Volcanic Hazard Assessment of Mount Erebus, Ross Island, Antarctica

Abstract

Mount Erebus was discovered by James Clark Ross and his crew on the 27th of January 1841 and was named after the ship he was travelling on, Erebus (Kyle et al., 1982). Mount Erebus is located at 77.58 os, 167.17 OE on Ross Island, Antarctica and is the world's most southerly active volcano (Figure l). It sits within a tectonic plate in an area known as the Erebus Volcanic Province in McMurdo Sound. It is estimated that approximately 40 million years ago volcanism started in the region and has persisted until today, giving rise to land features such as Black Island, White Island, Mount Terror, Mount Discovery and Mount Erebus (Ross Sea Region Report, 2001). Mount Erebus is one of two active volcanoes in the Ross Sea Region, the other being Mount Melbourne on the coast of North Victoria Land, which has weak thermal activity (Kyle et al., 1982). Erebus is the largest of three volcanoes that make up Ross Island and is distinctive in that it is predominantly composed of anorthoclase phonolite lavas, whereas Mount Byrd and Mount Terror are basaltic lavas. It is a strato-volcano reaching 3,794 m high and is estimated to be between 0.93 - 0.2 million years old. It is one of four active volcanoes in the world with a persistent lava lake within the summit crater. The summit crater is approximately 600 m north-south long by about 500 m eæst-west. Within the crater there is a nearly flat floor about 160 m below the summit and another inner crater at the north end of the main crater. This inner crater is about 250 m in diameter and about 100 m deep and is divided by an east west ridge. The south section is covered with snow and is the site of several noisy fumaroles, whereas in the northern half is the lava lake and an active vent where most of the explosive activity occurs (Kyle et al., 1982; Dibble et al., 1984). Mount Erebus was discovered by James Clark Ross and his crew on the 27th of January 1841 and was named after the ship he was travelling on, Erebus (Kyle et al., 1982). Mount Erebus is located at 77.58 os, 167.17 OE on Ross Island, Antarctica and is the world's most southerly active volcano (Figure l). It sits within a tectonic plate in an area known as the Erebus Volcanic Province in McMurdo Sound. It is estimated that approximately 40 million years ago volcanism started in the region and has persisted until today, giving rise to land features such as Black Island, White Island, Mount Terror, Mount Discovery and Mount Erebus (Ross Sea Region Report, 2001). Mount Erebus is one of two active volcanoes in the Ross Sea Region, the other being Mount Melbourne on the coast of North Victoria Land, which has weak thermal activity (Kyle et al., 1982). Erebus is the largest of three volcanoes that make up Ross Island and is distinctive in that it is predominantly composed of anorthoclase phonolite lavas, whereas Mount Byrd and Mount Terror are basaltic lavas. It is a strato-volcano reaching 3,794 m high and is estimated to be between 0.93 - 0.2 million years old. It is one of four active volcanoes in the world with a persistent lava lake within the summit crater. The summit crater is approximately 600 m north-south long by about 500 m eæst-west. Within the crater there is a nearly flat floor about 160 m below the summit and another inner crater at the north end of the main crater. This inner crater is about 250 m in diameter and about 100 m deep and is divided by an east west ridge. The south section is covered with snow and is the site of several noisy fumaroles, whereas in the northern half is the lava lake and an active vent where most of the explosive activity occurs (Kyle et al., 1982; Dibble et al., 1984).