Many people acted heroically in the aftermath of Hurricane Katrina. The Coast Guard, for instance, rescued some 34,000 people in New Orleans alone, and many ordinary citizens commandeered boats, offered food and shelter, and did whatever else they could to help their neighbors.
Tidal waves, or tides, are a predictable, com-mon occurrence along coastal communities, generated by forces beyond Earthâthe gravitational pull of the sun and moon. However, tsunamis are not predictable. They are often generated by earth-quakes, volcanic activity, and slope failure.idal waves, or tides, are a predictable, com-mon occurrence along coastal communities, generated by forces beyond Earthâthe gravitational pull of the sun and moon. However, tsunamis are not predictable. They are often generated by earth-quakes, volcanic activity, and slope failure.
Most tsunamis are not devastating. Scientists can and do measure tsunamis which are as small as a few centimeters. These events rarely make the news. The tsunamis which are 'devastating' are the very largest (and rarest) ones. What I think you really want to know is how far inland tsunami waves can go for the largest events with 10-1000 year recurrence intervals. (Civilization-ending events such as the Santorini eruption that destroyed the Minoan civilization are less frequent, while the biggest subduction zone earthquakes are generally one in 100-1000 years.