Sciency Thoughts: Magnitude 7.0 Earthquake hits northern Luzon Island, the Philippines, killing at least five.

Saturday 30 July 2022

Magnitude 7.0 Earthquake hits northern Luzon Island, the Philippines, killing at least five.

The Philippine Institute of Volcanology and Seismology recorded a Magnitude 7.0 Earthquake at a depth of 10 km about 13 km to the southwest of the town of Dolores in Eastern Samar Province on northern Luzon Island, Philippines, slightly before 8.45 am local time (slightly before 0.45 am GMT) on Wednesday 27 July 2022. Five people are known to have died as a result of this event, with about thirty more injured, with the Earthquake causing buildings to collapse and triggering landslides across northern Luzon Island.

Rescue workers evacuating people from a collapsed building on Luzon Island following a Magnitude 7.0 Earthquake on 27 July 2022. Philippines Bureau of Fire Protection.

The geology of the Philippines is complex, with the majority of the islands located on the east of the Sunda Plate. To the east of this lies the Philippine Sea plate, which is being subducted beneath the Sunda Plate (a breakaway part of the Eurasian Plate); further east, in the Mariana Islands, the Pacific Plate is being subducted beneath the Philippine Sea Plate. This is not a smooth process, and the rocks of the tectonic plates frequently stick together before eventually being broken apart by the rising pressure, leading to Earthquakes in the process. Material from the subducting Philippine Plate is heated by the temperature of the Earth's interior, causing lighter minerals to melt and the resultant magma to rise through the overlying Sunda Plate, fuelling the volcanoes of the Philippines.