Multiyear Fast Ice along the Taymyr Peninsula, Siberia
DOI:
https://doi.org/10.14430/arctic1260Keywords:
Barrier islands, Climate change, Cores, Fast ice, Formation, Ice shelves, Isotopes, Lagoons, Ocean waves, River discharges, Salinity, Satellite photography, Sea ice, Sea level, Sediment transport, Spits (Geography), Laptevykh More, Taymyr, Poluostrov, waters, Russian FederationAbstract
A 20 km wide zone of fast ice, reaching offshore to the 20 m isobath and sealing off coastal embayments along the Taymyr Peninsula, survived until at least 23 November 1993, becoming multiyear land-fast sea ice (MLSI). Barrier islands show characteristic recurved spits indicating dominant southeastward direction of longshore transport in intermittent years. At the time of observation, the fast ice was undisturbed, only heaving vertically with tides, protecting the coastal zone from wave reworking. The 1 to 2 m thick ice cover affects light and oxygen, creating profound effects on marine life in the zone. A herd of walrus, in other summers reported to haul out on local beaches, was displaced by the fast ice. We saw no evidence for sediment loading of the ice by rivers or eolian deposition on ice. MLSI is considered an incipient ice shelf, which could grow in thickness and strength in successive winters. Salinity and delta 18O profiles in ice cores from some smaller areas of MLSI provide a record of environmental conditions during the first year of ice growth, such as local hydrography and contribution of congealed snow to the solid fast ice. On ice charts we found no record of waxing and waning MLSI in the area, and do not know whether the observed ice survived the next summer. Since arctic ice shelves have developed from MLSI in the past, the observed phenomenon permits a view of how transitions from interglacial to full glacial conditions can begin.
Key words: multiyear land-fast sea ice, incipient ice shelves, sediment entrainment, interglacial/glacial transition, Siberia, Laptev Sea
