'First time we've heard of this': Wide fissure opens on Arctic sea ice

In about 24 hours last week a natural phenomenon near Cambridge Bay, Nunavut, developed from a minor inconvenience into a potentially life-threatening hazard.

It's not unusual for underwater currents in the Queen Maud Gulf, south of Cambridge Bay, to cause small fissures in sea ice. But last week a fissure opened that was large enough to swallow a snowmobile and rider.

The fissure was 15 to 20 kilometres long and up to 7.5 metres wide at points, according to Angulalik Pedersen, who works with Cambridge Bay Ground Search and Rescue.

"This is the first time we've heard of this," Pedersen said last Thursday. "There's usually a lead there but you know, it's about a foot wide, or two feet wide, and it's still frozen so you can cross safely. But in the last 24 hours it's widened out to 20, 25 feet."

A lead is a channel of water through an ice field or floe.

Pedersen said the ice around the fissure appeared to be as thick as he might have expected.

"From what we saw pushed up on the edges it was four to five feet thick, so normal thickness for that area I guess."

It's one of our main snowmobile highways.- Angulalik Pedersen, Cambridge Bay Search and Rescue

Pedersen suspects strong underwater currents in the constriction between the Queen Maud Gulf and the Dease Strait were to blame. It's a stretch of sea ice used by community members to reach mainland Nunavut from Cambridge Bay, on Victoria Island.

"It's one of our main snowmobile highways," Pedersen said. He estimates that up to 50 different parties make return trips every week this time of the year, with some making multiple trips.

Long-time community members surprised

"Our main concern was a lot of the hunters … still down on the mainland," Pedersen said last week. "They don't know about this.

"We got the word out as soon as we heard here in the community and we put out the maps … But our concern was those that don't have contact with the community."

Pedersen said he and others went out onto the ice to set up signs directing unaware travellers away from the open water. He said the detour was about 12 to 15 kilometres long.

Pedersen, who's lived in Cambridge Bay for about five years and has never seen the ice behave like this before, said he's since talked to other community members about the opening. Long-time community members were as surprised as Pedersen about the event. 

"Everyone I've talked to has said the same thing…. Elders are saying the same thing — they haven't seen that before in this area."

On Tuesday Pedersen said the fissure remains, although it moves around a bit depending on the winds.

"Hunters have been using our markers," Pedersen said. "People are still going down to the mainland and coming back. But the ice is still in the same condition."

Pedersen said there haven't been any incidents with travellers, but quick action last week was necessary.

"If somebody didn't see this, or the signs weren't there, or somebody didn't know, they literally could have driven straight into it because with the flat light we have here right now, you can't tell the difference.

"You jump off of a ledge and into the water … you don't see it until you're over it."