We calculate the actual speed of the tsunami by measuring the water depth at a point in time when the tsunami passes by. A tsunami's ability to maintain speed is directly influenced by the depth of the water. A tsunami moves faster in deeper water and slower in shallower water. So unlike a normal wave, the driving energy of a tsunami moves through the water as opposed to on top of it. Therefore, as a tsunami moves though deep water at hundreds of miles an hour, it is barely noticeable above the waterline. A tsunami is typically no more than 3 feet (1 meter) high until it gets close to shore. Once a tsunami gets close to shore, it takes its more recognizable and deadly form.
Adult head lice can live for approximately 24 hours away from a host, according to the Centers for Disease Control. Nymphs, or young head lice, can live for only several hours away from a host. Lice eggs are less dependent on a host, and they can live for up to one week without a host. Continue Reading.
A hair louse can live on a personâs head for up to 30 days. They are not able to survive more than 24 hours off the head. A nit, separated from the head, will die. It needs the warmth of the body to incubate (much like a chicken sitting on an egg).