Mount Erebus

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Mount Erebus, 1972
Elevation 3794 metres (12,447 ft) [1]
Location Ross Island, Antarctica
Prominence 3794 metres (12,447 ft) [1]Ranked 34th
Coordinates 77°32′S 167°10′E / -77.53, 167.17Coordinates: 77°32′S 167°10′E / -77.53, 167.17
Topo map Ross Island C77190S1
Type Stratovolcano
Age of rock About 1,000,000 years
Last eruption 2008 (continuing)
First ascent 1908 by Edgeworth David and party [2]
Easiest route Basic snow & ice climb
Listing Ultra

Mount Erebus in Antarctica is the southernmost active volcano on Earth. With a summit elevation of 3794 metres (12,447 ft), 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 New Mexico Tech.[3]

Mount Erebus, on Ross Island in Antarctica, is the continent's largest volcano by volume, and second only to Mount Sidley in altitude. This is a view from McMurdo Station.

Mount Erebus was discovered on January 27, 1841 (and observed to be in eruption) [4] by polar explorer Sir James Clark Ross who named it and Mount Terror after his ships, Erebus and Terror (which were also used by Sir John Franklin on his disastrous Arctic expedition). It was first climbed (to the rim) by members of Sir Ernest Shackleton's party in 1908. Erebus was a primordial Greek god, the son of Chaos.

The first known solo ascent of Mount Erebus was accomplished by British mountaineer Roger Mear in March 1985, a member of Robert Swan's "In the Footsteps of Scott" expedition.[5] On January 19-20, 1991, Charles J. Blackmer, an iron-worker for many years at McMurdo Station and the South Pole, accomplished a solo ascent in approximately seventeen hours, an exploit cited in two books about Antarctic experiences, Terra Incognita by Sara Wheeler and Big Dead Place by Nicholas Johnson.

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[edit] Geology and volcanology

Mount Erebus is currently the most active volcano in Antarctica today. The summit contains a persistent convecting phonolitic lava lake, one of a very few 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.[6][7] 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 the proximity (thirty-five kilometres) of McMurdo Station (U.S.) and Scott Base (N.Z.), both sited on Ross Island.

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 were 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 is 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. It is within this summit cone that the active lava lake continuously degasses.

[edit] 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.

[edit] Gallery

[edit] See also

[edit] References

Specific
  1. ^ a b "Erebus". Global Volcanism Program. Smithsonian Institution. Retrieved on 2008-12-29.
  2. ^ "Antarctic explorers". Australian Antarctic Division. Retrieved on 2008-12-29.
  3. ^ "Mount Erebus Volcano Observatory". New Mexico Tech. Retrieved on 2008-12-29.
  4. ^ Ross, Voyage to the Southern Seas, vol. i, p. 216-18
  5. ^ Mear, Roger and Robert Swan, In the Footsteps of Scott, p. 95-104
  6. ^ Kyle, P. R. (Ed.), Volcanological and Environmental Studies of Mount Erebus, Antarctica, Antarctic Research Series, American Geophysical Union, Washington DC, 1994.
  7. ^ Aster R., Mah, S., Kyle, P., McIntosh, W., Dunbar, N., and J. Johnson, Very long period oscillations of Mount Erebus volcano, J. Geophys. Res., 108, 2522, doi:10 .1029/2002JB002101, 2003.
General

[edit] External links

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