The 2010 Mentawai earthquake occurred with a moment magnitude of 7.8[1] on 25 October off the western coast of Sumatra at 21:42 local time (14:42 UTC).

It was widely felt across the provinces of Bengkulu and West Sumatra and resulted in a substantial localized tsunami that struck the Mentawai Islands.

[6][7] The earthquake occurred around 150 miles (240 km) west of Bengkulu, close to the Mentawai Islands, southwest of South Pagai.

[1][10] Unlike in 2004, the tsunami caused by the October 2010 earthquake did not propagate westwards and other Indian Ocean nations were unaffected.

[15] According to a spokesperson for the Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG), the quake was felt in several mainland towns, but no damage or deaths were reported.

[3] Relief teams were initially unable to reach the islands due to poor weather conditions and rough seas.

[3] The subsequent relief effort was hampered by bad weather[14] and the remoteness of the islands, which led to delays in the reporting of casualties.

[30] An alert was broadcast from radios and mosque loudspeakers on the mainland, prompting thousands to flee to higher ground.

[32] However, the epicentre of the earthquake was so close to the islands that a warning would probably have been too late in any case, as the tsunami only took about five to ten minutes to reach Pagai.