1976 Moro Gulf earthquake
Lebak, Mindanao | |
UTC time | 1976-08-16 16:11:08 |
---|---|
ISC event | 709878 |
USGS-ANSS | ComCat |
Local date | August 17, 1976 |
Local time | 00:11:07 |
Magnitude | 8.0 Mw |
Depth | 20 km (12 mi) |
Epicenter | 6°17′N 124°05′E / 6.29°N 124.09°E[1] |
Type | Megathrust |
Areas affected | Philippines |
Max. intensity | |
Tsunami | 4–5 m (13–16 ft) |
Casualties | 5,000–8,000 dead
10,000 injured 90,000 homeless |
The 1976 Moro Gulf earthquake and tsunami occurred on August 17, 1976, at 00:11 local time near the islands of
Tectonic summary
Several fault zones in the region are capable of producing major earthquakes and destructive local tsunamis. The two major fault zones that are most dangerous are the
Earthquake
The earthquake occurred in an region where typical seismicity originates at 500 km (310 mi) depth on the Wadati–Benioff zones associated with subduction along the Sangihe and Mindanao islands. The Philippines is characterised by several complex and active subduction zones. The most geologically dominant in the region is the Philippine Trench located east of Mindanao. It dips to the west as represented by the Wadati–Benioff zone which can be detected to at least 200 km (120 mi).[3][4]
The mainshock had a shallow focal depth and represented
Impact
The initial earthquake was widespread and was felt as far as the central Philippine islands of the
The maximum height of the waves reached 9 meters at Lebak on the isla; 4.3 meters at Alicia; 3 meters at Resa Bay on the eastern coast of Basilan; and at the islands of Jolo and Sacol.[5] At least 5,000 people died during the earthquake and tsunami, with thousands more remaining missing.[6] Some reports say that as many as 8,000 people lost their lives in total, with ninety percent of all deaths the result of the following tsunami.
Initially over 8,000 people were officially counted as killed or missing, 10,000 injured, and 90,000 homeless, making it one of the most devastating disasters in the history of the
In Zamboanga City, 14 buildings were partially damaged. The city was spared from serious damage of the tsunami triggered by this earthquake because the
Intensity
scales |
Location |
---|---|
VII | Cotabato City; Jolo-Sulu; Zamboanga City |
VI | Basilan City; Pagadian City; Dipolog City; Malaybalay-Bukidnon |
V | Cagayan de Oro City; Davao City; General Santos |
IV | Dumaguete; Hinatuan Surigao del Sur; Tagbilaran-Bohol; Cebu City; Surigao-Surigao del Norte |
II | Roxas City; Iloilo City; Tacloban City; Legaspi City; Palo-Leyte; Catbalogan-Samar |
See also
References
- ISBN 978-0124406520.
- ^ ISC (2022), ISC-GEM Global Instrumental Earthquake Catalogue (1904–2018), Version 9.1, International Seismological Centre
- ^ .
- ^ .
- ISBN 978-0-9962579-0-9. Retrieved August 22, 2017.
- ^ History of Tsunami Devastation
- ^ ISBN 978-0-7881393-1-4.
- ^ "Moro Gulf Earthquake – 17 August 1976". Philippine Institute of Volcanology and Seismology. Archived from the original on October 15, 2013. Retrieved October 15, 2013.
- ^ Philippine Institute of Volcanology and Seismology (2018). "PHIVOLCS Earthquake Intensity Scale (PEIS)". Retrieved November 13, 2019.
External links
- Philippines Institute of Volcanology and Seismology Archived January 29, 2010, at the Wayback Machine
- The Earthquake and Tsunami of August 16, 1976, in the Philippines – The Moro Gulf Tsunami" – George Pararas-Carayannis
- The International Seismological Centre has a bibliography and/or authoritative data for this event.