This paper presents studies of wave propagation across a crack in an ice sheet. We consider a crack between two ice sheets that are infinitely stretching to either side. The theoretical model of the ice sheet assumes that thickness, mass density and Young's modulus to be constant. This model is often used study the dynamics of ice sheets with fairly homogeneous appearance. Such ice sheets are formed around the coast of Antarctica during the winter. In this paper we focus on the relatively long and straight cracks in the ice sheets. These crack have variety of physical properties depending on how they are formed, such as partially frozen slosh or solidly re-frozen crack. The mechanism of wave propagation across such cracks are not well understood. Wave propagation into the ice field plays an important roll how the marginal ice zone is broken up every year. There have been only simple theoretical models for the transitions in ice sheets, such as open gap or abrupt thickness changes.