A TOTAL of 16 earthquakes were felt in Davao Region between August and September this year, said Engr. Eduardo Lauron of the Philippine Institute of Volcanology and Seismology (Phivolcs) in Davao on September 30.
Two of these earthquakes occurred on August 30 and 15 and were categorized as strong types of earthquakes.
A magnitude of 5.9 was recorded on August 30 with the epicenter located in Maguindanao while a magnitude 5.5 quake took place on August 15 centered in the municipality of Matanao, Davao del Sur province.
Lauron said Davao City felt an intensity 5 quake brought by the August 15 event.
“For August, ang events umabot ng nine recorded dito sa Davao Region mismo (we recorded nine events in Davao Region). Mostly nasa (in) Davao O cidental and parts of Davao del Sur,” he said.
On the other hand, seven earthquakes were recorded in September, most of which were of low intensity including a 3.3 magnitude quake in Davao del Sur.
Lauron said the seven quakes were recorded in the municipality of Tarragona in Davao Oriental, the municipality of Jose Abad Santos in Davao Occidental, and parts of Davao del Sur.
Tectonic plate movements usually trigger an earthquake event but according to Lauron, a number of fault systems are also a generator of earthquakes in Davao Region.
"The tectonic plate (moves) with the Philippine Sea plate, binabangga ang Pilipinas (bumping against the country). And the China Sea plate, binabangga ang (bumps against the) western part of our archipelago (and) squeezes the Philippines thus generating sufficient amount to trigger movement along the faultlines,” Lauron said.
He mentioned that the continuous movement of the Philippine Trench, located on the eastern side of the country, also causes quakes in Davao Occidental and Davao Oriental.
However, Davao Region and Mindanao have generators called inland fault systems that also trigger an earthquake. Lauron said these generators are the Cotabato fault system, Nabunturan fault system, and the Davao fault system which is composed of five faults within Davao City. ICM