MINDANAO, PHILIPPINES earthquakes - December 2, 2023

[JJackson]

There have been a number of earthquakes off the coast (largest to date 7.6) and a tsunami warning, now rescinded There may however be further quakes, so the situation is not necessarily over.
https://earthquake.usgs.gov/earthqu...3601,493.5553&listOnlyShown=true&timeZone=utc
https://www.tsunami.gov/events/PHEB/2023/12/02/23336002/3/WEPA40/WEPA40.txt

 

[sharon sanders]

Tectonic Summary


The December 2, 2023, M 7.6 earthquake off the southeast coast of the island of Mindanao, Philippines occurred as a result of oblique reverse faulting at shallow depth ~75 km west of the Philippine Trench. Focal mechanism solutions indicate that rupture occurred as a result of shallow reverse faulting consistent with subduction interface fault. At the location of the earthquake, the Philippine Sea plate moves west-northwest at a velocity of about 103 mm/yr with respect to the Sunda plate. While commonly plotted as points on maps, earthquakes the size of the December 2, 2023, event are more appropriately described as slip over a larger fault area. Earthquakes of this size are typically about 100x35 km (length x width).

As at many subduction zone plate boundaries, the Philippines frequently experiences moderate to large earthquakes. 127 additional earthquakes of M6 or larger have occurred over the past 100 years within 250 km of the December 2, 2023, earthquake. 15 of these were M 7 or larger. Earthquakes in the Philippines region exhibit diverse styles of faulting that are indicative of the locally complex tectonic motions. Moreover, this region experiences earthquakes across a range of depths, from shallow surface rupturing strike-slip earthquakes, to deep earthquakes located within subducting oceanic slabs.
​
https://earthquake.usgs.gov/earthquakes/eventpage/us7000lff4/executive