Waves and Tides

Wave Crest

A crest is the point on a wave with the maximum value or upward displacement within a cycle.

Wave Trough

A trough is the opposite of a crest, so the minimum or lowest point in a cycle.

Diurnal Tides

An area has a semidiurnal tidal cycle if it experiences two high and two low tides of approximately equal size every lunar day.

Wave Period

The time required for two successive wave crests to pass a fixed point, or the time for a single wave crest to travel a distance equal to the length of the wave.

Semidiurnal Tides

it experiences two high and two low tides of approximately equal size every lunar day.

Mixed Semidiurnal Tides

observed at the equator at all times, most locations north or south of the equator experience two unequal high tides and two unequal low tides per tidal day; this is called a mixed tide and the difference in height between successive high (or low) tides is called the diurnal inequality.

Tides

the alternate rising and falling of the sea, usually twice in each lunar day at a particular place, due to the attraction of the moon and sun.

Wavelength

the distance between successive crests of a wave, especially points in a sound wave or electromagnetic wave.

Downwelling

the downward movement of fluid, especially in the sea, the atmosphere, or deep in the earth.

Seas

the expanse of salt water that covers most of the earth's surface and surrounds its landmasses.

Surf

the mass or line of foam formed by waves breaking on a seashore or reef.

TIdal Range

the vertical difference between the high tide and the succeeding low tide.

Wave Height

the wave height of a surface wave is the difference between the elevations of a crest and a neighbouring trough.

Great Ocean Conveyor

a constantly moving system of deep-ocean circulation driven by temperature and salinity.

Tsunamis

a long high sea wave caused by an earthquake, submarine landslide, or other disturbance.

Rip Currents

a relatively strong, narrow current flowing outward from the beach through the surf zone and presenting a hazard to swimmers.

Tide Tables

a table indicating the times of high and low tides at a particular place.

Spring Tides

a tide just after a new or full moon, when there is the greatest difference between high and low water.

Neap Tides

a tide just after the first or third quarters of the moon when there is the least difference between high and low water.

Capillary Waves

a wave traveling along the phase boundary of a fluid, whose dynamics are dominated by the effects of surface tension.

Upwelling

an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water.

Rogue Waves

are large, unexpected and suddenly appearing surface waves that can be extremely dangerous, even to large ships such as ocean liners.

Wave Fetch

area of ocean or lake surface over which the wind blows in an essentially constant direction, thus generating waves.