Icebergs are large floating pieces of ice found in oceans and lakes. Icebergs form when land-based ice breaks off, or calves, from glaciers, ice shelves, or a larger iceberg. Most icebergs form near Antarctica and in the the North Atlantic Ocean near Greenland.
An iceberg the size of Greater London recently broke off the from Amery Ice Shelf in Antarctica. With an area of 1,600 square kilometers (km), researchers estimate the iceberg to be 30 km wide and 60 km long. Named D23, the iceberg is also estimated to weigh 300 billion tons. The iceberg calved sometime between September 22 and 25, 2019. Scientists believe D23 is the biggest calving of the Amery Ice Shelf in 50 years.
The European Space Agency’s satellite Copernicus Sentinel-1 captured the event in two separate satellite images of the area: