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.
However, assuming they leave the scalp and do not find another host, or are not able to find their way back to their original host, a head louse will typically starve within 1 to 2 days. Nits can live off the host longer, but rarely become separated, as the female louse glues the nit to the hair strand. Nits often look like dandruff because of this, but unlike dandruff, cannot easily be brushed out of the hair.