When the processes of loss and addition are approximately in balance, the glacier front stays in about the same place.
The additional heat weakens the ice tongue and promotes cracking and calving from the glacier front.
Pack ice in the fjords was so thick that even the Arctic Sunrise couldn't penetrate to the glacier fronts. Fortunately, the ship had another way to give the researchers access to the inner reaches of the fjords--a helicopter and a pilot with experience in the Arctic.
The scientists weren't able to take measurements right next to the glacier fronts, but the warm water mass showed no dissipation from the fjord's mouth to within a few kilometers of the front.
Both species traditionally hunt for food in areas with sea ice and particularly at so-called tidal glacier fronts, where glaciers meet the ocean.
The data showed that two decades ago, both species spent around half their time foraging at glacier fronts and eating a diet dominated by polar cod.
But ringed seals now spend "significantly higher proportions of time near tidal glacier fronts" while the white whales had the opposite response and had moved elsewhere to look for food.
"Tidal glacier fronts appear to be serving as Arctic 'refugia' for RS (ringed seals), explaining why this species has increased the amount of time spent near glaciers," the study published Wednesday in the Royal Society Biology Letters journal said.
White whales meanwhile now "have larger home ranges and spent less time near glacier fronts and more time in the center of fjords".
"What made OMG unique compared to other campaigns is that they got right into the fjords, as close as possible to the glacier fronts
. That's a big help for bedrock mapping," he added.
Jacobs had never witnessed upwelling first hand, but colleagues had described something similar in the fjords of Greenland, where summer runoff and melting glacier fronts
can also drive buoyant plumes to the sea surface.