Iceberg
An iceberg is a mass of glacier or ice-shelf ice that has broken off and floats in water. Most of its volume lies below the waterline.
Iceberg calving: The breaking away of ice from a glacier or ice shelf, often producing icebergs. This is the detachment process that creates an iceberg.
Glacier: A persistent mass of land ice that flows under its own weight. Many icebergs begin as pieces of glaciers that reach the coast.
International Ice Patrol: A U.S. Coast Guard-led organization that monitors icebergs in the North Atlantic and warns ships. It tracks hazardous icebergs near major transatlantic shipping routes.
Titanic: A British passenger liner that sank in the North Atlantic in 1912 after striking an iceberg. The collision made iceberg hazards a central concern for North Atlantic shipping.
Buoyancy: The upward force a fluid exerts on an object immersed in it. Buoyancy keeps an iceberg afloat while most of its mass remains submerged.
Ice shelf: A floating, continuous sheet of glacial ice attached to a land ice sheet or glacier. Ice shelves can shed icebergs along their seaward edges.
Iceberg monitoring: The observation and tracking of icebergs using ships, aircraft, satellites, and models. Monitoring estimates iceberg locations, dimensions, and movement for safety and research.
B-15: A giant Antarctic iceberg that broke from the Ross Ice Shelf in 2000. Its exceptional size and long drift made it a widely studied iceberg.
Sea ice: Frozen ocean water that forms, grows, and melts at the sea surface. Unlike an iceberg, sea ice forms from seawater rather than calving from a glacier or ice shelf.
Ice sheet: A continental-scale mass of glacial ice covering extensive land areas. Ice sheets feed outlet glaciers and ice shelves that can produce icebergs.