Many synthetic organic compounds such as plastic polymers, and a few natural ones, contain halogen atoms; these are known as halogenated compounds or organic halides. Chlorine is by far the most abundant of the halogens in seawater, and the only one needed in relatively large amounts (as chloride ions) by humans.
What is the difference between a tsunami and a tidal wave? Although both are sea waves, a tsunami and a tidal wave are two different and unrelated phenomena. A tidal wave is the wave motion of the tides. A tidal wave is a shallow water wave caused by the gravitational interactions between the Sun, Moon, and Earth.
Seismic sea wave. The term seismic sea wave also is used to refer to the phenomenon, because the waves most often are generated by seismic activity such as earthquakes. Prior to the rise of the use of the term tsunami in English-speaking countries, scientists generally encouraged the use of the term seismic sea wave rather than tidal wave.