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.
By Amanda Briney. A tsunami is defined as a series of ocean waves that are generated by large movements or disturbances on the ocean's floor. The causes of these disturbances include volcanic eruptions, landslides and underwater explosions. Earthquakes however are the most common cause.nfortunately large tsunamis such as the one that struck Japan are not uncommon. In addition, while thousands were killed in Japan because of the twin disasters, the March 2011 tsunami is not the world's deadliest.