sea ice
ice formed from frozen seawater
pack ice
all sea ice other than fast ice; thus, sea ice that is capable of substantial motion and deformation
fast ice
sea ice that is immobile due to its attachment to a coast, usually extending offshore to about the 20-m isobath
grease ice
thin, soupy layer of frazil crystals clumped together, which makes the ocean surface resemble an oil slick
Arctic ice pack
sea ice cover of the Arctic Ocean and its vicinity