2.3 tides and currents Flashcards
Tide
The periodic rise and fall of the surface of the ocean resulting from the gravitational pull of the Moon and the Sun
Semi-diurnal
Occurring twice daily
Diurnal
Occurring daily
Tidal Range
The difference in height between the high-tide mark and the low-tide mark over the course of a day; also called the tidal amplitude
Tidal Surge
The coastal flooding of an abnormally high seawater level associated with low pressure weather systems; also called storm surge
Spring Tide
A tide that occurs when the Sun and Moon are aligned, causing the largest tidal range
Neap Tide
A tide that occurs when the Moon and Sun are at right angles from each other, causing the smallest tidal range
Current
A continuous physical movement of water caused by wind or density
Coriolis Effect
A force that results from the Earth’s rotation that causes objects or particles in motion to deflect to the right in the Northern Hemisphere and to the left in the Southern Hemisphere
Thermohaline Circulation
Large-scale ocean circulation caused by density differences due to temperature and salinity changes in the world’s ocean
Global Ocean Conveyor Belt
Constantly moving systems of deep-ocean water driven by thermohaline circulation
Downwelling
The downward movement of water in the sea due to density differences
Upwelling
The movement of cold, nutrient-rich water from deep in the ocean to the surface
El Niño
A warm current that develops off the coast of Ecuador around December, which can cause widespread death within local food chains
La Niña
A cold current that develops off the coast of Ecuador and spreads across the Pacific, reducing sea surface temperatures for extended periods of time
