Chile a seismic hot spot: expert
Chile covers an area where two tectonic plates meet and which sees some of the greatest seismic activity anywhere in the world, with a 8.0 quake every decade or so, a Paris-based expert said.world Updated: Feb 27, 2010 21:50 IST
Chile covers an area where two tectonic plates meet and which sees some of the greatest seismic activity anywhere in the world, with a 8.0 quake every decade or so, a Paris-based expert said.
"Chile is a unique natural laboratory to study earthquakes, since the speed of plate movements is very significant," said Chilean tectonic specialist Rolando Armijo of the Paris Institute of Earth Physics.
"The subduction zones are the most exposed regions of the world to seismic risks and tsunamis," Armijo said, describing a geological process in which one tectonic plate moves under another.
The massive 8.8-magnitude earthquake that rocked Chile early Saturday has killed at least 82 people, toppled buildings and triggered a tsunami threatening the Pacific rim of fire.
But it is not the biggest earthquake the country has witnessed. The world's largest-ever registered tremor, the 9.5-magnitude Valdiva quake, shook Chile in 1960.
That giant convulsion tore apart more than 1,000 kilometres (620 miles) of contact between two tectonic plates, the Nazca plate in the eastern Pacific basin and the South American plate
It also unleashed a tsunami which wrought destruction across the Pacific region.
Indeed, over the past century every seaside town in the South American nation has been affected by a significant quake. The country also has a long history of related tsunamis, documented back to the 16th century.
"In a region like Chile we know that an earthquake will take place but it's very difficult to make short-term predictions," Armijo said of this latest trembler. "We are going to do an 'autopsy' of this quake and determine whether there were early warning signs."
Chile's intense seismic activity has also produced the Andes mountain range, among other formations, he added.
"The centre of Chile in particular is a very sensitive area," Armijo said.
Other big subduction zones are located in Japan, North America and Indonesia.