Science / Weather / Tsunami: An ocean wave with a long period that is formed by an underwater earthquake or landslide, or volcanic eruption. It may travel unnoticed across the ocean for thousands of miles from its point of origin and builds up to great heights over shallower water. Also known as a seismic sea wave, and incorrectly, as a tidal wave.
Science / Tides and Currents / Long Period Waves: Forced or free waves whose lengths are much longer than the water depth. See tidal wave and tsunami. MORE
Science / Tides and Currents / National Water Level Observation Network (NWLON): The network of tide and water level stations operated by the National Ocean Service along the marine and Great Lakes coasts and islands of the United States. The NWLON is composed of the primary and s MORE