This exercise asks you to calculate travel times for a tsunami. As for travel times with automobiles, we can get time from the relationship
where the "rate" is speed. More to our purposes of calculating a travel time,
which, if we're thinking about units (and we always should be) works because
Thus the first thing you need to do is decide what controls the speed of a tsunami. Your lecture notes should have equations for speed of waves, one for deep-water waves and one for shallow-water waves. It's up to you to decide if tsunamis are deep-water waves or shallow water waves, which establishes whether you will use the deep-water-wave equation or the shallow-water-wave equation, which in turn establishes whether wavelength or depth controls the speed of the tsunami.
Contact your dutiful instructor if you have more questions!.
To the GEOL 3030 page.