A pocket of warm salt water located 50 metres below the western Arctic Ocean could be a “ticking time bomb” set to cause significant ice loss if it is released, according to a new study in the journal Science Advances.
The existence of the layer itself, located beneath the Canada Basin north of Alaska and parts of the Yukon and Northwest Territories, is no news to scientists, CBC News reports. But “the study found that over the past 30 years, the amount of heat in the warm layer has doubled.” If it reaches the surface, it could melt some of the Arctic ice pack, according to the research team from Yale University and Woods Hole Oceanographic Institution.
- Concise headlines. Original content. Timely news and views from a select group of opinion leaders. Special extras.
- Everything you need, nothing you don’t.
- The Weekender: The climate news you need.
“Warm water typically floats, because it’s lighter than cold water,” CBC explains. “In the basin, the warm water doesn’t float because it’s insulated, and the saltiness makes it heavy enough to sink. The colder, fresher water sits above, near the sea ice.”
But now, “warm water is coming from the edges of the basin, places like the Northern Chukchi Sea, where every summer sea ice melts and retreats,” writes CBC Northern reporter Katie Toth. “That leaves a lot of open water exposed to the sun rays directly,” explained lead author Mary-Louise Timmermans.
“That heat isn’t going to go away,” added co-author John Toole. Eventually, “it’s going have to come up to the surface, and it’s going to impact the ice.”
Timmermans said there’s no immediate threat to the sea ice above. But if the warm layer becomes warm enough, the paper stated, the salt water could eventually stop sinking and begin mixing with the cold, fresh waters above.
“It’s really difficult to say the extent to which it’s happening now,” Timmermans told CBC. “That influence may increase going forward.”
The Independent reports that the trapped warm water could have the potential to eventually melt the entire Arctic ice pack, noting that the rate of warming across the region is twice the global average.