In this week’s Video of the Week, Australian Geographic photographer and conservationist Chris Bray captures a spectacular ice fall at Alaska’s Chenega Glacier in the Fall of 2019. “Wait for the end, it all comes down!” said Bray in his Instagram caption. “It was so explosively powerful we could feel it in our chests!” In the slow motion video, startled seabirds can be seen evacuating their forage zone at the glacier’s face.
Chenega is a 12-mile (19-kilometer) long tidewater glacier in Alaska’s Prince William Sound. A study which looked at the terminus position of 50 Alaska tidewater glaciers from 1948-2012 found Chenega was the lone glacier to not advance or retreat significantly. It is not clear whether the glacier has begun to retreat in the eight years after the study was completed, but once retreat begins it’s hard to stop. “The retreat phase of a tidewater glacier can be triggered by changes in climate,” the study’s authors wrote. “Once retreat is initiated, the glacier’s behavior is only weakly influenced by climate and geometry becomes a primary driver of behavior.”
An April 2019 study published in the journal Nature found that glacier melt is occurring more rapidly than previously thought and accounts for 25-30 percent of observed sea level rise since 1961, with Alaskan glaciers being the largest contributors. “Awesome to witness but sad to see more and more rock exposed every year at my favorite glacier as the face retreats more and more,” Bray said, adding the tag #globalwarming.