crack of ice meaning in English

冰缝

I happened to be just one mile away from this iceberg when we heard the cracking of ice and it seemed to come from that one iceberg alone . then its sharp peaks rising white in the sky , looked like it was starting to lean over . we all went to the rail of our ship and watched as it leaned a little more , then a little more , until it tipped completely upside down , and there was the bottom of the iceberg , all green
他说：发生了一个现象，我刚巧在一英里外，听到一声雪崩巨响，似乎是来自那座雪山的，它雪白的山峰高耸入云，但看来它开始倒向一边我们都站到船的围栏旁，从一英里外观看这情境，它越来越倾斜，直到它的顶峰倒过来。