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.
Reports from Sri Lanka after Sunday's tsunami say that despite the enormous number of human casualtiesâ116,000 deaths and rising, at last countâmany animals seem to have survived the tidal wave unscathed. second early-warning sign the animals might have sensed is ground vibration. In addition to spawning the tsunamis, Sunday's quake generated massive vibrational waves that spread out from the epicenter on the floor of the Indian Ocean's Bay of Bengal and traveled through the surface of the Earth.