Cockburn Island (Cockburn Island)
Cockburn Island is an oval island 2.7 km long, consisting of a high plateau with steep slopes surmounted on the northwest side by a pyramidal peak 450 m high, lying in the north-east entrance to Admiralty Sound, south of the north-east end of the Antarctic Peninsula. It was discovered by a British expedition (1839–43) led by Captain James Clark Ross, who named it for Admiral Sir George Cockburn, then serving as First Naval Lord (commander-in-chief of the Royal Navy).
Geologically, the area makes up the Cockburn Island Formation, which was studied extensively in the late 1990s by H. A. Jonkers. Rocks found on the island are volcanic, and the island is characterized by its "precipitous cliffs". A "Pecten conglomerate" from the late Pliocene or early Pleistocene period has been identified on the island, situated on a wave-cut platform at 720–820 ft. The island is a rare volcano type called a tuya, or moberg, which was formed by a three-stage eruption sequence below an ice cap. The first stage was a subglacial hyaloclastic eruption under a thick ice cap, which shattered the lava into glass, ash and sand, which has since weathered to yellow palagonite layers. The second phase was a lava eruption into a meltwater glacial lake contained in the ice cap, which resulted in volcanic breccia and basalt pillow lava (boulders of this can be seen along the shore). The final phase was subaerial basalt lava flows on top of the previous volcanic deposits after the lake drained or boiled away.
Geologically, the area makes up the Cockburn Island Formation, which was studied extensively in the late 1990s by H. A. Jonkers. Rocks found on the island are volcanic, and the island is characterized by its "precipitous cliffs". A "Pecten conglomerate" from the late Pliocene or early Pleistocene period has been identified on the island, situated on a wave-cut platform at 720–820 ft. The island is a rare volcano type called a tuya, or moberg, which was formed by a three-stage eruption sequence below an ice cap. The first stage was a subglacial hyaloclastic eruption under a thick ice cap, which shattered the lava into glass, ash and sand, which has since weathered to yellow palagonite layers. The second phase was a lava eruption into a meltwater glacial lake contained in the ice cap, which resulted in volcanic breccia and basalt pillow lava (boulders of this can be seen along the shore). The final phase was subaerial basalt lava flows on top of the previous volcanic deposits after the lake drained or boiled away.
Map - Cockburn Island (Cockburn Island)
Map
Country - Antarctica
Antarctica is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of 14200000 km2. Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of 1.9 km.
Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over 200 mm along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost 60 m. Antarctica holds the record for the lowest measured temperature on Earth, −89.2 C. The coastal regions can reach temperatures over 10 C in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation occurs, it is mostly in the form of lichen or moss.
Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over 200 mm along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost 60 m. Antarctica holds the record for the lowest measured temperature on Earth, −89.2 C. The coastal regions can reach temperatures over 10 C in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation occurs, it is mostly in the form of lichen or moss.