Volcanism comprises the planetary geodynamic process wherein subterranean molten rock (magma), volatiles, and pyroclastic ejecta ascend through crustal fractures to erupt upon the surface as lava. Volcanic eruptive dynamics are fundamentally governed by magma chemistry, specifically silica concentration and dissolved volatile fractions. Low-silica basaltic magmas possess low viscosity, permitting dissolved gases to vent gently and producing broad, gently sloping shield volcanoes such as Mauna Loa in Hawaii, as well as expansive flood basalt provinces like India's Deccan Traps. In contrast, intermediate-to-high silica andesitic and rhyolitic magmas exhibit high viscosity, trapping pressurized volcanic gases until explosive catastrophic eruptions occur. These explosive events construct steep-sided stratovolcanoes (composite cones) characterized by alternating strata of pyroclastics and viscous lava flows, exemplified by Mount Fuji, Mount Rainier, and Mount Vesuvius. The Pacific Ring of Fire, a 40,000-kilometer horseshoe-shaped belt coinciding with active subduction boundaries and oceanic trenches, hosts roughly seventy-five percent of Earth's subaerial volcanoes and ninety percent of global seismic shocks. Intrusive volcanic structures solidify below the surface as plutons, including massive granitic batholiths, concordant sills, and discordant dykes. India contains South Asia's only confirmed active volcano at Barren Island in the Andaman Sea, alongside the dormant volcanic landform of Narcondam Island.
High-yield conceptual summaries for competitive exams and rapid revision.
Magma is molten or semi-molten rock stored beneath Earth's crust, whereas lava is molten rock that breaches and flows upon the planetary surface.
Basaltic lava has low silica content (under 52 percent), low viscosity, high temperatures (1000°C–1200°C), and flows smoothly over great distances.
Rhyolitic and andesitic lavas contain high silica fractions (above 60 percent), making them highly viscous and susceptible to explosive gas discharge.
Shield volcanoes, such as Mauna Kea and Mauna Loa in Hawaii, feature broad, low-profile convex summits formed by successive layers of fluid basaltic lava.
Composite volcanoes (stratovolcanoes) have steep, symmetrical cones composed of alternating strata of hardened lava, tephra, pumice, and volcanic ash.
A caldera is a massive circular volcanic depression formed when a magma chamber empties rapidly during an eruption, causing the overlying volcanic cone to collapse.
Crater Lake in Oregon, USA, occupies a prominent caldera formed by the catastrophic collapse of Mount Mazama approximately 7,700 years ago.
The Pacific Ring of Fire (Circum-Pacific Belt) is a 40,000-km horseshoe-shaped zone of convergent tectonic plate boundaries containing over 450 active volcanoes.
Mount Stromboli in Italy is nicknamed the "Lighthouse of the Mediterranean" due to its nearly continuous, regular incandescent gas and scoria eruptions.
Barren Island, located in the Andaman Sea approximately 138 km northeast of Port Blair, is the only historically active volcano in South Asia.
Narcondam Island in the Andaman and Nicobar archipelago is classified as a dormant volcanic island of andesitic composition.
The Deccan Traps in west-central India represent a large igneous province of flood basalt erupted approximately 66 million years ago from the Reunion hotspot.
Batholiths are gigantic discordant plutonic igneous rock bodies with surface exposure exceeding 100 square kilometers, typically composed of granite or granodiorite.
Dykes are discordant, sheet-like intrusive igneous bodies that cut perpendicularly across pre-existing rock layers, whereas sills are concordant horizontal intrusions.
The Barren Island, containing the only confirmed active volcano in South Asia, is part of which island group?
Verified Explanation
Barren Island is an active stratovolcano situated in the Andaman Sea, approximately 135 km northeast of Port Blair.
2ID: GK-GEOG-00628
mediumPhysiography & Mountain Ranges
Barren Island, which hosts the only confirmed active volcano in the South Asian subcontinent, is located in which marine region?
Verified Explanation
Barren Island is an active stratovolcano situated in the Andaman Sea, about 138 km northeast of Port Blair in the Andaman and Nicobar Islands territory.
3ID: GK-DMGT-00531
easyEarthquakes, Seismic Zonation & Landslides
Which is the only active volcano in India, located in the Andaman Sea, whose seismic and eruptive activity is continuously tracked by GSI and NCS?
Verified Explanation
Barren Island, situated approximately 135 km northeast of Port Blair in the Andaman Sea, is the only confirmed active volcano in India and South Asia. Formed along the active subduction boundary where the Indian tectonic plate subducts beneath the Burma microplate, Barren Island erupted explosively in 1991 after nearly two centuries of dormancy, and has exhibited periodic strombolian eruptive activity and seismic swarms monitored by GSI, NCS, and INCOIS.
4ID: GK-STUT-00046
easyNortheast States & Island Territories
Which is the only active volcano in India (and South Asia), located in the Andaman Sea?
Verified Explanation
Barren Island, situated about 135 km east of Port Blair in the Andaman Sea, is the only confirmed active volcano in South Asia.
5ID: GK-STUT-00257
easyNortheast States & Island Territories
Which island in the Andaman Sea contains South Asia's only confirmed active volcano?
Verified Explanation
Barren Island, situated about 135 km northeast of Port Blair in the Andaman Sea, is the only confirmed active volcano in South Asia.
6ID: GK-STUT-00354
mediumNortheast States & Island Territories
Which island in the Andaman Sea hosts the only confirmed active volcano in South Asia and the Indian subcontinent?
Verified Explanation
Barren Island, located about 138 km northeast of Port Blair in the Andaman Sea, is the only active volcano along the volcanic arc between Sumatra and Myanmar.
7ID: GK-STUT-00407
easyNortheast States & Island Territories
Which island located in the Andaman Sea holds the distinction of being the only confirmed active volcano in India?
Verified Explanation
Barren Island, situated about 138 km northeast of Port Blair in the Andaman Sea, is India's only active volcano and the only active volcano along the chain from Sumatra to Myanmar.
8ID: GK-STUT-00533
mediumNortheast States & Island Territories
Which is the only active volcano located within Indian territory?
Verified Explanation
Barren Island, situated in the Andaman Sea about 135 km northeast of Port Blair, is the only confirmed active volcano in South Asia.
9ID: GK-RECD-00506
mediumWorld Superlatives Geo
What is the highest active volcano in the world, rising to an elevation of 6,893 meters (22,615 feet) on the international border between Chile and Argentina?
Verified Explanation
Ojos del Salado in the Andes mountains is the highest active volcano on Earth and the second-highest peak in the Western and Southern Hemispheres after Aconcagua.
10ID: GK-GEOG-00464
hardForests & Wildlife Sanctuaries
Which island in the Andaman and Nicobar archipelago houses the only active volcano in South Asia?
Verified Explanation
Barren Island, situated about 138 km northeast of Port Blair in the Andaman Sea, is the only confirmed active volcano in South Asia, with its latest eruptions recorded in recent decades.