Earthquake and Tsunami activity in the Pacific Ring of Fire
Thu, Oct 1st 2009, 11:10
The Pacific Ring of Fire is one of the main zones of earthquake and tsunami activity in the world. Sumatra and Samoa lie within this zone and are the latest victims of the ring of fire.
Earthquakes and tsunamis have struck the Pacific region in the past week. Worst hit was Padang which saw a magnitude 7.6 earthquake yesterday followed by a second tremor. Within 24 hours the death toll was already standing at over 460 people.
The epicentre of the earthquake lay 140 miles to the southeast of Padang, the result of fault action between the Australian and Sunda tectonic plates. The Pacific Ring of Fire is a horseshoe shaped zone around the Pacific basin which is the meeting zone of different tectonic plates. Three quarters of the world's volcanoes are situated here and earthquakes are a common occurrence where one tectonic plate collides and is thrust below another plate.
1797 saw the last major earthquake like this for Padang. A magnitude 8.4 quake was experienced 350 kilometres to the south in September 2007, while a magnitude 8.7 quake shook the earth 300 kilometres to the north in March 2005. An earthquake which resulted in the Boxing Day tsunami of 2004 measured a magnitude of between 9.1 and 9.3, was one of the most violent earthquakes along this same sunda tectonic plate.
The South Pacific suffered the aftermath of a deep undersea earthquake on Tuesday, with a tsunami pelting the coastlines of Samoa, American Samoa and Tonga with very little warning. The magnitude 8 quake struck so close to land that there was no time for tsunami warning systems to prepare islanders for their fate. The tsunami struck the shore so quickly as a series of four waves that has caused widespread chaos and destruction.