The Islands: Andaman and Nicobar, and Lakshadweep

Detail

1. Two island groups: the big picture

• India has two island groups:
• Andaman and Nicobar Islands in the Bay of Bengal (east).

• Lakshadweep Islands in the Arabian Sea (west).

• They differ in where they came from:

• The Andamans and Nicobars are tectonic. They are mountain tops pushed up by moving plates.
• Lakshadweep is biological. It is built by tiny sea animals called corals.

2. Andaman and Nicobar Islands: location and extent

• Number: about 572 islands and islets. An islet is a very small island.
• Location: Bay of Bengal, at 6°–14°N and 92°–94°E.
• Two parts:
• Andaman group in the north: North, Middle and South Andaman, Little Andaman, and others.

• Nicobar group in the south: Car Nicobar, Little Nicobar, Great Nicobar, and others.

• Islet groups: the two main ones are Ritchie's archipelago and the Labyrinth islands.

• An archipelago is a cluster of islands close together.

• Both lie near the Andaman group.

• Neighbours: the islands lie closer to Myanmar (north) and Indonesia (Sumatra, south) than to the Indian mainland.

3. Origin: raised tops of an undersea mountain chain

• What they are: the islands are the elevated parts of submarine mountains. "Submarine" means under the sea.
• Link to the mainland mountains: this undersea chain continues the Arakan Yoma of Myanmar. The Arakan Yoma is the southern extension of the Purvanchal and Himalayan system. So the Andamans are a drowned branch of the same mountain-building that raised the Himalayas.
• How they formed (cause → process → result):
• Cause: the Indo-Australian plate and the south-eastern Eurasian plate keep pushing into each other [5].
• Process: the Indian side slides under the plate to its east. Sea-floor rock and mud are crumpled and pushed up into a long north–south ridge.

• Result: the highest parts of the ridge rise above the sea as the Andaman and Nicobar islands.

• Volcanic islands: some smaller islands are volcanic. They lie in a volcanic arc east of the main chain. A volcanic arc is a curved line of volcanoes that forms where one plate sinks under another.

• Earthquake risk: the area sits on the fault whose movement caused the 26 December 2004 tsunami [5]. A fault is a crack in the crust where blocks of rock move.

4. Volcanoes: Barren Island and Narcondam

• Barren Island is India's only active volcano.
• Location: about 135 km north-east of Port Blair, in the Andaman Sea [4].
• Type: a stratovolcano [5]. This is a steep, cone-shaped volcano built of layers of lava, rock pieces and volcanic ash.
• Size:
  • The island is only about 3 km wide [4].
  • It has a 2 km-wide caldera on its western side [4][5]. A caldera is a large bowl-shaped hollow left when a volcano blows out or collapses. This one formed in an explosive eruption in the Pleistocene (the Ice Age period, about 2.6 million to 12,000 years ago) [5].
• Height: it stands 354 m above sea level. Measured from the sea floor, it rises about 2,250 m [4]. So most of the volcano is hidden under water.

• Activity: it is the only historically active volcano in the north–south volcanic arc between Sumatra and Myanmar [4]. Recent eruptions:

  • 24 August 2005: smoke drifted east over the Andaman Sea [5].
  • 5 April 2006: an ash and steam plume [4].

• Narcondam Island is dormant. A dormant volcano is "sleeping": it has not erupted in recorded history but could erupt again. It lies north-east of Barren Island, in the same volcanic arc.

5. Channels and passages (north to south)

A channel is a stretch of sea between two land masses.

Channel	Lies between	Notes
Duncan Passage	South Andaman and Little Andaman	Inside the Andaman group
Ten Degree Channel	Little Andaman and Car Nicobar	About 150 km wide, along 10°N. Separates the Andaman group from the Nicobar group
Six Degree Channel	Great Nicobar and Sumatra (Indonesia)	Along about 6°N. Links the Bay of Bengal and Andaman Sea with the Strait of Malacca route

• Exam trap: the Ten Degree Channel is in the Bay of Bengal. The Nine Degree and Eight Degree channels are in the Arabian Sea (Lakshadweep).

6. Peaks of the Andaman and Nicobar Islands

Peak	Island	Height
Saddle Peak	North Andaman	738 m (highest)
Mount Thuiller	Great Nicobar	642 m
Mount Diavolo	Middle Andaman	515 m
Mount Koyob	South Andaman	460 m

• Order from highest to lowest: Saddle Peak → Thuiller → Diavolo → Koyob.
• North to south by island: Saddle (North Andaman) → Diavolo (Middle Andaman) → Koyob (South Andaman) → Thuiller (Great Nicobar).
• Barren Island (354 m above sea) [4] is lower than all four peaks.

7. Climate, vegetation and coasts of the Andamans and Nicobars

• Convectional rain: rain caused by hot air rising.
• The sun heats the land and sea strongly every day.
• Warm, moist air rises and cools.
• Its water vapour condenses into clouds.

• Rain falls, often in the afternoon, almost every day.

• Why it happens here: the islands lie close to the equator (6°–14°N) and are surrounded by warm sea.

• Vegetation: equatorial forest, which is dense, evergreen and many-layered. More than 75% of the islands' area is under forest [2].
• Coasts: the islands have coral deposits and fine beaches.

8. History and strategic role

• "Outposts" of India: the islands guard India's eastern sea approaches. The Indian Navy has a presence there.
• Cellular Jail at Port Blair: the British held Indian freedom fighters here.
• Sea routes: Great Nicobar is only about 40 nautical miles from the main East–West international shipping route [2]. A nautical mile is about 1.85 km.

9. Lakshadweep Islands: location and extent

• Location: Arabian Sea, at 8°–12°N and 71°–74°E. They lie 220–440 km off the Kerala coast.
• Number: about 36 islands (Britannica: "some three dozen").
• Area:
• Total land area is only about 32 sq km. This makes Lakshadweep India's smallest Union Territory [6].

• The islands are scattered over about 78,000 sq km of sea [6].

• People:

• 10 islands are inhabited [7] (NCERT: 11).

• Most people live on four islands: Andrott, Kavaratti, Minicoy and Amini [7].

• Capital: Kavaratti.

10. Origin: coral islands

• Coral: a tiny sea animal (the coral polyp). It builds a hard skeleton of calcium carbonate (lime).
• Coral reef: a ridge made of millions of these skeletons. Corals need warm (about 20°C or more), clear, shallow, salty water. That is why they grow in tropical seas like the Arabian Sea.
• Atoll: a ring-shaped coral reef or island around a lagoon. A lagoon is a shallow body of sea water cut off by the reef.

• Almost every inhabited Lakshadweep island is a coral atoll [7].

• How an atoll forms (cause → process → result):

• Cause: coral reefs grow around a volcanic island or a raised part of the sea floor.
• Process: the base slowly sinks, but the corals keep growing upward towards sunlight.

• Result: a ring of coral is left around a central lagoon. Waves pile up broken coral sand on the ring, and low, flat islands form.

• Same type elsewhere: the Maldives, to the south, is also made of coral atolls.

11. Physical features of Lakshadweep

• Relief: the islands are flat and low, only a few metres above the sea.
• Storm beaches line the eastern seaboard.
• A storm beach is a bank of loose (unconsolidated) pebbles, shingle, cobbles and boulders. "Unconsolidated" means not stuck together into rock.

• Strong storm waves throw this material high up the shore.

• Cover: coconut palms and sandy beaches. There is no dense forest.

12. Lakshadweep channels and island groups (north to south)

• Amindivi (Amini) islands are the northern group.
• The Nine Degree Channel runs along about 9°N:
• The Amindivi islands lie north of the line between them and the Cannanore islands.
• The Cannanore islands lie to the south.

• Minicoy lies south of the channel.

• The Eight Degree Channel runs along about 8°N. It separates Minicoy (India) from the Maldives.

13. Minicoy Island and the "largest island" error

• Minicoy is the southernmost island of Lakshadweep, next to the Eight Degree Channel.
• NCERT error: NCERT calls Minicoy the largest island, "with an area of 453 sq km". This cannot be true, because all of Lakshadweep together has only about 32 sq km of land [6].
• Correct facts:
• Andrott (about 4.9 sq km) is the largest island.
• Minicoy (about 4.4 sq km) is the second largest.

14. Comparison: Bay of Bengal islands vs Arabian Sea islands

Feature	Andaman and Nicobar (Bay of Bengal)	Lakshadweep (Arabian Sea)
Number	~572	~36
Latitude and longitude	6°–14°N, 92°–94°E	8°–12°N, 71°–74°E
Origin	Tectonic (raised undersea mountains continuing the Arakan Yoma); some volcanic	Coral (atolls)
Relief	Hilly; highest point Saddle Peak, 738 m	Flat, low-lying
Size	Large islands	Tiny; total land about 32 sq km [6]
Cover	Dense equatorial forest	Coconut palms, beaches
Volcanoes	Barren Island (active), Narcondam (dormant)	None
Channels	Duncan Passage, Ten Degree, Six Degree	Nine Degree, Eight Degree
Closest foreign neighbours	Myanmar, Indonesia	Maldives
Capital	Port Blair	Kavaratti

15. Great Nicobar Island Development Project

• What it is: a large plan to build up Great Nicobar, India's southernmost island. It was taken up from 2021 and is estimated to cost about ₹72,000 crore.
• Parts of the project (as of May 2026) [2]:
• An International Container Transhipment Terminal (ICTT) at Galathea Bay, with a capacity of 14.2 million TEU. A TEU (twenty-foot equivalent unit) is the size of one standard 20-foot shipping container. "Transhipment" means moving cargo from one ship to another on the way to its final port.
• A greenfield international airport, built on new land, handling 4,000 peak hour passengers.
• A 450 MVA gas and solar power plant.

• A township spread over 16,610 hectares.

• Why Galathea Bay:

• It is about 40 nautical miles from the East–West shipping route.
• The water there is naturally more than 20 m deep [2][3].

• Today, Indian cargo is transhipped at Colombo, Singapore and Klang. The new port aims to reduce this dependence [2].

• Port cost and timeline (November 2023):

• The port alone was estimated at about ₹44,000 crore.

• Phase 1 was planned to open in 2028 with about 4 million TEU, growing to 16 million TEU by 2058 [3].

• Clearances:

• The Ministry of Environment, Forest and Climate Change gave environmental clearance on 11 November 2022, and Stage-1 forest clearance was also granted [3].

• The clearance carries 42 conditions [2].

• Phases and area (as of May 2026) [2]:

• Phase I: 2025–35, 72.12 sq km.
• Phase II: 2036–41, 45.27 sq km.
• Phase III: 2042–47, 48.71 sq km.

• Total: 166.10 sq km. Of this, 130.75 sq km is forest land.

• Concerns and official data:

• Forests:
  • The project diverts 1.82% of the islands' forest cover.
  • About 18.65 lakh trees stand in the area, and up to 7.11 lakh may be cut.
  • Compensatory afforestation (planting new forest to make up for forest lost) is planned over 97.30 sq km in Haryana, far from the island [2].
• Leatherback turtle: Galathea Bay's beaches are a nesting site for the leatherback turtle, the largest sea turtle.
• Tribal peoples:
  • About 237 Shompen live on the island. They are hunter-gatherers and a PVTG (Particularly Vulnerable Tribal Group).
  • About 1,094 Nicobarese also live there. They are coastal fishing people.
  • Of the project area, 84.10 sq km overlaps the tribal reserve. The government says no one will be displaced, and that re-notification (officially marking new land as reserve) will add 3.912 sq km to the reserve overall [2].

• Earthquakes and disasters: the island lies in a seismically sensitive and cyclone-prone zone [2], close to the fault behind the 2004 tsunami [5].

• Status: cleared and moving ahead in phases (official position, May 2026) [2]. Check for later changes before writing about it.

Prelims Hooks

• India's only active volcano: Barren Island (Andaman Sea), a stratovolcano about 135 km north-east of Port Blair [4][5]. Narcondam is dormant.
• Ten Degree Channel separates Little Andaman from Car Nicobar. Duncan Passage separates South Andaman from Little Andaman. Six Degree Channel separates Great Nicobar from Sumatra.
• Nine Degree Channel separates the Amindivi and Cannanore islands from Minicoy. Eight Degree Channel separates Minicoy from the Maldives.
• Peaks, highest to lowest: Saddle Peak (North Andaman, 738 m) > Mount Thuiller (Great Nicobar, 642 m) > Mount Diavolo (Middle Andaman, 515 m) > Mount Koyob (South Andaman, 460 m).
• Andaman and Nicobar origin: submarine mountains continuing the Arakan Yoma (tectonic). Lakshadweep origin: coral atolls.
• Largest Lakshadweep island: Andrott, not Minicoy. Minicoy is the southernmost and second largest. Total land is only about 32 sq km, the smallest UT [6].
• Storm beaches (loose pebbles, shingle, cobbles and boulders) lie on the eastern seaboard of Lakshadweep.
• Galathea Bay (Great Nicobar) is the site of the planned transhipment port, about 40 nautical miles from the East–West shipping route [2].
• Capitals: Port Blair (Andaman and Nicobar), Kavaratti (Lakshadweep).

Mains Points

• Contrast in origin shapes everything else (GS-I):
• The Andamans and Nicobars are raised tops of a plate-boundary mountain chain. So they are hilly, large, forested, volcanic in places, and prone to earthquakes and tsunamis (2004).

• Lakshadweep is made of coral. So it is flat, tiny, low-lying, and very exposed to sea-level rise and coral bleaching.

• Strategic value (GS-I/III):

• The Andamans and Nicobars sit near the Six Degree Channel and the Malacca route, about 40 nautical miles from the East–West shipping lane [2].
• Lakshadweep guards the Eight and Nine Degree channels on Arabian Sea trade routes.

• Both groups extend India's Exclusive Economic Zone and naval reach.

• Development vs ecology on Great Nicobar (GS-III):

• Gains: a deep-water transhipment port (more than 20 m deep), less dependence on Colombo and Singapore, and a stronger defence presence [2].
• Costs: loss of forest (1.82% of the islands' forest; up to 7.11 lakh trees), afforestation done far away in Haryana, risk to leatherback nesting beaches and the Shompen (a PVTG), and seismic and tsunami risk [2].

• Way forward: independent monitoring committees, phased tree felling, and disaster-resilient design [2].

• Island fragility (GS-III, disasters):

• Lakshadweep's low coral islands have very little land (about 32 sq km) [6] and depend on reefs and storm beaches for protection.
• Reef health, freshwater lenses and coastal regulation are key to adapting to climate change.