The primary cause of tsunamis are earthquakes and seaquakes.

造成海啸的主要地震和海底地震。

It was triggered by a seaquake measuring 9.1 on the Richter scale.

它由里氏9.1级的地震引发的。

Most tsunamis are generated by seaquakes and fault lines, but they can also be triggered by volcanic eruptions.

大数海啸由地震和断层线引起的，但也可能由火山爆发引发。

Willy was seasick and could not get used to the seaquake.

威利有，他不适应海啸。

Possible explanations include a seaquake, which could have released poisonous gas from the sea floor, which the crew tried to escape.

可能的解释包括一场海震，它可能从海底释放出有毒气体， 员们试图逃离。

The longer and stronger an undersea quake, the more powerful the tsunami it triggers — as in the Indian Ocean seaquake of December 26,2004.

海底地震持续的时间越长、强度越大，它所引发的海啸也就越强——2004年12月26日的印度洋地震就如此。