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.
Eggs hatch after 5 to 10 days. Young head lice (called nymphs) are mobile and molt three times, developing into mature adults in about three weeks. Adults can live for about four weeks but do not lay eggs until after seven days. Head lice do not survive off a host for more than one or two days. Head lice do not jump or fly. They can however move from an infested person to another person during play or other close contact. Head lice may also spread when an infested child shares combs, brushes, scarves, clothing, hats, towels or similar items.