Is it, for instance, mostly rock and ice with a few pockets of gas, or is it a loose pile of rubble held together by gravity?

例如，是由大量的石头、冰川和少量的气体构成还是由在重力作用下聚在一起的松散的碎石堆构成。

youdao

"Big hefty chunks of ice, the size of small houses, look as though they've been thrown around like rubble -- it's like an explosion, " he said.

CNN: Massive ice shelf on verge of breakup