Tides

tides

a type of wave

wave

energy moving through a medium

describe a tide

1. Periodic rising and falling of the ocean surface
2. Occurs over a given time interval
3. Observable around edges of land (ocean shoreline)
4. Predictable

variable (capable of change)

Tides can be highly ___.

tidal amplitude

difference in water height between high and low tide levels

Jamaica, Mediterranean

Example of extreme low tide; less than 3 feet

Bay of Fundy

Example of extreme high tide; 50 feet

Coastal California

10-15 ft. max.

2 cause of tides

1. Gravitational force
2. Centrifugal force

moon/sun

The gravitational force of the ___ and ___ cause tides.

moon

The force of the ___ has the greatest pull on tides.

solar year

365 and a forth days; the time it takes the earth to complete one orbit around the sun

solar day

24 hours; the time it takes the sun to reappear in the same position in the sky

tilted

The earth is ___ at a 23.5 degree angle.

lunar day

24 hours, 50 minutes; the time it takes the moon to reappear to an observer on Earth

tidal bulge

forms on the side of Earth that is closest to the moon

centrifugal force of Earth/Moon system

Because the earth and moon revolve around each other, water on Earth is drawn outward (away from Earth).

Why are there two tidal bulges?

One bulge is due to the gravitational pull of the moon, the other is due to centrifugal force

equal/opposite

The two tidal bulges are ___ height, on ___ sides of Earth.

additive

Gravitational forces are ___.

waxing

To increase gradually in size. The illuminated part of the moon is getting bigger.

waning

To decrease gradually in size. The illuminated part of the moon is getting smaller.

location

Moon's ___ affects tide height, due to the gravitational pull of the moon.

spring tide

A tide with the greatest difference between high and low tide that occurs when the sun and the moon are aligned with Earth at the new moon and the full moon.

neap tide

A tide with the least difference between low and high tide that occurs when the sun and moon pull at right angles to each other at the first and third quarters of the moon.

westward

Tides move ___ as Earth rotates

stationary

Water level changes at a ___ point

eastward

Rotation of Earth ( ___ ) beneath tidal bulges

new/full

Spring tide occurs when the moon is at ___ and ___ .

first/third quarter

Neap tide occurs when the moon is at ___ and ___.

90 degree

The earth, sun, and moon are a ___ angle at neap tide.

180 degree (aligned)

The earth, sun, and moon are a ___ angle at spring tide.

syzygy

Alignment of Earth-Moon-Sun system in a straight line.

Quadrature

Earth-Moon-Sun system at right angles