Abstract - Ken Brink

Tides are the most predictable of all ocean phenomena because they are forced by the sun’s and moon’s gravitational attraction. These heavenly bodies both have well-known periodicities that, in turn, lead to tidal regularity. A combination of centrifugal and gravitational forces acts on the ocean, atmosphere and even Earth’s crust to drive tidal motions having periodicities that reflect combinations of regular periods, such as Earth’s daily rotation combined with the moon’s rotation around Earth. Ocean tides are complicated by the complex geometry of the ocean basins, so that there are “quiet” areas, along with resonant “hot spots” such as the Gulf of Maine/Bay of Fundy system. Tidal currents dissipate, leading to extraction of energy from the rotational motion of the moon around Earth, for example. Ultimately, this type of drag changes the length of the day and of the lunar month. The heat created by extreme tidal dissipation is what keeps the moon Europa’s ocean partly liquid as it orbits Jupiter. Even more extreme tidal forces can be found as objects revolve around black holes, leading to the destruction of the orbiting bodies. ... See more