Canada's Shrinking Ice Caps
Earth's ice-covered polar regions help to keep our climate cool and hold tremendous amounts of fresh water locked up in their glaciers, ice caps, and ice sheets. If all the ice contained in these vast freshwater reservoirs were to melt, sea levels would rise nearly 220 feet. However, when most people think of polar ice, they usually do not think of Canada, the location of only a small percentage of the Arctic's polar land ice.
Recent research conducted by NASA scientists has revealed that Canada's ice caps and glaciers have important connections to Earth’s changing climate, and they have a strong potential for contributing to sea level rise.
Canada's Arctic region is covered by approximately 150,000 square kilometers (57,660 square miles) of land ice. This is much smaller than Antarctica's 13.5 million square kilometers (5.2 million square miles), and Greenland's 1.7 million square kilometers (650,000 square miles) of ice coverage, but still quite significant.
Waleed Abdalati, Head of the Cryospheric Sciences Branch at NASA's Goddard Space Flight Center (GSFC), Greenbelt, Md., published research recently in the Journal of Geophysical Research showing that Canada's Arctic ice is one of the more significant and immediate sources of world-wide changes in sea levels.
Image to the right: During the research campaigns, first in 1995 and then in 2000, Abdalati and his colleagues flew the NASA P-3 aircraft over the Canada Arctic Archipelago. Shown here is the location map of the 2000 flight lines (repeat surveys of the 1995 lines) where flights were conducted out of Pangnirtung, Clyde River, Grise Fiord, and Eureka. Weather station data used in this analysis were from Eureka, Alert, Resolute, Clyde River, Iqaluit, Egedesminde, and Dewar Lakes. Click on image for a larger view. Image credit: Waleed Abdalati, NASA Goddard Space Flight Center.
Abdalati and his colleagues say that Canada's Arctic ice is important because of the wide area covered by these ice caps and the dramatic changes that have taken place in the Arctic climate in recent years. Studying this region will help researchers understand how much and in what ways Arctic glaciers and ice caps are contributing to sea level rise.
"The ice-covered parts of the world, and, in particular, of the Arctic are considered to be very sensitive to change," said Abdalati.
To study Canada's ice caps, Abdalati and his colleagues used a laser mounted on an airplane to measure the precise elevation of the ice surface. By making these measurements over many of the Canadian ice caps once in 1995 and repeating them again in 2000, they were able to determine how much the thickness of the ice sheet changed.
The researchers found that in areas where the ice generally melts very little, there was slight thickening of some ice caps, which could be due to the accumulation of increased precipitation; however, overall they found that the ice caps and glaciers were thinning at the lower elevations where melt occurs. They determined that the ice loss associated with these combined effects contributed to 0.065 millimeters (0.002 inches) per year to sea level rise during the 1995-2000 time period.
Image to the left: This image from the NASA P-3 research aircraft was taken after surveying the Barnes ice cap on Baffin Island. Image credit: James Yungel, NASA Wallops flight Facility.
"This research is significant because it is the first large-scale assessment of Canada's ice cap contribution to sea level rise, which has never been put into a comprehensive picture before," said Abdalati. "The ice caps in the Canadian Arctic are shrinking, and though they are relatively small compared to areas like Greenland and Antarctica, their short-term contributions to sea level cannot be ignored."
NASA Langley Research Center