The United States Geological Survey recorded a Magnitude 5.5 Earthquake at a depth of 34.3 km roughly 37 km offshore of Zambales Province on southwestern Luzon Island, the Philippines, slightly after 5.45 pm local time (slightly after 9.45 am GMT) on Sunday 17 June 2018. There are no reports of any damage or injuries associated with this event, though it was felt across much of the southwestern part of Luzon.
The approximate location of the 17 June 2018 Zambales Earthquake. USGS.
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.
Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.
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