Tsunami warning after 7.4 earthquake off Philippines: What we know

A magnitude 7.4 earthquake has struck off the coast of the southern Philippines, killing at least two people and prompting a tsunami warning for the country and some regions of Indonesia, according to local authorities. The tsumani alert has since been lifted.

The earthquake comes just 10 days after another deadly earthquake hit the central Philippines, killing at least 79 people and injuring hundreds.

Here is more about what has happened and why the country is so vulnerable to earthquakes and natural disasters.

The earthquake struck at a depth of 43 kilometres (27 miles) at 9:43am local time (01:43 GMT) on Friday, off the coast of Manay town in Davao Oriental in the Mindanao region of the southern Philippines, according to the Philippine Institute of Volcanology and Seismology (Phivolcs).

Phivolcs said the earthquake had been caused by movement in the Philippine Trench at a depth of 23 kilometres (14 miles). The Philippine Trench is a long, narrow depression in the ocean. It is located to the east of the Philippines.

Phivolcs also warned of aftershocks and issued a tsunami warning for the surrounding region, saying it expected waves larger than 1 metre (3.3ft). Coastal residents have been “strongly advised to immediately evacuate to higher grounds or move farther inland”, the agency said soon after the earthquake struck.

The United States National Tsunami Warning Center also issued tsunami warnings to parts of Indonesia and Palau, expecting waves of 0.3 to 1 metre (1-3.3ft) above tide level in these regions.

However, at about noon in the Philippines (04:00 GMT), the Pacific Tsunami Warning Center in Honolulu said the tsunami threat had passed, according to the Reuters News Agency.

Indonesia’s Meteorology, Climatology and Geophysics Agency said it had detected small tsunami waves in North Sulawesi province with heights ranging from 3.5 to 17 centimetres (1.3 to 6.7 inches) in Melonguane, Beo, Essang and Ganalo in the Talaud Islands districts. The agency has since lifted its tsunami warning.

Davao Oriental governor Nelson Dayanghirang told the Philippines’ ABS-CBN news channel that at least two people had died as a result of the earthquake.

“So far, we have recorded two casualties, and we have evacuated the patients to our hospital, provincial and district hospitals,” he said. At least 250 patients were also evacuated from a damaged hospital and are to be housed in tents, he added.

Richie Diuyen, a disaster official in Manay, close to the epicentre, said the quake lasted for 30-40 seconds and some houses, the facade of a church, roads and bridges were damaged.

“We couldn’t stand earlier. I am 46 years old now, and this is the strongest earthquake I ever felt,” Diuyen told the Reuters news agency.

“The damage is quite big,” she added.

The governor of Davao Del Norte told Philippines’ radio station DZMM that people and employees in the region’s capital Tagum “are really panicking”.

“And there are also buildings with damage that have been reported [to us],” he added.

ABS-CBN reported that students at Bukidnon State University in Malaybalay City rushed out of their classrooms when the quake struck. Schools were also closed in many areas.

Jun Saavedra, a disaster-mitigation officer of Governor Generoso town in Davao Oriental, told The Associated Press that power was cut after the earthquake.

“I was driving my car when it suddenly swayed and I saw powerlines swaying wildly. People darted out of houses and buildings as the ground shook and electricity came off,” he said.

Philippines’ President Ferdinand Marcos Jr said a search and rescue mission has been deployed to affected regions.

He warned people to “follow all instructions” from local disaster authorities. “Your safety is our top priority,” he said.

The president added that the Department of Social Welfare and Development (DSWD) plans to send food and other aid items to affected areas, and said that the Department of Health (DOH) will provide medical help.

The Office of the Vice President said its Mindanao satellite offices are ready to assist people and also provide psychological help to people and young children who are scared or anxious after the earthquake.

The Philippines lies in the Pacific Ring of Fire, a tectonic belt of volcanic arcs and oceanic trenches in the Pacific Ocean.

John Dale B Dianala, assistant professor at the National Institute of Geological Sciences, the University of the Philippines in Diliman, told Al Jazeera that just by virtue of the geographic and geologic setting of the country, the Philippines is home to many onshore and offshore tectonic faults.

“The whole length of the Philippines, around 1,800km, is right along the boundary of two major tectonic plates – the Philippine Sea plate and Eurasian plate – part of the so-called Pacific Ring of Fire. These two plates, thousands of kilometres wide, have been pushing against each other for millions of years at two to three times the rate of fingernail growth,” he said.

“Each earthquake is a manifestation of the periodic release of the stress along long fractures on these plates – what geologists call ‘faults’ – which rupture several metres of movement along a fault in large earthquakes.

“When the displacement involves vertical uplift of the seafloor from an offshore fault, like in the Philippine Trench to the east of the country, the movement displaces the water column from the depths of the ocean that then propagate to the surface and coasts in the form of tsunamis. Strong shaking can also cause submarine landslides that can also trigger tsunamis,” he added.

According to Dianala, another big issue the country faces is the cascading effect of different natural hazards.

“The week after the earthquake in Cebu, we had floods and another earthquake in Mindanao. At some point, resources can get spread thinly,” he said.

Indonesia, New Zealand, Japan, the United States, Canada, Russia, Guatemala, Peru and Chile are also countries located within the Ring of Fire.

While Phivolcs and the United Nations have been building systems to alert people about upcoming natural disasters, some politicians in the country say the president should be doing more.

According to ABS-CBN, after Friday’s earthquake, Jose Alvarez, a Filipino businessman and member of the country’s House of Representatives, said that if the government has extra income, it should be put into the “2025 budget” so that President Marcos Jr could access it and respond to natural disasters effectively.

“So that’s important in 2026, if we still have more earthquakes, more typhoons, more floods,” he said.

However, Dianala said the preparedness and resilience of the country to earthquakes has improved since the 1990s. Prior to that, an earthquake would have caused many more casualties and damage to infrastructure than has been caused this time.

“Earthquakes happen in the country relatively frequently, and that has led to disasters, unfortunately, but has also forced us to make sure we have proper laws and policies from lessons learned,” he said.

“The National Building Code of the Philippines has been revised to include provisions that require that buildings should not collapse under Intensity 8 shaking,” he noted. But he said how well these protocols are followed remains a question.