Condense 48 years into six seconds, and Alaska’s glaciers move at a pace that’s anything but glacial. The rivers of ice flow and surge and shift and retreat, and time-lapse videos created from decades of satellite images track the changes over time.
The videos can help researchers study how glaciers behave over time, which in turn lets them forecast what will happen in a warming climate. Mark Fahnestock, a glaciologist at the University of Alaska Fairbanks, created these time-lapse videos for each glacier in Alaska and the Yukon, using images from the NASA/USGS Landsat satellites. He painstakingly searched for one cloud-free, late-summer satellite image for each year, going back to 1972 when the first Landsat satellite launched (Landsat 9 is slated to launch in 2021).
“When you play these movies,” Fahnestock said, “you get a sense of how dynamic these systems are and how unsteady the ice flow is.”