India’s only live volcano in the Andaman and Nicobar Islands has started spewing smoke and lava again.
After lying dormant for 150 years, Barren Island volcano erupted in 1991 and has been showing sporadic activity since then, scientists of Goa-based National Institute of Oceanography (NIO) said.
“The volcano is erupting in small episodes of five to 10 minutes,” Abhay Mudholkar, who is heading an NIO team which is collecting samples in the Andaman basin, said on Friday.
“During the day, only ash clouds were observed. But after sundown, red lava foundations were spewing from the crater into the atmosphere and hot lava streamed down the slopes,” he said.
The site was later revisited by B Nagender Nath and his team and they too witnessed the continuation of spurts of blasts and smoke.
Researchers from Council of Scientific & Industrial Research (CSIR) and NIO have sampled sediments and water in the vicinity and recovered coal-like black pyroclastic material representing proximal volcanic ejecta.
These samples will help in deciphering the nature of present and past volcanic activity in the region.
“We are checking the composition of the lava and powdering the black sand to figure out the components,” Mudholkar said. The Andaman basin is an active back-arc spreading basin known for strong seismicity, submarine volcanoes and hydrothermal activity.
Scientists from CSIR-NIO have been surveying the basin and have identified several small submerged volcanoes in a linear chain called a volcanic arc.
“These volcanoes are formed due to the rising magma formed deep in the mantle due to the melting of the subducted Indian Ocean crust,” said Nath.
“A few of these submarine volcanoes have been dredged for samples and a pumice type of light volcanic rock has been recovered.”
The volcanic island is uninhabited and its northern part is, as the name suggests, barren and devoid of vegetation. Indian citizens can visit the island by chartered boats after obtaining permission from the forest department in Port Blair.