/article/10.1023/A:1007904610680 Natural Hazards 16 29–38 10.1023/A:1007904610680 129481734 subscription The run-up heights of these waves were between 1.6–3.4 m ft, according to eyewitness. More than 400 houses in the village of Tonggolobibi were destroyed when the waves swept through. The water destroyed 183 houses and damaged 228 units around the Bangkir-Tolitoli area. About 100 km mi of coastline was affected, there were no reports of the tsunami recorded outside of Sulawesi, thus inferring that the tsunami was localized. The tsunami penetrated 200 m ft up riverbeds and carried five boats, including two 500-ton motorboats 250 meters onshore. Since the tsunami occurred during a high tide of 0.59 m ft, and there was subsidence of the land of about 0.7 m ft, estimating the height of the tsunami was challenging. See also List of earthquakes in 1996 List of earthquakes in Indonesia 1968 Sulawesi earthquake 1969 Sulawesi earthquake 2021 West Sulawesi earthquake References Category:1996 earthquakes Category:Earthquakes in Indonesia Category:Tsunamis in Indonesia Category:1990s floods in Asia Category:1996 floods Category:January 1996 in Indonesia Category:20th century in Sulawesi Category:1996 disasters in Indonesia Sulawesi