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 a wave, or series of waves, caused by the vertical displacement of a column of water. This can be generated by earthquakes below the sea floor and violent volcanic eruptions above it, landslides above or below water or meteorite impacts into the sea.pecies Invasion. Tsunamis can carry massive amounts of debris from one side of the ocean to another. A concrete block from Misawa, Japan took 15 months to cross the Pacific Ocean and crash into the Oregon coast. Algae and other organisms attached to this debris survived the ocean crossing.