Macquarie Island - John Seach


Southern Ocean
Tasmania, Australia

54.50 S, 158.95 E
summit elevation 433 m

Macquarie Island is a Tasmanian State Reserve managed by the Tasmanian Parks and Wildlife Service. Australia.

It is a site of major geoconservation significance, being the only place on earth where rocks from the earth's mantle (6 km below the ocean floor) are being actively exposed above sea-level. Macquarie Island is a World Heritage listed site.

Captain Frederick Hasselborough of the brig Perseverance who sighted the island on 11 July 1810. He noted a wreck "of ancient design" on the island, possibly indicating Polynesian navigators had reached there before.

Australia's Sir Douglas Mawson established the island's first scientific station in 1911. Macquarie Island ANARE station was established on 25 March 1948 and has been operating continuously ever since.

Macquarie Island is on the Macquarie Ridge at the junction of the Pacific and Indo-Australian plates, 1500 km SE of Hobart, Tasmania. Large earthquakes (6 or greater on the Richter scale) occur approximately once a year.

Further Reading
Duncan, R.A. and Varne, R., 1988. The age and distribution of the igneous rocks of Macquarie Island. In Papers and Proceedings of the Royal Society of Tasmania (Vol. 122, No. 1, pp. 45-50).

Goscombe, B.D. and Everard, J.L., 1999. Macquarie Island mapping reveals three tectonic phases. Eos, Transactions American Geophysical Union80(5), pp.50-55.

Varne, R., Brown, A.V. and Falloon, T., 2000. Macquarie Island: its geology, structural history, and the timing and tectonic setting of its N-MORB to E-MORB magmatism. Special Papers-Geological society of America, pp.301-320.

Kriwoken, L.K. and Holmes, N., 2007. Emerging Issues of Australia’s Sub-Antarctic Islands: Macquarie Island and Heard Island and McDonald Islands. Looking South: Australia’s Antarctic Agenda, pp.149-64.

Macquarie Island Eruptions

10 million years ago.
Undersea eruptions ceased then island was uplifted in the past 600 to 700 thousand years.