Thursday, June 2 2005 10:40 Hrs (IST) - World Time -

Port Blair: Incessant monsoon rains cooled off the lava-spewing Barren Island volcano two days after it erupted on May 28 but the occurrence coming a decade after its last such fury would result in a new map for the uninhabited land nestled in the Indian Ocean.

A slew of post-monsoon scientific expeditions are being planned to take a peek at India's only live volcano and one of them would track the topographical changes that have taken place due to fresh lava deposits on the Island.

"There has been a lot of fresh deposit on the surface of the Island after the volcanic eruption. We will try to find out the chemical composition of this material and make a new map for Barren Islands," Prof D Chandrasekharam, head of Indian Institute of Technology (IIT) Mumbai's Centre for Studies in Resources Engineering, told sources.

Chandrasekharam, who led the first ever scientific expedition to the Island in February 2003 and had indicated that the volcano would erupt sometime after the December 26 tsunami, said that a "swarm" of earthquakes of similar intensities had resulted in severe tectonic movement and underground friction.

"It is a well known fact now that the India plate has gone down the Sumatra plate. This resulted in friction and that explains the current volcanic activity," he said.

The Barren Island volcano had erupted once in 1994 and showed a little activity again in 2000. The last map of the Island had been released at a meet in Florence after the Indo-Italian expedition of 2004.

Coast Guard DIG S P S Basra, an eyewitness to the volcanic eruption, said Geological Survey of India (GSI) scientists had not been able to reach the Island immediately after the event due to heavy rains.

"We have, however, received a request from the GSI to collect lava samples for them," said Basra, who, along with four other military and para-military personnel was the first to step on the Island after the volcano erupted.

The Island is out of bounds and accessible only by the Coast Guard.

In Kolkata, GSI Deputy Director General M K Mukhopadhyay said the re-adjustment of lithospheric plates and its consequent effects on the volcanic activity would be one of the major areas of research.

The earthquake swarms in Andaman and Nicobar Islands started immediately after the Sumatra earthquake on December 26 and over 200 tremors were experienced till January 25, 2005, according to a recent report by the United States Geological Survey (USGS).

The earthquakes occurred on the eastern boundary of the Burma (Myanmar) plate with Sunda plate - the zone of 'strike slip' (lateral movement) and normal faulting.

In the swarms that occurred after January 26, the largest magnitude observed was 5.8 and there were a large number of earthquakes with magnitude between 5 and 5.8, Chandrasekharam said.

The Andaman and Nicobar Islands are situated on an undersea fault that continues to Indonesia to the south.

Andaman authorities said there was no immediate threat to the environment and marine life in the Islands after the volcano spewed molten rocks and gas upto 90 feet.

Basra said his team saw red hot flames shooting out every few seconds and could not go beyond 50 metres of the coastline into the Island.

"Fresh sorties have been inspecting the crater and found out that there could be more than one vents of the volcano from which the lava and smoke came out," he added.