India's only active volcano, located on Barren Island in the Andaman and Nicobar Islands, has erupted twice within a week, on September 13 and September 20, stirring interest and scientific scrutiny. The eruptions, considered minor, followed a magnitude 4.2 earthquake in the region on September 18. The Indian Navy recorded the event, showing red-hot lava flowing down the slopes and thick smoke emerging from the summit.
Barren Island is part of the Andaman and Nicobar Islands, situated approximately 140 km from Port Blair. The island is uninhabited, posing no immediate threat to human settlements. However, access to the island is restricted to protect its fragile ecosystem.
The recent volcanic activity is attributed to the region's geology, specifically the dynamics between the Indo-Australian and Eurasian (Sunda) tectonic plates. The Andaman-Nicobar arc is a subduction zone where the Indian plate slips beneath the Sunda plate into the mantle, triggering earthquakes and creating pathways for magma to rise. This process makes the region seismically and volcanically active.
Experts from the National Centre for Seismology suggest that the earthquake likely disturbed the volcano's magma chamber, located 18-20 kilometers beneath the surface. This disturbance, described as "earthquake shaking intensity," may have triggered a "premature magmatic eruption". O P Mishra, director of the National Centre for Seismology, noted that the fault's coordinates align with the latitude of the Barren Island volcano and lie close to the quake's longitude, conditions that made the magma chamber prone to eruption.
The Barren Island volcano's first recorded eruption dates back to 1787. After remaining dormant for nearly 150 years, it reawakened in 1991. Since then, eruptions have been recorded in 2005, 2017 and 2022. The 2004 Indian Ocean earthquake is considered to be linked to eruptions that occurred between 2005 and 2007.
Barren Island is roughly 3.2 km wide, rising almost 2 km above the surrounding seabed, with its main summit approximately 300-354 meters above sea level. The island's geology consists of a stratovolcano with pyroclastic cones. The oldest subaerial lava flows are estimated to be 1.6 million years old, with the volcano situated on oceanic crust approximately 106 million years old.
The Geological Survey of India (GSI) and the National Centre for Seismology are closely monitoring the island through satellite surveillance. They are analyzing data and new imagery to assess the eruption's scale and potential risks. The Indian Navy has also issued warnings to vessels to avoid the area.
