A strong earthquake shook Taiwan late on Saturday, marking the second major seismic event to hit the island in just a few days. The US Geological Survey (USGS) recorded the tremor at magnitude 6.6, while Taiwan’s Central Weather Administration assessed it slightly higher at 7.0. Early footage circulating online shows buildings swaying across Taipei as residents rushed outdoors, though officials have not reported casualties or damage so far.

The quake struck at 23:05 local time at a depth of about 73km off the coast of Yilan County, southwest of the capital. The Yilan County Fire Bureau confirmed that emergency teams had not received any distress reports immediately after the incident.

Taiwan, located along the boundary of major tectonic plates, frequently experiences significant seismic activity. Saturday night’s tremor follows a magnitude 6.0 quake that rattled the southeast of the island on Wednesday.

Recent activity in the region

The Philippine Sea also registered seismic movement on Saturday, with the National Center for Seismology (NCS) reporting a magnitude 6.6 earthquake at a depth of 65km. In a post on X, the NCS stated: "EQ of M: 6.6, On: 27/12/2025 20:35:56 IST, Lat: 24.64 N, Long: 122.12 E, Depth: 65 Km, Location: Philippine Sea."

Although vast and deep, the Philippine Sea connects tectonically with regions including Taiwan, Japan and the Philippines. Its seafloor consists of the Philippine Sea Plate, one of the world’s most active.

Why the region is highly vulnerable

The Philippines, Taiwan and Japan lie within the Pacific Ring of Fire, a zone known for frequent earthquakes and volcanic activity.

John Dale B Dianala, assistant professor at the National Institute of Geological Sciences at the University of the Philippines, told Al Jazeera that the country sits directly on the boundary of the Philippine Sea Plate and the Eurasian Plate.

He said: "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."

Dianala added: "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."

He also noted that vertical shifts of the seafloor during offshore quakes can push water columns upward, creating tsunami threats: "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."

Previous major earthquakes in Taiwan

Taiwan has suffered several destructive quakes in recent decades.

  • In April 2024, a 7.4-magnitude earthquake killed 17 people, triggered landslides and caused significant structural damage around Hualien.
  • Officials described it as the strongest quake the island had faced in 25 years.
  • The deadliest disaster on record remains the 1999 magnitude 7.6 earthquake, which killed more than 2,400 people.

Authorities continue to monitor the situation following Saturday’s tremor, while the first videos of the moment buildings began swaying across Taipei are now emerging online.

(With inputs from agencies)