Geoscience Reference
In-Depth Information
In 1992 the Carnegie Mellon University designed and developed a robot
'
Dante
'
to enter and study the unique convecting magma lake inside the Mt Erebus inner
crater. Dante was designed as a tethered walking robot capable of climbing steep
slopes and self-sustained operation in the harsh Antarctic climate. Unfortunately,
a break in a
fibre optic cable linking the 8-foot (2.4m) high spidery robot to the
control hut halted the mission as Dante made its way down the steep and
treacherous crater walls. The expedition demonstrated the advancing state-of-
art in mobile robotics and the future potential of robotic explorers in remote
locations such as Antarctica.
As is always the case in Antarctica, many exciting discoveries remain
hidden beneath the ice. Scientists have recently, and for the
first time, discovered
exciting evidence for a volcano completely covered by the thick Antarctic ice sheet.
They, using ice-penetrating radar, have estimated that the volcano last erupted about
2300 years ago, yet remains active today. This was probably the biggest eruption
in Antarctica during the last 10 000 years. It blew a substantial hole in the ice
sheet close to the Pine Island Glacier on the West Antarctic icesheet and
generated a plume of ash and gas that rose 12 km into the air, covering an area
of 20 000 km
2
. Although ice has buried the unnamed volcano, molten rock is still
erupting below the ice. It remains to be seen how many more such volcanoes exist
beneath the ice and whether our concept of a sleeping giant is correct. Like Mt
Erebus, the buried volcano does not relate to a plate boundary but may be the
last vestige of a previously active rifted landscape that had many more active
volcanoes than today.
Birth of Gondwana
In contrast to the present isolated position of Antarctica astride the South
Pole, the continent has amalgamated and combined with other continental
fragments and rifted apart to form new ocean seaways throughout geological
time. For much of the Phanerozoic (from 540 to 180million years ago) Antarctica
was the keystone of the Gondwana supercontinent. It was joined centrally to South
America, India, Africa, Australia and New Zealand. More amazingly, prior to
Gondwana, many scientists have speculated that East Antarctica may have been
joined to the western side of America in a continent called Rodinia. The hypothesis
has become known as the SWEAT hypothesis (South West US
East Antarctica
Connection). As North America left East Antarctica scattered continental blocks
came together again to form Gondwana about 550million years ago at a time
when there was rapid evolution of multicellular plants and animals. Where
adjacent continental blocks collided, Himalayan-sized mountain chains traversed
the continent
-
-
the deeply eroded remnants of these sutures can be seen today in the
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