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.
 A tsunami is not a single wave but a series of waves, also known as a wave train. The first wave in a tsunami is not necessarily the most destructive. Tsunamis are not tidal waves. Tsunami waves can be very long (as much as 60 miles, or 100 kilometers) and be as far as one hour apart. They are able to cross entire oceans without great loss of energy.A tsunami is not a single wave but a series of waves, also known as a wave train. The first wave in a tsunami is not necessarily the most destructive. Tsunamis are not tidal waves.