A lead that connects two open bodies of water; ships can traverse between them through this lead; it also refers to a lead where open water is found, or a lead that has not completely frozen.
Pack ice in which the ice concentration is four-tenths to six-tenths, with many leads and polynyas, and the floes are generally not in contact with one another.
A loose grouping of dozens or hundreds of young stars distributed in a region a few light-years across. Open clusters are relatively young, typically containing many hot, highly luminous stars. They a
re located within the disk of the Galaxy, whence their older name Galactic clusters.
A pingo formed by doming of frozen ground due to freezing of injected water supplied by groundwater moving downslope through taliks to the site of the pingo, where it moves towards the surface
Is a form of localized unfrozen ground (talik) in an area of permafrost. It is open to the ground surface but enclosed to permafrost below and at its sides.
A large area of freely navigable water in which floes may be present in concentration under 1/10th; if there is no sea ice present, the area may be termed open water, even though icebergs are present.
Sea ice terminology describing a large area of freely navigable water in which ice is present, with a concentration less than 1/10. In open water no ice of land origin is present.
A large area of freely navigable water in which floes may be present in concentrations under 1/10th. If there is no sea ice present the area may be termed open water, even though icebergs are present.