BUFFALO, N.Y. -- A new Arctic study in the journal Science is
helping to unravel an important mystery surrounding climate change:
How quickly glaciers can melt and grow in response to shifts in
According to the new research, glaciers on Canada's Baffin
Island expanded rapidly during a brief cold snap about 8,200 years
ago. The discovery adds to a growing body of evidence showing that
ice sheets reacted rapidly in the past to cooling or warming,
raising concerns that they could do so again as the Earth heats
"One of the questions scientists have been asking is how long it
takes for these huge chunks of ice to respond to a global climate
phenomenon," said study co-author Jason Briner, PhD, a University
at Buffalo associate professor of geology. "People don't know
whether glaciers can respond quickly enough to matter to our
grandchildren, and we're trying to answer this from a geological
perspective, by looking at Earth's history."
"What we're seeing," he added, "is that these ice sheets are
surprisingly sensitive to even short periods of temperature
Briner's colleagues on the study included lead author Nicolas
Young, who worked on the study as part of his PhD at UB and is now
a postdoctoral researcher at Columbia University's Lamont-Doherty
Earth Observatory; Dylan H. Rood of the Scottish Universities
Environmental Research Centre and the University of California,
Santa Barbara; and Robert C. Finkel of UC Berkeley.
The research, scheduled to appear in Science on Sept. 14, found
that mountain glaciers on Baffin Island, along with a massive North
American ice sheet, expanded quickly when the Earth cooled about
8,200 years ago.
The finding was surprising because the cold snap was extremely
short-lived: The temperature fell for only a few decades, and then
returned to previous levels within 150 years or so.
"It's not at all amazing that a small local glacier would grow
in response to an event like this, but it is incredible that a
large ice sheet would do the same," Young said.
To conduct the research, Briner led a team to Baffin Island to
read the landscape for clues about the pre-historical size and
activity of glaciers that covered the island.
Moraines -- piles of rocks and debris that glaciers deposit
while expanding -- provided valuable information. By dating these
and other geological features, the scientists were able to deduce
that glaciers expanded rapidly on Baffin Island about 8,200 years
ago, a period coinciding with a short-lived cold snap.
The researchers also found that Baffin Island's glaciers
appeared to have been larger during this brief period of cooling
than during the Younger Dryas period, a much more severe episode of
cooling that began about 13,000 years ago and lasted more than a
This counterintuitive finding suggests that unexpected factors
may govern a glacier's response to climate change.
With regard to Baffin Island, the study's authors say that while
overall cooling may have been more intense during the Younger
Dryas, summer temperatures may have actually decreased more during
the shift 8,200 years ago. These colder summers could have fueled
the glaciers' rapid advance, decreasing the length of time that ice
melted during the summer.
Detailed analyses of this kind will be critical to developing
accurate models for predicting how future climate change will
affect glaciers around the world, Briner said.
The study was funded by the National Science Foundation.