24-hour daylight melts the ice from above, and ocean swells stress the ice from beneath.

全日不休的阳光融化了表层的冰海，浪不停地在冰下鼓动着。

They were abundantly familiar with trade wind-generated ocean swells, which typically flow northeast or southeast.

他们非常熟悉信风引起的海浪，这些海浪通常向东北或东南方向流动。