Ice Shelf

ice · Antarctica · glaciers · floating

Floating frozen platform. An ice shelf is a huge slab of glacial ice that floats on the ocean, kind of like a gigantic ice cube in water. It stays connected to glaciers and ice sheets on land that keep feeding it new ice.

Born from thick ice. Ice shelves only form in places where glaciers get so thick and heavy that they push their way down to the coast. When the ice reaches the ocean, it's still so thick that it doesn't immediately sink, so it spreads out flat and floats.

Three special boundaries. An ice shelf has important dividing lines: the grounding line (where it stops touching the ocean floor and starts floating), the calving front (where it meets open ocean), and the glacier above feeding it fresh ice from inland.

Fed by multiple glaciers. Most ice shelves don't come from just one glacier. Instead, several tributary glaciers up in the mountains funnel their ice down into the same shelf, all combining their frozen rivers together.