In commemoration of the 50th anniversary of the M8.1 August 17, 1976 Moro Gulf Earthquake and Tsunami, the Department of Science and Technology–Philippine Institute of Volcanology and Seismology (DOST-PHIVOLCS), in partnership with the Ministry of Science and Technology–Bangsamoro Autonomous Region in Muslim Mindanao (MOST-BARMM) and the City Government of Cotabato, unveiled a tsunami commemorative marker at Rizal Park, Cotabato City, on August 26, 2026.
On August 17, 1976, the movement along the Cotabato Trench generated a magnitude 8.1 earthquake in the Moro Gulf. This offshore earthquake triggered a 9-m-high tsunami that affected coastal communities and resulted in approximately 8,000 casualties. Most of the structural damage was concentrated in Cotabato City, where shallow marine deposits of the Cotabato Basin contributed to the amplification of ground shaking and, in some areas, liquefaction.
The Cotabato Trench remains an active source of earthquakes that have the potential of generating tsunamis in the Philippines, with significant earthquakes recorded in 1871, 1976, 2002, 2023, and 2026, highlighting the continuing earthquake hazard in the region.
DOST-PHIVOLCS Director Teresito Bacolcol emphasized, “This marker is a standing mandate for proactive safety. We cannot stop an earthquake from happening, but we have full control over how we build, plan, and prepare. It serves as a daily call to strictly enforce building and structural codes, utilize hazard mapping, and prioritize disaster readiness in every community. Science gives us foresight, but community action ensures our resilience.”
The tsunami marker at Rizal Park serves as a reminder of Cotabato City’s experience during the 1976 disaster and the continuing need for communities to understand hazards and remain prepared.
This is the 2nd marker installed this year following the unveiling of the tsunami marker in Lebak, Sultan Kudarat, last August 17, 2026. DOST-PHIVOLCS hopes that this tsunami marker will forever honor those we lost and inspire us to build a safer and more resilient communities for generations to come. The Institute continues to work with local government units and other partners to science-based information on earthquakes and tsunami and to strengthen disaster preparedness among communities.
