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Heard Island and McDonald Islands

Photos of Heard Island and McDonald Islands

The northeastern slopes of Big Ben volcano on Heard Island are visible in shadow at the top right of this photo. Mawson Peak (small circle in the upper center of the image), sits within a breached caldera (collapsed and empty magma chamber beneath a volcano) on the southwestern side of the volcano - the shadow cast by Mawson Peak points directly to the crescent-shaped caldera rim.  This image, taken during the Southern Hemisphere summer, also shows the dark brown volcanic rock that forms the island. The southwest-pointing tongue of ice is Gotley Glacier. Image credit: NASA.



American sailor John HEARD discovered Heard Island in 1853 while fellow American William MCDONALD discovered the McDonald Islands the following year. Starting in 1855, sealers lived on the islands and harvested elephant seal oil; by the time the practice was ended in 1877, most of the islands’ seals were killed. The UK formally claimed the islands in 1910, and Australian explorer Douglas MAWSON visited Heard Island in 1929. In 1947, the UK transferred the islands to Australia for its Antarctica research, but Australia closed the research station on Heard Island in 1954 when it opened a new research station on the Antarctic continent. McDonald Island has been an active volcano since it emerged from dormancy in 1992, and the island doubled in size after an eruption in 1996. In 1997, the islands were named a UNESCO World Heritage site. Populated by a large number of bird species, seals, and penguins, the islands are primarily used for research, with limited fishing permitted in the surrounding waters.


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islands in the Indian Ocean, about two-thirds of the way from Madagascar to Antarctica

Geographic coordinates

53 06 S, 72 31 E

Map references

Antarctic Region


total: 412 sq km

land: 412 sq km

water: 0 sq km

comparison ranking: total 202

Area - comparative

slightly more than two times the size of Washington, DC

Land boundaries

total: 0 km


101.9 km

Maritime claims

territorial sea: 12 nm

exclusive fishing zone: 200 nm




Heard Island - 80% ice-covered, bleak and mountainous, dominated by a large massif (Big Ben) and an active volcano (Mawson Peak); McDonald Islands - small and rocky


highest point: Mawson Peak on Big Ben volcano 2,745 m

lowest point: Indian Ocean 0 m

Land use

agricultural land: 0% (2011 est.)

other: 100% (2018 est.)

Natural hazards

Mawson Peak, an active volcano, is on Heard Island

Geography - note

Mawson Peak on Heard Island is the highest Australian mountain (at 2,745 meters, it is taller than Mt. Kosciuszko in Australia proper), and one of only two active volcanoes located in Australian territory, the other being McDonald Island; in 1992, McDonald Island broke its dormancy and began erupting; it has erupted several times since, most recently in 2005

People and Society


total: uninhabited


Environment - current issues

none; uninhabited and mostly ice covered



Land use

agricultural land: 0% (2011 est.)

other: 100% (2018 est.)


Country name

conventional long form: Territory of Heard Island and McDonald Islands

conventional short form: Heard Island and McDonald Islands

abbreviation: HIMI

etymology: named after American Captain John HEARD, who sighted the island on 25 November 1853, and American Captain William McDONALD, who discovered the islands on 4 January 1854

Dependency status

territory of Australia; administered from Canberra by the Department of Agriculture, Water and the Environment (Australian Antarctic Division)

Legal system

the laws of Australia apply where applicable

Diplomatic representation in the US

none (territory of Australia)

Diplomatic representation from the US

embassy: none (territory of Australia)

Flag description

the flag of Australia is used

National heritage

total World Heritage Sites: 1 (natural); note - excerpted from the Australia entry

selected World Heritage Site locales: Heard Island and McDonald Islands




2 (2024)

Military and Security

Military - note

defense is the responsibility of Australia; Australia conducts fisheries patrols

Transnational Issues