The entirety of the island measures approximately 11 miles (18 km) by 5 miles (8 km), covers 156 sq km and is located 250 miles (400 km) off the Antarctic coast (northeast of the Eights Coast of Ellsworth Land).
The island is thougt to be an extinct volcano with steep slopes, attaining a peak height of 1755 meters above sea level in Lars Christensen Peak with a flat summit area (100 meters wide) indicates the presence of a summit crater.
At least 95% of the island is covered by permanent ice and snow and the island is surrounded by pack ice during most of the year which extends all the way to the Antarctic coast. In the summer, three small rocky beaches are exposed. Two ice-free, flat-topped columnar rocks, the Tvistein Pillars, lie just east of the steepest coast of the island. A high central piedmont plateau dominates the west, while gradual shelves of glacial ice characterize much of the north and south coasts.
This island was discovered in January 1821 by an expedition of exploration led by the Russian Thaddeus von Bellingshausen, who named it for Tzar Peter the Great. The first landing occured in 1929 by the second "Norvegia" expedition led by Ola Olstad, who claimed the island for Norway.
Since 1959, the island has been under the jurisdiction of the Antarctic Treaty System which recognizes neither permanent population nor citizenship or government in Antarctica; neither recognizes or disputes any territorial claims; emphasizes peaceful scientific activity; and limits military activity to support of such peaceful endeavors. The Antarctic Treaty System has been the umbrella for numerous agreements aimed at protecting the flora and fauna, natural resources and the natural environment of Antarctica.
- Geographic Names Information Service, United States Geological Survey] retrieved November 30, 2008
- Peter I Island Expedition
- Volcano Live
- Volcanos of the World, Smithsonian Institute
- The complete Guide to Antarctic Wildlife", Hadoram Shirihai & Brett Jarrett, 2002,
- Antarctic Odyssey, Graham Collier & Patricia Graham Collier, 1999.