An area or expanse of floating ice that is not fast—not anchored to the shore or to any grounded iceberg, glacier face, or ice wall—is called a floe. “Once embedded within the pack, a floe enjoys a collective identity,” writes Stephen J. Pyne in his book The Ice, but until then, floes are solitary creatures. Floes gathered together in unconsolidated pack ice create fantastic patterns of many-sided, blue-tinged shapes floating in dark water. From above they seem like icy puzzle pieces on a liquid table. Floes are classified according to an international system of reference: giant (over 10 km), vast (2 to 10 km), big (500 m to 2 km), medium (100 to 500 m), and small (20 to 100 m). Even smaller than “small” are ice cakes. The largest of these floes, then, can be fifty miles or much more across, while the smallest are no more than six feet wide. After that, such small floes are generally called brash ice.

Gretchen Legler