Magnitude 7.1 Deep-Focus Earthquake Strikes Off Sabah Coast, Felt Widely

An earthquake preliminarily assessed by the United States Geological Survey (USGS) at magnitude 7.1 struck the waters off Malaysia's Sabah state in the early hours of Monday, February 23, 2026. The seismic event, which occurred at 12:57 a.m. local time, registered its epicenter less than 100 kilometers northeast of Kota Kinabalu at a depth of approximately 619.8 kilometers. This places the event within the seismological definition of a deep-focus earthquake, characterized by hypocenters exceeding 300 kilometers, typically occurring within subducted oceanic lithosphere at convergent boundaries.

The extreme depth of this intraslab earthquake was the critical factor in mitigating widespread hazard. The U.S. Tsunami Warning Center confirmed that no alerts were issued following the tremor, and the USGS assessed the likelihood of shaking-related fatalities and economic losses as low, issuing a Green alert. Local authorities in Sabah, including the Sabah Fire and Rescue Department, reported no major incidents or casualties in the immediate aftermath, though patrols were maintained for surveillance.

The Malaysian Meteorological Department (MetMalaysia) recorded the tremor at a slightly lower magnitude of 6.8, locating the epicenter approximately 49 kilometers west of Kudat at a depth of about 678 kilometers. Despite the offshore location and significant depth, the seismic energy propagated across a vast area. Reports confirmed shaking along Sabah's west coast, through Sarawak, and into Peninsular Malaysia. Residents in Singapore, located over 1,500 kilometers away, also reported feeling the shaking shortly after 1:00 a.m.

This wide felt area is characteristic of deep-focus events, which transmit energy across broader regions even if they cause less surface destruction than shallow quakes. This event represents the most powerful earthquake recorded near Malaysia since a magnitude 6.6 quake occurred near Lahad Datu in 1923. Malaysia’s seismic activity is influenced by active subduction zones such as the Philippine Trench and Sulu Trench, while Peninsular Malaysia is indirectly affected by stress from the Sunda Subduction Zone off western Sumatra.

A geological study from October of the previous year had previously identified six Malaysian states, including Sabah and Sarawak, as being at higher earthquake risk. The mechanics of such deep intraslab events, often linked to dehydration embrittlement within the subducting slab, are complex and rare beneath Borneo but capable of producing wide-area effects. Authorities across the region, including MetMalaysia, affirmed they will continue to monitor seismic developments closely. The low damage assessment is directly attributed to the profound depth, as tsunamis are not generated by earthquakes at such levels, underscoring the importance of the government's regional Seismic Hazard Map for setting building standards.