Nah, yang ini bukan di film The Day after Tomorrow, tetapi kenyataan. Di kedua kutub
Bumi tersimpan catatan-catatan iklim masa lalu. Barangkali ada yang bisa digali dan
dipelajari untuk kondisi iklim masa depan sebab perulangan peristiwa adalah ciri
gejala alam di Bumi. Inilah untuk pertama kalinya Arktika akan dibor sampai kedalaman
1500 meter, membuka semua catatan isotop oksigen yang membeku di kristal es. Tetapi,
team ilmuwan dan driller harus berlomba dengan datangnya arctic winter, kalau tidak
mau terjebak dan tewas seperti Alfred Wegener...
Salam,
awang
Climatologists brave bergs for core data
Icebreakers to protect drillers in Arctic Ocean.
7 June 2004
JIM GILES
A converted icebreaking ship of the former Soviet Union is to head an ocean convoy
that will take 200 climate scientists and support staff on a unique mission this
summer.
The Sovetskiy Soyuz will sail north from Tromso, Norway, on 8 August, clearing a path
through the Arctic ice for a team of researchers who want to extract a core from the
ocean floor. No one has been able to dodge icebergs and drill into the Arctic floor
before, but if the team succeed they will generate data to predict future climate
change.
Once in position, around 250 kilometres from the North Pole, the Soyuz will protect
the convoy's drilling ship: the Vidar Viking. Researchers on the Viking will try to
extract samples from as deep as 1,500 metres below the sea floor, despite the fact
that the ship cannot move more than 50 metres sideways without damaging its drilling
equipment.
The crew is aware of the dangers of ice in the Arctic. "The ship can�t take hits from
icebergs and remain in position," says operations manager Alister Skinner of the
British Geological Survey in Edinburgh.
To help protect Soyuz, helicopters will circle the area and track ice floes. If
visibility is poor, beacons will be placed on nearby ice sheets and tracked by
satellites. Captains on board the Soyuz and another smaller icebreaker, the Oden, will
use signals from the helicopters and satellites to intercept and break up incoming ice.
The team, which will target the Lomonosov Ridge, a 1,500-kilometre chain of mountains
that rises 3 kilometres above the sea floor, will have to work fast. "We have just 35
days to get out there, drill and get back," says Skinner. Dally any longer, he says,
and the convoy risks being caught in the Arctic winter.
If they succeed, the researchers will gain a missing piece of the global climate
record. As sediment falls through the ocean and collects on the sea floor, it takes
with it a record of the temperature and atmospheric conditions at the time it fell. By
analysing the sediment, climate experts can reconstruct those conditions, but they
need a core drilled from the Arctic to add to those from other oceans.
Such data will be valuable, as conditions in the Arctic influence climate patterns
around the world. Arctic ice helps to cools the Earth, for example, by reflecting
sunlight back into space. "It's very difficult to model climate change without records
of sea ice," says Jan Backman of Stockholm University in Sweden, the mission's joint
chief scientist
The US$10-million project, which is funded by 15 European countries, is the first of a
slew of new ocean-drilling projects organized by the Integrated Ocean Drilling
Program, an international effort launched last October.
The programme's flagship is the Chikyu, a US$500-million Japanese vessel designed to
set new drilling records by reaching 7 kilometres below the sea floor. The ship's
first mission is scheduled for October 2006.
References
1. Dalton, R. & Cyranoski, D. et al. Nature, 426, 492 - 494 (2003)|Article|
� Nature News Service / Macmillan Magazines Ltd 2004
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