A zone directly adjacent to the waterline, where only coast related activities take place. Usually this is a strip of some 100 m wide. In this strip, coastal defense activities take place. In this strip often there may be restrictions to land use.

The transition zone where the land meets water; the region that is directly influenced by marine hydrodynamic processes. Extends offshore to the continental shelf break and onshore to the first major change in topography above the reach of major storm waves.

The integrated and general development of the coastal zone. Coastal Zone Management is not restricted to coastal defense works, but includes also coastal development in economical, ecological and social terms.

The line that forms the boundary between the coast and the shore. Commonly referred to as the line that forms the boundary between the land and the water (especially the water of a sea or ocean, also called the shoreline).

The zone bordering a continent extending from the line of permanent immersion to the depth, usually about 100 m to 200 m, where there is a marked or rather steep descent toward the great depths of the ocean. The region of the oceanic bottom that extends outward from the shoreline, with an average slope of less than 1:100, to a line where the gradient begins to exceed 1:40 (the continental slope).

The declivity from the offshore border of the continental shelf to oceanic depths. It is characterized by a marked increase in slope.

A coral-algal mound or ridge of in-place coral colonies and skeletal fragments, carbonate sand, and organically-secreted calcium carbonate. A coral reef is built up around a wave-resistant framework, usually of older coral colonies. Extensive limestone structures built largely by corals. They occur primarily in shallow tropical and provide habitat for a large variety of other marine life forms.

The length of a wave along its crest. Sometimes called crest width.

An instrument for the early detection, measurement, and real-time reporting of tsunamis in the open ocean.

Time between the maximum level arrival time and the arrival time of the first wave.

Time of tsunami arrival at some fixed location, as estimated from modeling the speed and refraction of the tsunami waves as they travel from the source. ETA is estimated with very good precision if the bathymetry and source are well known (less than a couple of minutes).

A reference mark on a structure or natural object, indicating the maximum stage of tide or flood.

A tsunami identified as having occurred through eyewitness or instrumental observation within the historical record.

An intense tropical cyclone in which winds tend to spiral inward toward a core of low pressure, with maximum surface wind velocities that equal or exceed 33.5 m/sec (75 mph or 65 knots) for several minutes or longer at some points. Tropical storm is the term applied if maximum winds are less than 33.5 m/sec but greater than a whole gale (63 mph or 55 knots). Term is used in the Atlantic, Gulf of Mexico, and eastern Pacific.

Time of the first minimum of the tsunami waves.