A Catastrophe Struck the City: Moro Gulf Earthquake and Tsunami

On August 16, 1976, an earthquake which was believed to have originated from the Cotabato Trench struck the isaland of Mindanao. Aggravating the earthquake’s disastrous event is the simultaneous emergence of a tsunami which was generated from the Gulf of Moro and the Celebes Sea.

It was the worst earthquake and tsunami in the history of the Philippines. It killed about 8,000 people in the coastal communities of North and South Zamboanga, North and South Lanao, North Cotabato, Maguindanao and Sultan Kudarat. An estimated number of victims for this tragedy left 5,000 dead, 2,200 missing or presumed dead, more than 9,500 injured and a total of 93,500 people were left homeless.

PAGASA identified the earthquake magnitude as intensity VI for the city.

Similarly, the Pacific Tsunami Warning Center (PTWC) in Honolulu issued a Tsunami Watch for the Pacific and queried tide gauge stations in Okinawa, Yap and Malakal. Due to negative reports from these stations, the watch was cancelled. Unfortunately, minutes after the earthquake’s emergence, a large local tsunami struck the region. Therefore, due to the unexpected outcome, there was no time to issue a local warning.

Based on the survey, it was determined that the maximum height of the tsunami waves in the entire Moro Gulf were in the order of 4.5 meters (14-15 feet), which was considerably less than what had been reported in the newspapers before. Such large waves occurred at Alicia, Bongo Island, Lebak, Resa, east coasts of Basilan, Jolo Islands and Pagadian City.

Pagadian City was the major city in the area that was struck by both the earthquake and the tsunami and sustained the greatest number of casualties.

The survey of Pagadian City and of the vicinity included measurements of the horizontal and vertical extent of inundation, observations on the failure of structures and buildings, collection of information on the seismic affects, interviews of eyewitnesses and officials, and observations on the response of the people to the disaster. Statistical information was gathered on loss of life and property.

According to the stories of the people, during the disaster, the people were evacuated to a higher vicinity. It was a school before, but today, is now more commonly called the Pagadian City Gymnasium. People who were able to survive the event can still remember in their minds the unpleasant memory brought by the catastrophe.

The city lost large amounts of properties and the disaster was something that the people won't ever hope to experience again.