Chapter Nine Flashcards
Ebb tide
away from the shore
Spring tide
maximum tidal range due to constructive interference from solar lunar tides when the moon is full or new
Syzygy
When the Earth, Moon, Sun system is aligned
Neap
First or third quarter moon resulting in destructive tides
Quadrature
The name of the Moon when in neap tides
Declination
Angular distance of the Sun or Moon above or below Earth’s equatorial plane
Perihelion
Closest point of Earth to the sun, causing large tidal ranges
Aphelion
Farthest point of Earth to the sun, small tidal ranges
Perigee
Moon is closest to the Earth
Apogee
Moon is farthest away from the Earth
Amphidromic point
Point near the center of each cell
Cotidal lines
Lines that go from amphidromic points to location where high tide occurs simulatneously
Dirunal
one high tide, one low tide. Common in shallow inland seas. Tidal period is 24 hours and 50 minutes
Semidiurnal tidal pattern
Two high tides and two low tides. 12 hour 25 minutes tidal period
Mixed tidal
Mixed characteristics
Tidal bore
When a tide hits a river flowing the opposite away
Rotary current
Counterclockwise tide crest
Reversing current
alternating current
Flood current
When water rushes into a bay with an incoming high tide
Ebb current
When water drains out of a bay
High slack/low slack
Occurs when there is not a current at the peak of high tide or low tide
Whirlpool
Rapidly spinning body of water when two large bodies of water pass in a shallow area
Tidal power for energy
Power can only be generated at certain times of the day, initial costs high but operating costs are low, possible damage to the environment
Barycenter
Common center of mass between the Moon and the Sun, 1600 km below surface of Earth
Gravitational Force
Inversely proportional to the square of the distance between the two bodies
Zenith
greatest point of gravitational attraction, located directly above the head
Nadir
weakest point of gravitational attraction, point farthest from the moon
Centripetal Force
Force required to keep planets in their orbits is provided by the gravitational attraction between them and the Sun
Resultant forces
Mathematical differences between centripetal force and gravitational force
Tide generating forces
Occurs if the resultant force is tangential to Earth’s surface, inversely proportional to the cube of the distance between objects, creates two bulges away from the Moon and towards the Moon
Lunar bulges
toward and away from the moon
Tidal period
time between high tides
Lunar day
24 hour and 50 time period between the moon passing the same point on Earth, Earth has to catch up
Flood tide
Toward the shore
