1969 Sulawesi earthquake
   | |
| UTC time | 1969-02-23 00:36:58 |
|---|---|
| ISC event | 812497 |
| USGS-ANSS | ComCat |
| Local date | February 23, 1969 |
| Local time | 08:56[1] |
| Magnitude | 7.0 Mw |
| Depth | 15.0 km (9 mi) |
| Epicenter | 3°12′04″S 118°54′14″E / 3.201°S 118.904°E |
| Fault | Majene Thrust |
| Type | Thrust |
| Max. intensity | MMI VIII (Severe)[1] |
| Tsunami | yes |
| Casualties | 664 |
The western coast of West Sulawesi was struck by a major earthquake on 23 February 1969 at 00:36 UTC. It had a magnitude of 7.0 Mw and a maximum felt intensity of VIII on the Modified Mercalli intensity scale.[2][1] It triggered a major tsunami that caused significant damage along the coast of the Makassar Strait. At least 64 people were killed, with possibly a further 600 deaths caused by the tsunami.[1]
Tectonic setting
Earthquake
The earthquake had an estimated magnitude of 7.4 Ms,[1] later recalculated to be 7.0 Mw .[2] It was caused by movement on the Majene Thrust, which was also responsible for the 2021 West Sulawesi earthquake 52 years later.[7] Modelling of the earthquake by Pranantyo and others suggested rupture occurred across a rectangular fault plane measuring 40 km by 20 km. A maximum coseismic slip of 1.5 meters was estimated. The maximum Modified Mercalli intensity was VIII (Severe), causing serious damage at the coast.[8]
Tsunami
The earthquake triggered a significant tsunami, with a maximum run-up of 4 meters at Peletoang and 1.5 meters at both Parosanga and Palipi.[9] The same modelling by Pranantyo and others could not replicate the 4-meter tsunami run-up along Peletoang. Simulations of various scenarios for the earthquake and tsunami only generated a maximum tsunai height of 2.25 meters. It is possible that a submarine landslide triggered the large tsunami.[8]
Damage
The city of Majene was particularly badly affected, with the foundations of four out of five of tile brick buildings suffering serious effects. Wooden buildings escaped with only minor effects, but unreinforced masonry walls were badly damaged. A number of bridges were damaged beyond repair.[1]
The tsunami caused local flooding, damaging banana plantations along the coast. Many wooden buildings were washed away by the waves. At Majene's harbour, the pier was seriously affected due to the effects of subsidence. Witnesses mention a "roaring sound" just before the tsunami.[9]
At least 64 deaths were reported, with one news story also mentioning another 600 deaths due to the tsunami. A further 97 injuries were also reported.[1]
See also
References
- ^ doi:10.7289/V5TD9V7K. Retrieved 16 January 2020.)
{{cite journal}}: Cite journal requires|journal=(help - ^ a b ANSS. "Sulawesi 1969 : M 7.0 - Sulawesi, Indonesia". Comprehensive Catalog. U.S. Geological Survey. Retrieved 16 January 2020.
- ^ .
- ^ ANSS. "Sulawesi 2018: M 7.5 - 70km N of Palu, Indonesia". Comprehensive Catalog. U.S. Geological Survey. Retrieved 28 September 2018.
- .
- S2CID 140682113.
- ^ "BMKG : Gempa Majene Merusak" (in Indonesian). Media Indonesia. Retrieved 15 January 2021.
- ^ S2CID 240430042.
- ^ doi:10.7289/V5TD9V7K. Retrieved 16 January 2020.)
{{cite journal}}: Cite journal requires|journal=(help