The impact of the sea ice conditions in the nearshore zone and shore ice on the wave propagation and coastal morphodynamics in polar regions on the example of south-western Spitsbergen - the analysis of processes, modeling, and prediction.

The global Warming results in the decline of shore ice and pack ice growth, and along with the increasing number of storms in autumn and winter it poses a threat to the coasts of Arctic. Considering the rising interest in polar regions’ natural resources it is expected, that the coastal areas will be used as locations for land bases. Incorporation of sea ice and shore ice effects in the models of coastal erosion will be crucial for their security. In The State of Arctic Coasts report (2010) it is concluded, that the polar coasts are the very dynamic environment that is particularly sensitive to the climate change, mostly through constant adaptation to the changing conditions, which are: retreat of the glaciers, thawing permafrost, rise in sea temperature, prolonged periods with no sea ice and increasing number of storms. The coasts of Arctic are over 30% of the global shoreline’s length. Still, their dynamics is not known enough to fully understand the processes that control them. The scientific studies describing the above are insufficient in quantity and quality. It is estimated that only 1% of the Arctic coasts have been investigated. Those investigations concern mainly the thermal abrasion of the Alaskan, Canadian and Siberian coasts rich in permafrost, which are characterized by the most rapid erosion rates, exceeding 10 m/a. In comparison, the coasts of Svalbard and other archipelagos are under-investigated, and in scientific reports they are considered relatively stable. This project has delivered the new information describing the erosion processes on the coasts of the southwestern Spitsbergen. Moreover, the state of knowledge is in constant supplementation by the monitoring data from the two bays; Isbjornhamna and Hansbukta in Hornsund fjord. These are the key locations, considering the proximity of the Polish Polar Station which concentrates the execution of the research conducted by polish scientific facilities. In the number of the project – related studies, the special attention is turned to the increase in the extreme events count, particularly in winter. This observation is important due to the fact, that the decline of the sea ice and shore ice, which both protect the coasts from the wind waves, is also observed in this period. In the studies it was noted that the drift ice plays important role in the damping of the incoming waves. This type of ice is observed mainly in the spring, when the break-up of the sea ice in the Barents Sea occurs. Therefore, the ice’s protective function does not apply for the period of winter. The measured erosion rate for the coast is 1 m/a but it is linked to single, violent storm events. In other periods, the shore can be accreted with the sediment from other parts of the coast. Considering the main direction of the propagation of the wind waves in the North Atlantic, the northern coasts of the west coast of Spitsbergen are the most sensitive to the wave-induced erosion. This phenomenon has to be considered while planning the modernization of the Polish Polar Station. Despite all the effort in reinforcing the shore, the port building and the power generators’ fuel station are in danger. The fuel station is currently circa 10 m away from the winter berm, which is 2 times closer than 7 years ago. This erosion rate is expected to increase, but even when it will remain constant, the area is threatened by an ecological disaster, if the fuel station will not be moved. The initiated monitoring along with the published results of the project should be the starting point for further research including the preparation of the extension project to investigate the sea-ice-rich areas such as the eastern coasts of Spitsbergen.

Additional Info