In summer, the fjords of Greenland are littered with ice, but in August 2023, satellites caught an odd interloper. See the thin white arc spanning the fjord in the photo above? Scientists suspect this ephemeral feature was a wave caused by a large iceberg calving off the glacier on the right. When large chunks of ice fall into the water, they can cause distinctive waves that travel out from the point of impact.
Another possible mechanism is an underwater plume. In Greenland’s fjords, such plumes are sometimes formed from freshwater melting below the glacier. When that water rises to the surface, it can push ice. (Image credit: W. Liang; via NASA Earth Observatory)