From the air, Trapridge Glacier resembles a pie crust scored and
ready for global warming.
This is the view UBC’s six-member glaciology team sees before landing
via helicopter at its base camp steps from the glacier’s edge. The
lines visible on the surface are stress fractures in the ice caused
by powerful forces under the glacier as it slides over an uneven
bed.
Led by Prof. Garry Clarke of UBC’s Dept. of Earth and Ocean Sciences,
the UBC team is attempting to unlock secrets of these subglacial
processes and their relationship to global climate change.
“Everyone is interested in coming up with computer models to predict
future climates but the problem is that you have to wait for the
future for any validation,” says Clarke. “The only good way to develop
computer models of world climate is by attempting to `predict’ past
climates.”
For Clarke and company, glaciers hold the key.
The current team is observing glacial processes in action on Trapridge
and plans to use what it learns to simulate the last ice age from
100,000 years ago to the present. Team efforts are part of a national
study, called Climate System History and Dynamics, which is attempting
to map the relationship between glaciers, oceans, peat bogs and
the atmosphere.
“As the Earth heats up, the ice sheets melt and they do something
to the ocean which responds and does something to the climate,”
says Clarke. “Everything is threaded together in a complex matrix.”
Clarke and others believe that the subglacial processes underlying
Trapridge, which cause it to surge and retreat in regular cycles,
mirror those of its continent-sized counterparts. A model of how
water and sedimentation systems operate under Trapridge should shed
light on how massive ice sheets gave water to the oceans during
the last ice age and continue to do so today.
Says Clarke: “There seems to be evidence that the circulation of
the oceans can flick on and off, a process which is triggered by
the continental ice sheets. If these circulation patterns are altered
in some way, then it’s generally presumed that large-scale climate
consequences will follow.”
-30-
