Earthquakes are ruthless destroyers of human and animal life as well as private and public property. They strike without any warning and without discrimination. Anybody can be a victim – he or she only has to be at the wrong place at the wrong time. Despite huge technological advances achieved in this ultramodern world, not one scientist, researcher, inventor, or innovator out there has successfully come up with an instrument to accurately predict where and when the next big earthquake would strike.
Thus earthquakes are among the most terrifying events one could ever experience. The major earthquakes – the foremost in terms of magnitude and casualties – that struck the Philippines from the 1960's to present ranged from 6.1 to 7.9 magnitude and killed from 6 to about 8,000 people.
The 1976 Moro Gulf Earthquake in southern Mindanao with a magnitude of 7.9 and which claimed the lives of up to 8,000 persons is by far the worst earthquake in the Philippines with regard to strength of ground shaking and death toll. A large part of the deaths, injuries, and missing persons were presumably swept to the sea and devoured by sharks as the powerful earthquake was tsunamigenic, or it generated a tsunami. Both the earthquake and subsequent tsunami struck while the unsuspecting residents were fast asleep.
At magnitude 7.8, the second strongest of the killer earthquakes since the 1960's took place in Northern and Central Luzon in 1990. Most adversely affected were the cities of Baguio, Dagupan, and Cabanatuan which saw the collapse of multiple storey buildings, resulting to the deaths of more than 2,000 persons.
The third strongest was the 7.3 magnitude earthquake with epicenter in Casiguran, Aurora in 1968. The strong tremor was felt a few provinces away – in Manila – where a six-storey building, the Ruby Tower, collapsed, inflicting injuries and instant death to at most 271 persons.
The 2013 earthquake that occurred in the Central Visayas provinces of Bohol, Cebu, and Siquijor brought death and injuries to numerous people and destruction or damage of buildings including the precious centuries-old churches. It was a magnitude 7.2 earthquake.
These 4 earthquakes just described together with 8 more are listed in the following table which summarizes such details as location, time/date of occurrence, surface magnitude, epicenter, depth, and casualties (dead/missing).
|Location||Time and date occurrence||Surface Magnitude (Ms)||Epicenter||Focal depth (km)||Casualties|
|Moro Gulf, Mindanao||7.9||In the Celebes Sea between the islands of Mindanao and Borneo||7||7,079-8,000||–|
|Northern/Central Luzon||7.8||Near the town of Rizal, Nueva Ecija||25.1||2,412||–|
|Casiguran, Aurora||7.3||Casiguran, Aurora||25||207-271||–|
|Bohol/Cebu/Siquijor||7.2||Near boundary of municipalities Sagbayan and Catigbian||12||222||8|
|Oriental Mindoro||7.1||11 kilometers NW of Baco, Mindoro near Verde Island||78|
|Negros/Cebu||6.7||Approximatley 5 kilometers northeast of Tayasan, Negros Oriental||10||51||62|
|Laoag, Ilocos Norte||6.5||Approximately 30 kilometers east-northeast of Laoag City||5-10||16||–|
|Pampanga/Zambales||6.1||18 kilometers east of Castillejos, Zambales||10||21||–|
|Palimbang, Sultan Kudarat||6.8||About 81 kilometers SW of Isulan, Sultan Kudarat||15||15|
|Panay||7.1||Vicinity of Culasi, Antique||15||8|
|Surigao del Norte||6.7||Surigao Strait||10||8|
|Bohol/Cebu||6.8||About 17 kilometers east of Tagbilaran City||6|