For more, visit TIME Health. 1  Treating migraines effectively might have gotten a lot easier, according to a new study published this month. 2  Researchers at the Albany Medical Center claim that a new innovative treatment offers chronic migraine sufferers prolonged relief from the debilitating headaches.
That's very fast and it's all because of how deep the water is (thousands of feet) and how much energy the earthquake puts into the tidal wave. So now to directly answer your question, the amount of time it takes for a tsunami to come after an earthquake occurs can be as little as 5 minutes or as long as 24 hours. It just depends on how far away the earthquake was from the coast.
A tsunami is a very long-wavelength wave of water that is generated by sudden displacement of the seafloor or disruption of any body of standing water. Tsunami are sometimes called seismic sea waves, although they can be generated by mechanisms other than earthquakes. 4.5 hours later the same tsunami reached the Hawaiian Islands after traveling at an average speed of 659 km/hr. 2  As it approached the city of Hilo on the Big Island, it slowed to about 47 km/hr (note that even the fastest human cannot run faster than about 35 km/hr) and had a run-up of 18 m above normal high tide.