Lord Howe Island Lagoon

October 23, 2003

Lordhowelagoon copy

Provided by: Roger Scott, Pine Rivers State High School
Summary authors & editors: Roger Scott

Lord Howe Island is the remnant of a volcano produced by submarine volcanic activity, which began erupting about 7 million years ago. Eruptions continued for about half a million years. Since then, this island has rafted on its tectonic plate -- it's now located north of the hot spot. Should it reactivate, a new volcano will be produced to the south of Lord Howe Island. Since activity ceased, erosion has considerably reduced the exposed igneous land mass. The main island is about 10 km in length and up to about 3 km wide. Topographically, the island is dominated by two peaks, Mt. Lidgbird (777 m, on the left) and Mt Gower (875 m). Both lie at the southern end of the island.

Although at a latitude of 31 degrees south (longitude of 159 degrees east), coral grows around Lord Howe Island. These corals are reputed to be the most southerly known. A fringing reef occurs on the western side of the island, forming the beautiful lagoon pictured above. See also the Earth Science Picture of the Day for August 7 and September 20 of this year.

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