Five great earthquakes of M9 or larger have been recorded in the past century and each was followed by a major tsunami, along with vast devastation and many deaths. These events have provided information to help mitigate the effects of future great earthquakes - including what to keep in the back of your mind if you experience strong earthquake shaking in coastal areas worldwide.
I’ve seen lots of sharks when I’ve been on snorkeling excursions in tropical waters. It always feels a bit creepy to see them – afterall, these animals are top predators! (Maybe I remember too many of Gary Larson’s “natural selection” cartoons....?)