An extensive dome-shaped or platelike perennial cover of ice and snow that spreads out from a center and covers a large area,especially of land.

• 冰冠，冰帽一种大面积的圆丘形或盘子形的长年雪盖或冰盖，它从中心向外扩展，覆盖很大的一块区域，尤其是陆地。