Blog
Save
Email
Print
ShareTides are the cyclic rising and falling of Earth's ocean surface caused by the tidal forces of the Moon and the Sun acting on the Earth.
See also:
Tides cause changes in the depth of the sea, and also produce oscillating currents known as tidal streams, making prediction of tides important for coastal navigation.
The strip of seashore that is submerged at high tide and exposed at low tide, the intertidal zone, is an important ecological product of ocean tides. The changing tide produced at a given location on the Earth is the result of the changing positions of the Moon and Sun relative to the Earth coupled with the effects of the rotation of the Earth and the local bathymetry (the underwater equivalent to topography or terrain).
Though the gravitational force exerted by the Sun on the Earth is almost 200 times stronger than that exerted by the Moon, the tidal force produced by the Moon is about twice as strong as that produced by the Sun.
The reason for this is that the tidal force is related not to the strength of a gravitational field, but to its gradient.
The field gradient decreases with distance from the source more rapidly than does the field strength; as the Sun is about 400 times further from the Earth than is the Moon, the gradient of the Sun's field, and thus the tidal force produced by the Sun, is weaker.
For more information about the topic Tide, read the full article at Wikipedia.org, or see the following related articles:
Tide pool — Tide pools (also tidal pools or rock pools) are rocky pools by the ocean that are filled with seawater. Tide pools can either be small and shallow or ... > read more
Sea level — Mean sea level (MSL) is the average (mean) height of the sea, with reference to a suitable reference surface. Defining the reference level, however, ... > read more
Estuary — An estuary is a semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. ... > read more
Shift of equinox — The precession of the equinoxes refers to the precession of Earth's axis of rotation with respect to inertial space. The precession of the equinoxes ... > read more
Quicksand — Quicksand is loose, water-logged soil that yields easily to weight or pressure. It can be formed when sand, silt, clay, or other grainy soil is ... > read more
Levee — A levee, floodbank or stopbank is a natural or artificial embankment or dike, usually earthen, which parallels the course of a river. The main ... > read more
Ocean current — An ocean current is any more or less permanent or continuous, directed movement of ocean water that flows in one of the Earth's oceans. The currents ... > read more
Ocean surface wave — Ocean surface waves are surface waves that occur at the surface of an ocean. They usually result from distant winds or geologic effects and may ... > read more
Solar radiation — Solar radiation is radiant energy emitted by the sun, particularly electromagnetic energy. About half of the radiation is in the visible short-wave ... > read more
Algal bloom — An algal bloom or marine bloom or water bloom is a rapid increase in the population of algae in an aquatic system. Algal blooms may occur in ... > read moreRecommend this page on Facebook, Twitter,
and Google +1:
Other bookmarking and sharing tools:
more 