Magnitude 6.1 earthquake struck Luzon, Philippines

Strong earthquake with magnitude 6.1 struck Luzon, Philippines on June 16, 2012 at 22:18 UTC according to USGS. Epicenter was located 94 km (58 miles) SW of Dagupan, Luzon, Philippines (15.574°N, 119.609°E). Recorded depth was 35.3 km (21.9 miles).

Philippine Institute of Volcanology and Seismology  – PHIVOLCS is reporting 6.0 earthquake. No damage is expected from this one. Aftershocks are expected.

Magnitude	6.1
Date-Time	Saturday, June 16, 2012 at 22:18:48 UTC Sunday, June 17, 2012 at 06:18:48 AM at epicenter
Location	15.574°N, 119.609°E
Depth	35.3 km (21.9 miles)
Region	LUZON, PHILIPPINES
Distances	94 km (58 miles) SW of Dagupan, Luzon, Philippines 109 km (67 miles) NW of Olongapo, Luzon, Philippines 115 km (71 miles) WNW of Angeles, Luzon, Philippines 182 km (113 miles) NW of MANILA, Philippines
Location Uncertainty	horizontal +/- 11.1 km (6.9 miles); depth +/- 6.6 km (4.1 miles)
Parameters	NST=294, Nph=299, Dmin=817.1 km, Rmss=0.96 sec, Gp= 22°, M-type=regional moment magnitude (Mw), Version=B
Source	Magnitude: USGS NEIC (WDCS-D) Location: USGS NEIC (WDCS-D)
Event ID	usb000ahkr

 

Shake map

Population exposure

Selected cities exposed from GeoNames database of cities with 1,000 or more residents.

MMI	City	Population
IV	Bani	3k
IV	Bolitoc	3k
IV	Lipay	3k
IV	Taltal	5k
IV	Palauig	3k
IV	Lucapon	6k
III	Manila	10,445k
III	Makati	0
III	Pasig	0
III	Tabuk	27k
III	Kabugao	2k

Historical seismicity – 2012

This area is on the Manila Trench, an oceanic trench in the South China Sea, located west of the islands of Luzon and Mindoro in the Philippines. The trench reaches a depth of about 5,400 metres (17,700 ft), in contrast with the average depth of the South China Sea of about 1,500 metres (4,900 ft). It is created by subduction, in which the Sunda Plate (part of Eurasian Plate) is subducting under the Philippine Mobile Belt, producing this almost N-S trending trench. Theconvergent boundary is terminated to the north by the Taiwan collision zone, and to the south by the Mindoro terrane (Sulu-Palawan block colliding with SW Luzon). It is an area pervaded by negative gravity anomalies.

The Manila Trench is associated with frequent earthquakes, and the subduction zone is responsible for the belt of volcanoes on the west side of the Philippine island of Luzon, which includes Mount Pinatubo.

Convergence between the Philippine Mobile Belt and the Sunda Plate have been estimated using GPS measurements, and this value ranges from ~ 50+ mm/yr in Taiwan, to 100 mm/yr near N. Luzon, and ~ 50 mm/yr near Zambales and ~20+mm/yr near Mindoro island. Plate locking between the Sunda Plate and Luzon is about 1% coupled, almost unlocked as determined by elastic block models, suggesting that the trench absorbs the Philippine Mobile Belt-Eurasian Plate convergence.

Featured image: Google Earth + USGS