Past 40 years sees drop in Arctic summer sea ice: StatsCan
Largest drops in northern Labrador Sea, Hudson Strait
You’ll find less Arctic summer sea ice wherever you look in Canada’s North.
Over the past 40 years, the average area covered by sea ice during summer has declined in all its nine sea ice regions, Statistics Canada said Dec. 8.
In Hudson Strait, the drop means there’s about half the sea ice cover during recent summers than was usual in the late 1960s.
Ice cover has also declined in two of three northern shipping route regions since 1968, said Statistics Canada’s EnviroStats report, which looked at data collected by the Canadian Ice Service from 1968 to 2010.
The largest declines during every ten-year period of the past 40 years occurred in five southern and eastern sea ice regions:
• the northern Labrador Sea, where sea ice decreased at a rate of 1,536 square kilometres, or 17 per decade;
• Hudson Strait, down 4,947 sq. km. or 16 per cent per decade;
• Davis Strait, down 6,581 sq. km. or 14 per cent per decade;
• Hudson Bay, down 16,605 sq. km, or 11 per cent, per decade ; and,
• Baffin Bay, down 18,658 sq. km. or 10 per decade.
Two shipping route regions have also opened up since 1968.
In Arctic Bridge route, across the top of Hudson Bay into Hudson Strait, ice cover fell at a rate of 14,147 sq. km. or 15 per cent per decade.
In southern route of the Northwest Passage, ice cover fell by 6,986 sq. kq. per decade.
The Northwest Passage shipping routes are usually blocked by sea ice during all seasons, “significantly limiting any navigation,” EnviroStats said.
But all remained navigable for a short period of time in late summer and early fall of 2007, it noted.
This EnviroStats study also looked multi-year ice cover, which is the area covered by older ice that has survived at least one summer’s melt.
Of the seven regions reporting multi-year sea ice, only the Baffin Bay region showed a downward trend.