The primary cause of tsunamis are earthquakes and seaquakes.

造成海啸主要原因是地震和海底地震。

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

它是由9.1地震引发。

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

大数海啸是由地震和断层线引，也可能由火山爆发引发。

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

威利有些晕船，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.

可能解释包括一场海震，它可能从海底释放出有毒气体， 船员们试图逃离。

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

海底地震持续时间越长、强度越大，它所引发海啸也就越强——2004年12月26日印度洋地震就是如此。