Volcanoes of India

S Balakrishnan *

Volcanoes in India! Yes, not just one but two - a sleeping (dormant) one and an active one. Both of them are isolated standalone volcanic islands situated in Andaman Sea (Bay of Bengal), falling within the Union Territory of Andaman & Nicobar Islands.

Volcanoes are classified as active, dormant and extinct. An extinct volcano is one that has no supply of magma (molten rock). Dormant volcanoes may remain sleepy even for thousands of years and then erupt suddenly. Don’t ‘under’estimate them!

To be on the safer side, let us first visit the dormant volcanic island ‘Narcondam’. The name is a derivative of Tamil ‘naraka’ (hell) ‘gundam’ (opening/hole/cauldron), obviously indicating the volcanic nature of the island. But whether the Tamils actually meant this island or the other one, the Barren Island, is not clear, but the name stuck to this volcanic island.

This small oceanic island of volcanic origin is 6.8 sq. km.; it is the easternmost island in the Andaman & Nicobar Group. The peak rises 710 meters above sea level. Narcondam is 240 km north-east of Port Blair, the capital town of the Union Territory, and is so isolated that it is 74 km (46 mi) to the east of the nearest North Andaman Island.

It is naturally cut off from any nearby landmass and thus stands majestically aloof and high. An unmanned lighthouse has been established on the slopes of Narcondam in 1983, powered by battery & solar panel. It is visited by the personnel of Lighthouse Department in their vessel which is anchored 4 kms off the shore; they then take a country boat (dinghy) to reach the shore and then walk to the lighthouse through dense forest and hilly terrain.

Narcondam is unique for the occurrence of the endemic Narcondam Hornbill (Aceros narcondami) which is found only in Narcondam Island, hence endemic. Population of the Narcondam hornbill is estimated to be around 50 to 250 individual birds. It feeds on berries and fruits in tall trees.

The species is recognised as endangered in the IUCN Red List and is protected under Schedule I of the Wild Life Protection Act of India granting it the highest level of protection in Indian Laws. The volcanic Narcondam island is a dormant inner arc volcano of the active Andaman–Java Subduction Complex in the Andaman Sea, and an outstanding example representing major stages of earth's history with significant geomorphic features.

Aerial view of Barren erupting

Besides, Narcondam is also an outstanding example of ongoing ecological and evolutionary processes. The lonely volcanic island is uninhabited except for a security post and, therefore, is naturally safeguarded.

The property has also been notified as Sanctuary under the provisions of the Wildlife (Protection) Act of 1972, granting it further protection. For these unique features, Narcondam volcanic island has been proposed for inclusion in UNESCO’s World Heritage Site list. Narcondam last erupted in 1681.

Now let us boldly visit the only active volcano of India, the Barren Island. It is so called because its slope is so barren, devoid of any vegetation. This is also an isolated volcanic island which is related to subduction of Indian plate beneath the overriding South-East Asian plate.

About sixty such potentially active volcanoes lie along the S-E Asian volcanic rim -1. Barren Island volcano (120 17’ N: 930 51’ E), covering an area of approximately 10 sq km, is also located in Andaman Sea. It is 135 Km N-E of Port Blair, i.e., 100 kms closer to Port Blair compared to Narcondam Island. Its height is 354 meters.

The eruption of Barren Island has been grouped into three time periods – pre-1787 (pre-historic), 1787-1832, and 1991-2015. Again, 1991-2015 period is further sub-divided into three periods – 1991, 1994-95 and 2005-2015. It has ejected lava and pyroclastic materials, thus creating a cinder cone of 305 m height with a 60m diameter crater during 1787-1832 period. This crater became 400 m wide and 200m deep in 1991.

If you are rich enough to charter a ferry, you can as well visit Barren Island with prior permission of Forest Department of A&N Administration. Foreigners, however, are not allowed to land on Barren Island; they can view the volcanic island from onboard only.

For those who cannot afford to charter a ferry, mud volcanoes of Baratang Island in Middle Andaman Island Group and near Diglipur in North Andaman are the poor man’s choice. As these two volcanic islands are out of reach of ordinary citizens (aam aadmi), I never had a chance to visit them during my living there (1978-1980).

As a humble citizen I could only visit the humble mud volcano of Baratang Island in 2009, during my revisit to the Islands. Some consolation! However, I could buy a video cassette in Port Blair that showcases the splendid eruption of Barren Island in 2005. I hope the Narcondam - remember, it is only dormant, not extinct - also displays its pyrotechnics before I depart from this world.