英语语法分析

Yellowstone obviously was of this second type, but Christiansen couldn't find the caldera anywhere.

黄石公园显然属于第二种类型，但是克里斯蒂安森就是找不到这个火山口。

These volcanoes are so explosive that they burst open in a single big crack, leaving behind a vast hole, the caldera.

这些火山具有极强的爆发性，以至于在它们从一条大的裂缝中喷涌而出，留下了一个巨大的洞，也就是火山口。

The caldera was enlarged by later paroxysmal eruptions ending in the one of AD 79.

破火山口因后来的阵发性爆发而扩大，最终于公元79年一次爆发。