Pack ice is a unique natural phenomenon. It is observed only in the northernmost latitudes of the planet, in the Arctic region. Once this term was applied to absolutely all drifting ice, but after conducting multiple studies, the packs were allocated to a separate group. They have a number of properties that distinguish them from other types of ice. The definition of “perennial ice” is synonymous, therefore it occurs at approximately the same frequency.
Features of pack ice
Arctic researchers, sailors and travelers who have ever visited the northern latitudes are well aware of what pack ice is. This phenomenon brings a lot of trouble to the conquerors of the north.
These ice drift in the ocean, their mass is huge, and the density is very high. Accidental collision can cause considerable harm even to the most modern vessel. Packed ices differ from ordinary ones in their properties. According to experts, the pack is formed from sea water, its thickness exceeds 3 meters. It is denser than ordinary ice due to the extremely low salt content.
The process of forming pack ice
Ice forms in the northern latitudes at low temperatures. When sea water freezes, a desalination process occurs, thawed water always has a lower salinity level than the source. This is a distinctive feature of packs that undergo several freezing and thawing processes.
Sea water freezes, icebergs and large ice floes form. Subsequently, smaller ice floes detach from large ice massifs, many of which later turn into packs. They are not characterized by any common signs in form. The most diverse packs are found: from flat ice floes to huge blocks rising above the sea surface.
Researchers have found that, before embarking on a voyage, pack ice undergoes at least 2 annual freezing and freezing cycles. This is due to its high density and low salinity. The fact is that when thawing and re-freezing water, salt is melted into the ocean. Mariners know that old pack ice is even suitable for fresh water, where you can cook food.
