TheTsunami Countdown by Boyd Morrison

Kai Tanaka works for the Pacific Tsunami Warning Centre in Honolulu.  Kai is the first person to identify the possible imminent threat of a Mega Tsunami hitting Hawaii in under an hour.  Kai must make the decision whether or not to raise the alarm - if he's wrong his job is at risk, but if he is right he has just one hour to save not only his family but the people of Hawaii too.

If you enjoy natural disaster stories this is a gripping read from start to finish.