Stability of ice ridge shape and self-induced oscillations of sea ice cover. Ice ridges are typical features of sea ice cover. They are formed from ice blocks under the compression and shear of ice cover along cracklike faults or along contact lines of floes. Near coastline ridges influence on the distribution of ice stresses in the vicinity of shelf constructions and stipulate stability of fast ice location. Dynamic model of single ice ridge of arbitrary shape is constructed.
Single ridge is considered as discontinuity line in continuous ice cover.
Analysis of the laws of mass, impulse and energy conservation over the discontinuity line gives possibility to find the stresses between ridged and level ice and the equations describing variations of ridge shape during buildup process. Instability of 3D ridge shape due to shear strain and ridge line twist is found. It is shown that the instability stipulates dividing of ridge on separate hills. Dynamic model of formation of several ridges between level ice floes is constructed on the basis of single ridge model. Self-induced oscillations of level ice floes under onshore permanent wind are found.