Mount Erebus

Mount Erebus in Antarctica is the southernmost historically active volcano on Earth. With a summit elevation of , it is located on Ross Island, which is also home to three inactive volcanoes, notably Mount Terror. Mount Erebus is part of the Pacific Ring of Fire, which includes over 160 active volcanoes.

The volcano has been observed to be continuously active since 1972 and is the site of the Mount Erebus Volcano Observatory run by the New Mexico Institute of Mining and Technology.

Discovery and naming

Climbing

Geology and volcanology

Mount Erebus is currently the most active volcano in Antarctica and is the current eruptive zone of the Erebus hotspot. The summit contains a persistent convecting phonolitic lava lake, one of five long-lasting lava lakes on Earth. Characteristic eruptive activity consists of Strombolian eruptions from the lava lake or from one of several subsidiary vents, all lying within the volcano's inner crater. The volcano is scientifically remarkable in that its relatively low-level and unusually persistent eruptive activity enables long-term volcanological study of a Strombolian eruptive system very close (hundreds of metres) to the active vents, a characteristic shared with only a few volcanos planetarily, such as Stromboli in Italy. Scientific study of the volcano is also facilitated by their proximity to McMurdo Station (U.S.) and Scott Base (N.Z.), both sited on Ross Island approximately thirty-five kilometres away.

Mount Erebus is classified as a polygenetic stratovolcano. The bottom half of the volcano is a shield and the top half is a stratocone (Mount Etna is like this as well). The composition of the current eruptive products of Erebus is anorthoclase-porphyric tephritic phonolite and phonolite, which constitute the bulk of exposed lava flow on the volcano. The oldest eruptive products consist of relatively undifferentiated and non-viscous basanitic lavas that form the low, broad platform shield of the Erebus edifice. Slightly younger basanite and phonotephrite lavas crop out on Fang Ridge — an eroded remnant of an early Erebus volcano — and at other isolated locations on the flanks of the Erebus edifice.

Lava flows of more viscous phonotephrite, tephriphonolite and trachyte erupted after the basanite. The upper slopes of Mount Erebus are dominated by steeply dipping (−30°) tephritic phonolite lava flows with large scale flow levees. A conspicuous break in slope at approximately 3,200 metres calls attention to a summit plateau representing a caldera less than one hundred millennia old. The summit caldera itself is filled with small volume tephritic phonolite and phonolite lava flows. In the center of the summit caldera is a small, steep-sided cone composed primarily of decomposed lava bombs and a large deposit of anorthoclase crystals known as Erebus Crystals. It is within this summit cone that the active lava lake continuously degasses.

Air disaster

Air New Zealand Flight 901 was a scheduled passenger transport service from Auckland Airport in New Zealand to Antarctica and return, without an intermediate stop. The Air New Zealand flyover service, for the purposes of Antarctic sightseeing, was operated with McDonnell Douglas DC-10-30 aircraft and began in February 1977. The flight crashed into Mount Erebus in sector whiteout conditions on November 28, 1979, killing all 257 people aboard. Air New Zealand discontinued the service after the crash.

During the Antarctic summer, snow melt on the flanks of Mount Erebus continually brings debris from the crash to the surface of the snow; it is plainly visible from the air.

Gallery

See also

References

;General

External links

Category:Active volcanoes Category:Extreme points of Earth Category:Mountains of Antarctica Category:Ross Island Category:Stratovolcanoes Category:Volcanoes of Antarctica Category:VEI-2 volcanoes Category:Hotspot volcanoes Category:Mountains