Landfast

Landfast is an adjective meaning firmly attached to land or secured to shore rather than floating or freely movable. The term derives from land and fast, an old sense of “firmly fixed.” In general usage, it can describe objects, structures, or installations anchored to the ground or coastline, or used metaphorically for ideas or arrangements that are fixed in place.

In polar science, landfast often appears in the compound landfast ice. This refers to sea ice that is anchored to the coastline, shallow seabed, or fixed underwater features, preventing it from drifting with winds and currents. Landfast ice forms when newly formed ice bonds to the shore or to bottom features and is typically more stable than drifting pack ice, persisting for weeks or months through the winter before breaking up as temperatures rise.

Geographically, landfast ice occurs along various Arctic and sub-Arctic coastlines and in some sectors of Antarctica. Its presence affects coastal navigation, sediment and ecological dynamics, and human activities such as Indigenous transit and resource operations. The extent of landfast ice is highly variable year to year and is influenced by tides, currents, and climatic conditions.

Beyond its scientific usage, landfast also functions as a general descriptor for anything fixed to land rather than floating. It is used in dictionaries and encyclopedic writing to convey the contrast between land-fixed and waterborne attachments.