Scott Dallimore of the Geological Survey of Canada stands by exposed permafrost near Tuktoyaktuk, N.W.T., in August 2008. "Permafrost is frozen ground, and in this area, perhaps 400 metres of frozen ground," he told CBC News. (CBC)

Arctic residents living along the coast of the Beaufort Sea have become acutely sensitive to the forces of nature, with scientists warning that rising seas and melting permafrost could erode away at their communities.

Parts of Tuktoyaktuk, a hamlet in the northwest corner of the Northwest Territories, were under sea water last summer, and flooding is becoming an annual occurrence, the community's mayor said.

"This place fills up with water just about all the time. Every year you can expect it two or three times to be flooded," Mayor Mervin Gruben said.

"You can't drive from here to the other side because all this will be flooded here. That gravel pile was an island. Our swimming pool, that was an island. All this was just covered in water here."

Gruben said he's noticed the warmer-than-usual weather in recent years, and is worried that climate change will lead to rising sea water and more storm surges.

"We used to have houses all over.... There was even actually a lake, from what the elders tell me," he said.

"That's not very long; maybe 50, 60 years ago," he added. "This is all gone."

Just off the northern coast of neighbouring Yukon, Herschel Island, the site of a territorial park and a traditional whaling community, has also seen shoreline erosion recently. Strong winds have even washed out the island's airport runway several times, rendering it inaccessible.

"The factors which influence erosion are getting worse.... There's going to be more open water, there's going to be open water for longer periods of time," said Steve Solomon, a coastal geologist with Natural Resources Canada.

"The land is going down, the sea level is rising. In the long term, that's not a very healthy scenario."

A rising sea poses a great threat to Tuktoyaktuk, which is built on permafrost. The sea can expose, erode and melt that permafrost over time.

"One of the key issues for this community is what happens if permafrost warms by, say, 2 C?" said Scott Dallimore, a research scientist with the Geological Survey of Canada.

"What will that temperature change mean to the stability of this deeper, frozen permafrost, but also the surface layer and its impact on degrading permafrost at the coastline?"

Any summer melting of that permafrost can be sped up by surface infrastructure such as buildings and roads, Gruben said.

"It's just melting, and our roads are sinking below ground level, disappearing into the tundra," he said. "The graveyard is shifting."

Gruben said he does not like to think about what Tuktoyaktuk will lose in the next 50 to 100 years. However, his council has started forcing new construction in the community to go further inland.