11-08-04

Melting permafrost in the high Arctic could be causing a massive underwater landslide that may interfere with efforts to explore for oil and gas, scientists say.

Researchers on the Amundsen icebreaker discovered the "slump" when they were surveying the MacKenzie shelf with a multi-beam sonar.

The slump is located on the floor of the Beaufort Sea, about 25 km northwest of Tuktoyaktuk.

"If we were to install a drilling platform that was anchored in the bottom in this area, it would be extremely dangerous because the bottom is unstable," said Andre Rochon, an earth scientist at the University of Quebec in Rimouski. "So if we would want to build a pipeline to transport gas or oil, then it's an unstable region and we would have to try to avoid that area, to avoid accidents."

The 10-metre wide slump is much larger than any known feature of this type, especially in the ocean, according to Prof. David Scott of Dalhousie University in Halifax.

"If that thing actually gave loose and started slumping, it would transfer tens of cubic km of sediment to the deep sea," said Scott, a paleo-oceanography researcher.

The slump is similar to those that occur when frozen ground begins to melt and creep, said Rochon.
"It's probably being caused by the thawing of the permafrost. What we can see on the image tells us it's a process that's been going on for quite some time," said Rochon. "We have no way of saying if it's being accelerated by the actual warming that we observe today."

Researchers will return to the area next year to try to determine the extent of the slump, and how fast it is moving.

Source: CBC News