Video shows an Alaska glacier retreating 20 km over 48 years

NASA's Goddard Space Flight Center uploaded a video showing time-lapse of changes in the glaciers in Alaska in the past 48 years. The Columbia Glacier's front began retreating rapidly in the mid-1980s and by 2019, it was 20 km upstream, NASA said. The Hubbard Glacier has advanced 5 km, however, a 2019 image shows a large indentation in the glacier.