Institute eyes Prince Edward Island 9,000 years ago

Institute eyes Prince Edward Island 9,000 years ago


It was a land of lakes and rivers where hunters used stone spearpoints to pursue caribou herds in the shadow of massive glaciers, where walrus and seal were harvested on the shores of an emerging sea.
Today it’s an area better known as a lobster fishing ground – the Northumberland Strait.

Researchers at the Bedford Institute of Oceanography are offering the public a look at the strait 9,000 years ago, when the seabed was dry land and the whole of the Maritimes was a single land mass called Northumbria.

John Shaw, a geologist who studies sea level change, says the east coast of Canada was a dramatically different place at the end of the last ice age.

“The National Research Council has sponsored a detailed sonar map of the Northumberland Strait back in 1995 and what it showed was a very detailed picture of this land where you can still see old lakebeds as well as a river running along the length of the strait. When we combine that with what we know about sea level change we can see that this area once looked completely different,” Shaw said in an interview with this newspaper.

“Nine thousand years ago, P.E.I. was connected to the mainland. It was more than a land-bridge. Basically from Halifax it would have been possible to walk on dry land all the way out into the Gulf of St. Lawrence area almost to the Magdalen Islands. Those Islands would have been a single larger land mass fairly near to the shore of the mainland.”

Shaw said the dry landscape of the ancient Maritimes was caused by the weight a land upsurge produced by the weight of ice age glaciers pressing down other points of land. With the ice sheet now largely restricted to the arctic, the Island has been gradually settling down.

“Sea levels rose to the point that P.E.I. became an island around 6,000 years ago. They’re still continuing to rise on the Island. People may tend to think that rising sea levels on P.E.I. are due to global warming, but that’s a small part of it, most of the change is because the land is sinking down into the sea,” said Shaw.

At Charlottetown that change in sea levels has produced a rise of 32 centimetres on a gauge posted in 1911.
Shaw said it may be hard for some people to get their heads around the rate of change that happens in landscapes, but he said it’s not unusual for a geological event like the ice age to still be producing effects.