Mount Erebus
Mount Erebus in
Antarctica is the southernmost active
volcano on Earth.
3794 metres (12,448 ft) high, it is located on
Ross Island, which is also home to three inactive volcanoes, notably
Mt. Terror.
The volcano has been continuously active since
1972 and is the site of the Mt. Erebus Volcano Observatory run by the
New Mexico Institute of Mining and Technology. The crater is home to one of the very few permanent
lava lakes in the world.
Mount Erebus was discovered in
1841 by polar explorer Sir
James Clark Ross (whose ships were named
Erebus and
Terror; these ships were also used by Sir
John Franklin on his disastrous
Arctic expedition), and first climbed (to the rim) by members of Sir
Ernest Shackleton's party in
1908. The ships and the volcano were all named for
Erebus, a primordial
Greek god, the son of
Chaos.
Air New Zealand Flight 901 was a non-scheduled passenger transport service from
Auckland International Airport in
New Zealand to
Antarctica and return. The
Air New Zealand 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 1979, killing all 257 people aboard.
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Satellite picture of Mount Erebus |
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Topographic map of Ross Island (1:250,000 scale) from USGS Ross Island |
Mt. Erebus is currently the most active
volcano in
Antarctica. The summit of Mt. Erebus contains a persistent convecting lava lake which undergoes several
strombolian style eruptions daily. In
2005, small ash eruptions and even a small lava flow were observed coming from vents near the lava lake. The bottom half of the volcano is a shield and the top half is a stratocone (
Mount Etna is like this as well).
Mt. Erebus (3794 meters above sea level) is classified as a
polygenetic stratovolcano. The composition of the current eruptive activity on Mt. Erebus is
anorthoclase-
porphyric tephritic phonolite and
phonolite, which constitute the bulk of exposed lava flow on the volcano. The oldest eruptive products from Mt. Erebus 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 Mt. Erebus edifice.
Lava flows of more viscous
phonotephrite,
tephriphonolite and
trachyte were erupted after the
basanite. The upper slopes of Mt. Erebus are dominated by steeply dipping (~30°)
tephritic phonolite lava flows with large scale flow levees. A conspicuous break in slope at approximately 3200 meters is a summit plateau representing a
caldera less than 100,000 years 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. The volcano frequently produces Strombolian eruptions from several vents within its innermost crater, with the most frequent events arising from large (up to 10-m diameter) gas bubbles emerging explosively from the lava lake.
*
Nimrod Expedition - first ascent of Mount Erebus
*
Global Volcanism Program*
A picture from space of the lava lake at the summit of Mt Erebus*
Erebus Glacier Tongue *
The Mount Erebus Volcano Observatory website at New Mexico Tech includes a live cam of the volcano, video clips of eruptions and other geological information. The Observatory is supported by the National Science Foundation Office of Polar Programs
