India's only active volcano, located on Barren Island in the Andaman Sea, experienced an earthquake-triggered eruption on September 20, 2025. According to seismology expert O P Mishra, the eruption was a result of a 4.2-magnitude earthquake in the region.
Barren Island, part of the Andaman and Nicobar Islands, lies approximately 138 km northeast of Port Blair. The island itself spans roughly 3 sq km and is characterized by volcanic cones and ash. Rising 354 meters above sea level, it is a striking geological feature.
The eruptions on September 13 and September 20 were both classified as minor, posing no immediate threat to nearby areas. While these events have garnered attention, officials have stated that there is no cause for alarm, and that monitoring of the island continues.
Barren Island has a recorded history of eruptions dating back to 1787. Since then, it has experienced several episodes of activity, with significant eruptions occurring in 2017 and 2022. The most recent activity prior to September 2025 was in July 2025. The island is under constant observation by the Indian National Centre for Ocean Information Services (INCOIS) and other agencies to track seismic and volcanic activity.
The recent activity went viral after social media users shared visuals of smoke and minor lava emissions. Experts have noted that such eruptions are not unusual, given the island's history of intermittent volcanic activity.
Although uninhabited due to its terrain and volcanic nature, Barren Island is a popular attraction for scuba divers and adventure tourists, who are permitted to visit nearby waters under controlled conditions. Authorities emphasize that safety protocols are in place, with tourist access restricted to avoid any risk.
The geological composition of Barren Island is noteworthy. Argon-argon dating of samples has established that the oldest subaerial lava flows are 1.6 million years old, and the volcano is located on an oceanic crust approximately 106 million years old. All recorded eruptions fall on the low end of the Volcanic Explosivity Index. For example, the 2017 eruption was recorded as a 2 on the index.
In the past, eruptions have had an impact on the island's biodiversity. A 1993 study assessing the impact of eruptions on animal species found a reduction in bird species and their population. However, continuous monitoring helps track any escalation in volcanic behavior, ensuring safety and preparedness.
