If experts are to be believed, India has reasons to worry. They say the country should not be surprised if a major earthquake hits the Indian Ocean region in near future. Seismologists draw parallels to the quakes that hit the Pacific region, extending from Peru to Banda Sea in the east of Indonesian islands.
They say since January 13, 2007 till August 18, there were 16 major earthquakes measuring between 6.5 on the Richter scale to the recent Peru earthquake which measured 7.9 on the scale.
Scientific analysis shows that there were certain similarities between the tectonic setting of Peru and Sumatra. The Peru earthquake occurred along the boundary between the Nazca and South American tectonic plates and the mechanism was found similar to the Sumatra earthquake of December 2004. The region around Indonesia is very active, triggering several hundreds of earthquakes during the last one year.
Some of them occurred along the Andaman Nicobar Islands, Dr D Chandrasekharan, Department of Earth Sciences Department, Indian Institute of Technology, said.
"The Nazca and South American plates are converging at a rate of 77 mm per year while the Sumatra and Indo-Australian plates are moving at the rate of 60 mm per year. Both the earthquakes occurred due to thrust faulting," he said. Like Sumatra region, Peru experienced similar destructive earthquakes in the past, with a magnitude of 9.0 in 1868, 7.7 in 1942, 8.1 in 1974 and 7.7 in 1996. The 1868 earthquake generated a destructive tsunami that killed several thousands of people along the coast.
The August 15 Peru quake of 7.9 magnitude with almost 51 aftershocks generated a tsunami, but it was not as strong enough to destroy properties of the countries located along Eastern Pacific region including South and North America, Chandrasekharan said. While the similar earthquake in Peru during 1868 causing tsunami damaged even Hawaii islands that are situated several thousand kilometers away -- a phenomenon that India experienced on December 26, 2004 by the Sumatra earthquake, he said.
The scientist said the Pacific Tsunami Warning Centre within minutes after the occurrence of the Peru earthquake gave tsunami warning to all the countries along the Pacific coast. But, he added, "We are not sure about the Indian tsunami warning system." Chandrasekharan further said Alaska experienced maximum number of earthquakes within this period, with the occurrence of 6.5 magnitude earthquake just before the major Peru's 7.9 magnitude earthquake.
This belt experienced innumerable earthquakes of lesser magnitudes less than 6.5 in this period.
"This earthquake activity has triggered the Indonesian tectonic regime thereby triggering earthquakes with magnitudes up to 7.4 in Java (August 8 2007) and 6.2 in Banda Sea (August 17)," he added.
The Java earthquake was the largest one that occurred in the recent past with the Indonesian islands. This earthquake focus was deep and hence tsunami could not be generated. The scientist warned that India must be prepared for a major earthquake in the Indian Ocean region in the near future and the country's functional tsunami warning system should be in place soon.