After lying dormant for hundreds of years, a seaside volcano erupts, splitting its cinder cone, plunging hundreds of tons of material into the sea. The splash from the debris impact flies hundreds of meters into the air and then falls back to the sea as nearly semi-circular water waves begin to radiate away from the volcano. Within minutes, the nearby coastal towns are obliterated by the towering walls of water that wash over them. Hours later the waves arrive at distant shorelines that surround the sea. These waves have evolved in form, being far different than those near the volcano due to radial spreading, frequency dispersion, and nonlinear effects. Their destructive nature has been reduced over the thousands of kilometers the waves have traveled; nonetheless, the shallow coastal water depths have caused the incoming waves to slow, increasing in height sufficient to overrun the shoreline, overtop breakwaters, and to smash into the coastal communities, killing thousands.