1990 Luzon earthquake
The 1990 Luzon earthquake occurred on July 16 at 4:26 p.m. (PDT) or 3:26 p.m. (PST) on the densely populated island of Luzon in the Philippines. The shock had a surface wave magnitude of 7.8 and produced a 125 km-long ground rupture that stretched from Dingalan, Aurora to Kayapa, Nueva Vizcaya. The event was a result of strike-slip movements along the Philippine Fault and the Digdig Fault within the Philippine Fault System. The earthquake's epicenter was near the town of Rizal, Nueva Ecija, northeast of Cabanatuan.[6] An estimated 1,621 people were killed,[7][8] most of the fatalities located in Central Luzon and the Cordillera region.
Geology[edit]
The Philippine archipelago represents a complex plate boundary between the Philippine Sea and Eurasian plates. To the east, oceanic lithosphere subducts westwards beneath the islands along the Philippine Trench. Off the west coast of Luzon, the Manila Trench accommodates eastward subduction. To its east is the East Luzon Trench, a convergent boundary that separates the Philippine Trench by a transform fault. The left-lateral strike-slip Philippine Fault System runs through the islands. It is one of the longest strike-slip faults in the world. Understanding of its geology and earthquake history is limited. It extends north–south for 1,300 km (810 mi) from Mindanao to northern Luzon. On Luzon, the fault branches into multiple splay segments including the northernly trending Digdig Fault.[9]
The event was one of the largest continental strike-slip earthquakes of the century. It was associated with a 125 km (78 mi) long surface rupture on the Philippine Fault System. Rupture occurred bilaterally, extending from the hypocenter, but most of the rupture occurred northwest for 75–100 km (47–62 mi). About 25 km (16 mi) north of the epicenter, the largest slip was estimated at 10–15 m (33–49 ft). Slip gradually decreased away from the zone. The Digdig Fault displayed 5–6 m (16–20 ft) of left-lateral displacement. Aftershocks occurred along a 100 km (62 mi) length of the fault. They displayed a range of focal mechanism including strike-slip, normal and thrust faulting.[10]
Aftermath[edit]
The University of Baguio, which got struck by this earthquake, was rehabilitated, while the land where Hyatt Terraces stood remains abandoned.[32]
In popular culture[edit]
The earthquake is featured in the television documentary series by GRB Entertainment, aired on The Learning Channel and other television channels around the world, about natural disasters titled Earth's Fury (also known internationally as Anatomy of Disaster) in an episode entitled "Earthquake!",[33] the 50th anniversary special of GMA News and Public Affairs titled Limang Dekada in 2010,[34] the 50th anniversary special of ABS-CBN titled Sa Mata ng Balita in 2003,[35] and the 1996 documentary produced by Langley Productions titled The Amazing Video Collection: Natural Disasters.
Scenes of the earthquake's destruction around Baguio, as well as reflections on Filipino people's capacity to endure and rebuild, also featured in a segment of 1994 collage film directed by National Artist Kidlat Tahimik titled Why is Yellow the Middle of the Rainbow?.