Washington: Arctic sea ice is at its record
low in the recent geologic history, a major international
study has claimed.
The first comprehensive history of Arctic ice, carried
out by a team of scientists from five countries, found that
the recent retreat is the worst in thousands of years.
"The ice loss that we see today -- the ice loss that
started in the early 20th Century and sped up during the last
30 years -- appears to be unmatched over at least the last few
thousand years," said Leonid Polyak, a research scientist at
Byrd Polar Research Center at Ohio State University.
Polyak is lead author of the research paper which will be
published in the upcoming issue of Quarternary Science
For decades, scientists have strived to collect sediment
cores from the difficult-to-access Arctic Ocean floor, to
discover what the Arctic was like in the past. Their most
recent goal: to bring a long-term perspective to the ice loss
we see today.
Now, the team led by Ohio State University has
re-examined the data from past and ongoing studies -- nearly
300 in all -- and combined them to form a big-picture view of
the pole`s climate history stretching back millions of years,
the university said.
Satellites can provide detailed measures of how much ice
is covering the pole right now, but sediment cores are like
fossils of the ocean`s history, said Polyak.
"Sediment cores are essentially a record of sediments
that settled at the sea floor, layer by layer, and they record
the conditions of the ocean system during the time they
"When we look carefully at various chemical and
biological components of the sediment, and how the sediment is
distributed -- then, with certain skills and luck, we
can reconstruct the conditions at the time the sediment was
For example, scientists can search for a biochemical
marker that is tied to certain species of algae that live only
in ice. If that marker is present in the sediment, then that
location was likely covered in ice at the time, he explained.