INDIAN OCEAN: An earthquake of magnitude 4.2 struck the Indian Ocean on Sunday, a statement by the National Center for Seismology (NCS) said.
The earthquake struck at a depth of 90km. In a post on X, NCS said, "EQ of M: 4.2, On: 05/04/2026 05:39:28 IST, Lat: 5.305 N, Long: 93.972 E, Depth: 90 Km, Location: Indian Ocean." Earthquakes can occur anywhere between the Earth's surface and about 700 kilometres below the surface. For scientific purposes, this earthquake depth range of 0 - 700 km is divided into three zones: shallow, intermediate, and deep, as per USGS data.
Shallow earthquakes are between 0 and 70 km deep; intermediate earthquakes, 70 - 300 km deep; and deep earthquakes, 300 - 700 km deep. In general, the term "deep-focus earthquakes" is applied to earthquakes deeper than 70 km, the USGS states. Earlier on December 26, 2004, at 07:58:53 (local time), a magnitude 9.2-9.3 earthquake struck with an epicentre off the west coast of Aceh in northern Sumatra, Indonesia.
The undersea megathrust earthquake, known in the scientific community as the Sumatra-Andaman earthquake, was caused by a rupture along the fault between the Burma plate and the Indian plate, and reached a Mercalli intensity of IX in some areas. The earthquake caused a massive tsunami with waves up to 30 m (100 ft) high, known as the Boxing Day Tsunami after the Boxing Day holiday, or as the Asian Tsunami, which devastated communities along the surrounding coasts of the Indian Ocean, killing an estimated 227,898 people in 14 countries, especially in Aceh (Indonesia), Sri Lanka, Tamil Nadu (India), and Khao Lak (Thailand).
The direct result was severe disruption to living conditions and commerce in coastal provinces of these and other surrounding countries. It is the deadliest tsunami in history, the deadliest natural disaster of the 21st century, and one of the deadliest natural disasters in recorded history.