Tsunamis

Indian Ocean tsunami

On 26 December 2004, an earthquake, measuring 9.0 on the Richter scale, occurred off the coast of western Sumatra, Indonesia and generated a massive and destructive tsunami. The tsunami took less than 2 hours to reach Thailand and Sri Lanka, 3.5 hours to get to the Maldives and nearly 8 hours to arrive in East Africa. Tidal disturbances were reported on the North West coast of Australia. See the Animation of the Indian Ocean Tsunami - Global in the News below. The death toll now stands at more than 250,000. Before and after images compare 2004 and 2014, including reconstructing the forecourt of the Aceh mosque shown in the photograph.

The last transoceanic tsunami to hit the region was in 1882, and this was caused by Krakatoa's eruption in Indonesia. Other large earthquakes along the Sumatra trench had not caused major tsunamis, or if they had, they had not been reported as devastating. Outside the Pacific, no tsunami warning systems or centres existed at the time, although the tsunami hazard has long been known to exist on both sides of the Atlantic Ocean, in the Mediterranean, Caribbean and Black Seas and in the eastern Indian Ocean.

A further tsunami struck the south coast of Java, Indonesia on 17 July 2006. It was triggered by an undersea earthquake of magnitude 7.7 to the south of Java island. While the death toll is much lower than in the 2004 tsunami, at least 50 000 people have been displaced. An Indian Ocean tsunami warning system has been developed and there appear to have been some alerts.

Pacific Tsunamis

Tsunamis, one of the most destructive forces of nature, are described in general terms. IOC co-sponsors an information center and warning system for tsunamis in the Pacific and organizes relevant training and infrastructure building for Member States in that region.

An earthquake in Samoa, measuring 7.9 on the Richter scale struck at 1748 local time (UTC) on 29 September 2009. It was centred at 15 deg S and 171 deg W, in the Samoa Islands Region at a depth of about 35 km. The Pacific Tsunami Warning Center warned that the quake was likely to have generated a tsunami. The initial warning covered American Samoa; Samoa; Niue; Wallis-Futuna; Tokelau; Cook Islands; Tonga; Tuvalu; Kiribati; Kermadec Is; Fiji; Howland-Baker; Jarvis Is.; New Zealand; French Polynesia; and Palmyra Is. There are early reports of 95 deaths and widespread damage in Samoa and American Samoa although the alert has been downgraded in the broader South Pacific region. <br
A previous tsunami occurred when an 8.0-magnitude undersea quake struck at 0740 local time on 3 April 2007 (2040 GMT 2 April), near New Georgia in the Solomon Islands, and was followed by a tsunami which brought huge waves crashing down on the coastline of this remote Pacific region. Most of the 28 known victims were in Gizo, a small fishing town and diving centre only 45km (25 miles) from the epicentre of the quake. Many of the town's buildings and infrastructure have been destroyed.

The tsunami has rekindled the debate about warning systems. Some experts said they were of little use if the affected areas [of earthquake and tsunami] were so close, as with Monday's quake. But UN special coordinator for the early warning system in Indonesia, Michael Rottmann, said even a warning of 10 minutes could save 'a lot of lives'. Story courtesy BBC News: Asia-Pacific

Samoa 29 September 2009

More images from American Samoa courtesy the BBC; some showing people who had enough warning to escape to higher ground.

Chile 27 February 2010

 

A large earthquake of magnitude 8.8 struck near the central coast of Chile on 27 Feb 2010 at 06:34 hr UTC. Latitude: 36.1� S Longitude: 72.6� W The depth was 55 km (34.2 mi). At least 789 people are dead; the death toll would have been much higher except for the location of the quake and the strict building codes in Chile, a zone of frequent earthquakes. A tsunami struck Concepción and adjacent areas of the Chilean coast and generated an alert throughout the Pacific rim and oceanic islands. The tsunami was not as destructive as initially feared on distant shores but caused substantial damage to fishing boats, infrastructure and coastal towns in the local area.

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