A Disappearing Glacier in Alaska

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A glacier disappearing

Over the last three decades, the Columbia tidewater glacier in the Chugach Mountains of Alaska has retreated more than 20 km and lost about half of its total thickness and volume. The changing climate is thought to have nudged it into retreat in the 1980s, resulting in its end – or terminus – breaking off. The terminus had previously been supported by a moraine, which is an accumulation of sediment and rock that served as an underwater barrier, helping to keep the glacier stable and insulate it from seawater. With this barrier gone, glacial dynamics took over and it began to flow to the ocean faster, calving large icebergs into the Sound. As this satellite image shows, many icebergs can be seen in the Sound. This one glacier accounts for nearly half of the ice loss in the Chugach Mountains. However, researchers believe that the Columbia Glacier will stabilise again – probably in a few years – once its terminus retreats into shallower water and it regains traction, which should slow the rate of iceberg calving.

Source and Credits: contains modified Copernicus Sentinel data (2017), processed by ESA, CC BY-SA 3.0 IGO and NASA/USGS via ESA Earth on Instagram

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I am a Chartered Environmentalist from the Royal Society for the Environment, UK and co-owner of DoLocal Digital Marketing Agency Ltd, with a Master of Environmental Management from Yale University, an MBA in Finance, and a Bachelor of Science in Physics and Mathematics. I am passionate about science, history and environment and love to create content on these topics.