The 7.7 magnitude earthquake and resulting tsunami that struck Monday off of Pagai Selatan Island, one of the Mentawai Islands off the west coast of Sumatra Island, have reportedly left 400 people dead, hundreds still missing, and an estimated 13,000 homeless.

Farther away from the epicenter, the tsunami wave dissipated rapidly to increases of only 10 to 40 cm in amplitude as recorded at tide gauges on Cocos Island, Enggano Island, Tanahbalah Island, Padang, Hanimaadhoo, Rodrigues, and Port Louis, for example. Assistant Director General of UNESCO and Executive Secretary of the Intergovernmental Oceanographic Commission Dr.

Wendy Watson-Wright, confirmed that the alerts issued from the Pacific Tsunami Warning Center the Japanese North West Pacific Tsunami Advisory Center, and the Indonesian Tsunami Early Warning System functioned as intended to alert governments of the situation within minutes of the natural disaster. The PTWC cancelled the regional watch 2 hours and 15 minutes after the earthquake. The center cautioned however that rapid changes and variations in currents in the region could continue for several hours following the seismic event and that boats and coastal structures should monitor the advice of local authorities.