Earth Processes Part 4: Coriolis Effect, Tides, and

Seasons

Coriolis Effect/Force

•As air begins flowing from high to low pressure, the Earth rotates under it, making the wind follow a curved path.

•Winds follow curved paths across the Earth.

•In the Northern Hemisphere, the wind turns to the right.…clockwise.

•In the Southern Hemisphere, it turns to the left.…counterclockwise.

•The Coriolis force is zero at the equator.

MYTH!!!

Ocean Tides.•Tides are the periodic rise and fall of the ocean waters. They are caused by the gravitational pulls of the Moon and rotation of the Earth.

•As the Earth rotates, the moon's gravitational attraction is greatest on side closest to moon and opposite side….creating “tidal bulges”.

•As the Earth rotates, the tidal bulges move across the oceans causing two daily high and two daily low tides. (go to internet!!!)

Rotations

•It takes one day (24 hours) for the Earth to make full rotation on its own axis.

•It takes 1 year for the Earth to revolve one time around Sun.

•It takes 28 days for the Moon to rotate once around the Earth.

Tides caused by the Moon. Note that the length of the arrows is proportional to the strength of gravitational force.

Spring Tides - Strong tides occur when the Moon and sun line up. Happen in full or new moon only.

Neap tides - Weak tides when Sun, Earth, and Moon are at right angles.

Intertidal Zone

• The intertidal area (also called the littoral zone) is where the land and sea meet, between the high and low tide zones.

• This complex marine ecosystem is found along coastlines worldwide. It is rich in nutrients and oxygen and is home to a variety of organisms.

Seasons of Earth

•Seasons are caused by tilt of the Earth.

•The seasons have nothing to do with how far the Earth is from the Sun.

•Tilt = 23.5 degrees

Equator always the hottest.

When northern hemisphere tilts towards sun (left) = summer

Tilts away from sun = winter

Notice that when the Northern hemisphere is pointed toward the Sun, the Southern hemisphere is pointed away, and vice versa. So when it is summer in the north, it is winter in the south and vice versa