Barren Island, the only active volcano in India, is situated in the Andaman Islands. Let's explore the details behind this answer.

The Andaman Islands:
The Andaman Islands are a group of islands located in the Bay of Bengal, specifically in the southeastern part of the Indian subcontinent. These islands are an archipelago of over 572 islands, which are divided into two main groups - the Andaman Islands and the Nicobar Islands.

Barren Island:
Barren Island is a small island located in the Andaman Sea. It is a part of the Andaman Islands group and is known for being the only active volcano in India. The island is situated approximately 138 kilometers northeast of Port Blair, the capital city of the Andaman and Nicobar Islands.

Active Volcano:
Barren Island is renowned for its active volcano, which has been sporadically erupting since its first recorded eruption in 1787. The volcano is classified as a stratovolcano, which means it is composed of layers of hardened ash, lava, and volcanic debris. The volcanic activity at Barren Island is closely monitored by the Geological Survey of India and other scientific organizations.

Recent Eruptions:
In recent years, Barren Island has witnessed several eruptions. The most notable eruptions occurred in 1991, 1994-95, 2005-07, and 2010-11. These eruptions have led to the formation of new lava flows, volcanic cones, and ash deposits on the island. The volcano emits gases such as sulfur dioxide, carbon dioxide, and hydrogen sulfide, making the area hazardous for human habitation.

Biodiversity:
Despite the volcanic activity, Barren Island supports a unique ecosystem. The island is home to a diverse range of flora and fauna, including coral reefs, mangroves, and various species of birds. However, the volcanic eruptions and the resulting ashfall have significantly impacted the surrounding marine life, leading to a decline in coral cover and fish populations.

In conclusion, Barren Island, the only active volcano in India, is situated in the Andaman Islands. Its volcanic activity and unique biodiversity make it an important area of study for scientists and researchers.