Нагоны льда на берег: причины и последствия

Ice pushed onshore due to water movements or wind

An ice shove (also known as fast ice, an ice surge, ice push, ice heave, shoreline ice pileup, ice piling, ice thrust, ice tsunami, ice ride up, or ivu in Iñupiat) is a surge of ice from an ocean or large lake onto the shore. Ice shoves are caused by ocean currents, strong winds, or temperature differences pushing ice onto the shore,
creating piles up to 12 metres (40 feet) high. Ice shoves can be caused by temperature fluctuations, wind action, or changing water levels

When temperatures decrease, ice contracts and forms stress fractures; water then seeps into these tension cracks and freezes. When temperatures rise, the ice sheet expands. This sequence of events occurs cyclically until the total ice sheet has expanded considerably. If this ice sheet is in contact with a shoreline, it can exert considerable force on the land, causing the displacement of shore material. Studies have shown that the formation of landfast ice is starting to form later and breakup earlier in the Chukchi and Beaufort seas. More open water days increase the likelihood of destructive coastal events like ice shoves in these regions. Some have described them as 'ice tsunamis', but the phenomenon works like an iceberg. Witnesses have described the shove's sound as being like that of a train or thunder.

As described above, ice shove events occur due to deformation of land fast ice, ice that is anchored to the coast. Land fast ice grows either locally or by merging with drift ice. In the Arctic, the Transpolar Drift Stream and the Beaufort Gyre are mostly responsible for sea ice transport. In the Beaufort Gyre, surface ice transport is westward directed towards the Alaskan coast, hence being a driver in fast ice growth. The last decades a decline in Arctic ice cover has been observed. Land fast ice forms later and withdraws earlier, leading to more open water days. Open waters lead to longer wind fetch, which in turn produces more energetic waves near coastal zones, increasing fast ice erosion. The loss of sea ice directly results in a lower surface albedo and thus higher Arctic temperatures. In the case of no future reduction of carbon dioxide emission it is suggested that ice free Arctic winters are also possible, Due to complex ocean atmosphere interactions, this can lead to higher storm activity in the mid latitudes. This change could potentially give more favourable conditions for ice shove events to occur at mid latitudes, though no research has been done on this subject.