DAVAO CITY (MindaNews / 15 August 2026) – August 17, 2026 marks the 50th anniversary of the Magnitude 8.2 quake that struck at 12:11 a.m. and triggered a tsunami along the Moro Gulf that, according to a 1978 report for the Special Committee on Tsunami Warning System prepared for the National Committee on Marine Sciences and National Science Development Board, left at least 8,000 dead or missing, some 10,000 injured and about 90,000 homeless.
If a tsunami happens again in this area, would residents and local governments know what to do? Are disaster preparedness plans in place?
The 1978 report, written by Jesuit priest Victor L. Badillo and Zinnia C. Astilla of the Manila Observatory, was intended primarily to “present findings about this tsunami for a better understanding of it and that steps may be taken to lessen loss to lives and property in future tsunamis.”
It was “the most disastrous tsunami experienced by the Philippines,” affecting 700 kilometers of coastlines bordering the Moro Gulf,” the report said. Ninety-five per cent of the casualties, the report said, were “due to the tsunami.”
The report recommended that “for the future, plans should aim for evacuation to higher ground within five minutes of a violent earthquake.”
The report noted that there had been “more severe tsunamis, but areas hit were less populated and had less man-made structures.”
“A natural disaster is not merely a geophysical event but a human one as well. If any projection can be made it is this: What is now barren will be densely populated. Empty beaches will be filled with residences, tourist facilities, hotels, factories, power plants, etc.. Offshore, there will not be merely seaweed and oyster farms and fish corrals but also storage facilities, tank farms and the like. Thus, a tsunami prone coast is potentially a great disaster area.”
Tsunami drills
Fifty years after the 1976 tsunami, the Moro Gulf areas are now densely populated, beach resorts and other business establishments have lined its shorelines.
The tsunami waves in 1976 ranged from 4.3 meters (14 feet) to nine meters (29 feet).
Waves were reported to be higher than five meters in Linek, Datu Odin Sinsuat in Maguindanao del Norte and in Kalanganan in Cotabato City, Pagadian City, Sacol Island in Zamboanga City. “At Lebak (in Sultan Kudarat), waves may have been as high as nine meters,” the report added.
The City Disaster Risk Reduction and Management Council (CDRRMC) of one of the hardest hit areas in 1976 – Pagadian City — has been holding earthquake and tsunami drills for some years now.
On July 1, 2026, Pagadian City held a Community-Based Tsunami Evacuation Planning Seminar and Workshop at the Asenso Convention Center to strengthen the communities’ preparedness through proper tsunami evacuation planning and disaster preparedness.
Earthquake and tsunami drills have also been conducted in areas along the Moro Gulf within the Bangsamoro Autonomous Region in Muslim Mindanao.
On August 17, 2019, Kutangbato News reported on BARMM-READI’s multi-hazard exercise, a simulation of a strong earthquake followed by a tsunami similar to 1976.
An August 18, 2015 report of GMA News on a tsunami and earthquake drill in Pagadian City, described the exercise: “Sirens signaled residents to evacuate low-lying areas and to move to higher points to avoid danger. Medical teams were always in place in the evacuation areas to assist ‘victims’ while local government units’ vehicles went around low-lying areas to pick up residents.”
On July 8, 2026, Phivolcs posted on its social media page about their campaign to build a “Tsunami-Ready Palimbang” in Sultan Kudarat province.
The 3R (Risk Reduction and Resilience) Tsunami Ready Community Information Campaign on July 7, 2026, brought together the Municipal Disaster Risk Reduction and Management Office and representatives from the 25 tsunami-at-risk barangays to strengthen community preparedness and resilience.
The 3R (Risk Reduction and Resilience) Tsunami Ready program is a collaborative initiative led by DOST-PHIVOLCS alongside local disaster agencies to help coastal communities meet the 12 international indicators set by the UNESCO-IOC Tsunami Ready Recognition Programme (TRRP).
Local inundation maps
Among the 12 indicators are the mapping and designation of tsunami hazard zones, easily understood tsunami evacuation maps, and tsunami information including signage publicly displayed.
In its recommendations, the 1978 report on the Moro Gulf tsunami said “an immediate and realizable goal is to require local officials to prepare local inundation maps” which are basically “a street map of a town with dangerous areas to be evacuated crosshatched.”
“These maps can be drawn empirically by knowing which areas were inundated by past tsunamis. If there are contour maps available, one can determine all areas below a chosen height above sea level, for example six meters, as places to be evacuated,” the report said.
The maps, it added, could also be useful to “engineers, architects, land use planners, building code drafters, insurance agencies and the like.”
June 8, 2026 quake
When a Magnitude 7.8 earthquake struck parts of Mindanao at 7:37 a.m. off Sarangani on June 8, Phivolcs issued Tsunami Information No. 1 for all coastal communities in the provinces of Sarangani, Basilan, Davao Occidental, South Cotabato, Sultan Kudarat, Sul, Tawi-Tawi, Zamboanga del Sur and Zamboanga Sibugay, to immediately evacuate.
The Tsunami Information No. 1 was posted on Phivolcs’ social media page at 7:56 a.m. or 19 minutes after the earthquake struck.
Between 7:45 A.M and 9:30 a.m., Phivolcs monitored tsunamis in Kiamba, Sarangani province, Zamboanga City, Mati City in Davao Oriental, and Tandag City in Surigao del Sur but their wave heights (0.09 to 1.48 meters) were “too small to cause damage,” so Phivocs lifted the warning at 3:19 p.m.
But residents in coastal towns vulnerable to tsunamis need not wait for the Phivolcs to issue a warning.
The 1978 report stressed that it is “impossible” for a national agency to provide warning to inhabitants about to be hit by a tsunami generated by a local earthquake. “It would be fatal to wait for a radio broadcast and the like before moving into action,” it said.
With the advances in telecommunications half a century after the 1976 tsunami, it is now possible for a national agency like Phivolcs to warn residents about an impending tsunami. But it is not as quickly. Phivolcs issued the tsunami warning also at 7:37 a.m., shortly after the Magnitude 7.8 quake, and cancelled it at 3:19 p.m. through Tsunami Information 2.
Natural signs
The 1978 report had stressed that residents need not wait for a warning or siren. “There is already a warning available, one provided by nature herself – the violent shock of an earthquake. If the shock is violent enough so that it is difficult to stand or walk then it is time to seek higher ground at once. Going to a higher ground will not mean going a long distance if local inundation maps exist and are known,” the report said.
But the report also noted that “it is one thing to have these maps and quite an altogether different thing for people to use them. What becomes clear is that education is needed, an extremely difficult task, a never finished task.”
Phivolcs has a section on hazard maps for earthquakes, including tsunami, and volcanoes. But a check for tsunami hazard maps for Barangays Linek and Kusiong in Datu Odin Sinsuat and Barangays San Pedro and Sta. Lucia in Pagadian City – among the hardest hit in 1976 and whose tsunami wave heights ranged from 3.7 to 4.3 meters yielded a similar response: “Please contact PHIVOLCS for specific hazard map.”
There is no Bangsamoro Autonomous Region in Muslim Mindanao (BARMM) in the section on hazard maps. The region indicated is its predecessor, the Autonomous Region in Muslim Mindanao, which was abolished in 2019 when Republic Act 11054 or the Organic Law for the BARMM was ratified in a plebiscite, and the BARMM was established in its stead.
Shake, Drop, Roar
But while the Phivolcs lifted its tsunami warning on June 8, 2026, it also reminded residents in coastal communities that “in the event of strongly felt aftershocks,” they should “recognize the natural signs of an impending local tsunami.”
“Shake, Drop and Roar,” it said.
“Shake” refers to a strong earthquake, “drop” refers to the sudden rise or fall of seawater, and “roar,” refers to the sound of incoming waves.
“If ANY of these signs are observed, immediately evacuate to higher ground for safety,” Phivolcs said. (Carolyn O. Arguillas / MindaNews)
READ
Moro Gulf Tsunami of August 17, 1976
35 years after the 1976 Moro Gulf tsunami: whatever happened to the preparedness plans?
Babu Minang, survivor of 1976 tsunami: “Nothing was left”
The 1976 tsunami: Maguindanao had highest death toll
PERSONAL ESSAY: The 1976 tsunami was a life-changing experience
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