Deep ocean currents can be caused mostly by?

A. Coriolis effect B. Upwelling C. Surface currents going

deeperD. Differences in density

Friday, February 1st

Ocean Test will be Tuesday

February 5th!!!

ATTENTION

Review your notes and review on:

Tides, Waves, Currents

Today’s Mission

#1 Waves What causes

waves?

Where do you find most waves?

Waves in the news!http://

abcnews.go.com/WNT/video/daredevil-surfer-tackles-largest-wave-18349457

Wind causes most waves

Describing a wave

Wave SIZEDepends on 3 Things

1. Strength of wind

2. Length of time wind blows

3. Distance over which the wind blows

Do waves carry WATER to the shore?

NO!The water does not

move toward the shore. If it did all the water would be on the shore!

So, What moves toward the shore?

The ENERGY!The energy moves toward the shore, but the water itself remains where it was.

Does the water move at ALL?

YES! How?The water particles move in a circular motion.

The deeper you go the smaller the circles.

Below a certain depth, the water does not move at all!EX. Does a submarine get tossed around during a storm? No!

SandbarsAs the waves slow down, they deposit the sand on the shallow, underwater slope. This creates a SANDBAR

RIP CURRENTSA rush of water that flows rapidly back to sea through a narrow opening (water breaks through a sandbar)

SWIM PARALLEL

A tsunami (pronounced soo-NAA-mee) is a series of

waves (called a "wave train") generated in a body of water by a pulsating or abrupt disturbance that vertically displaces the

water column.

Tsunami's are also mistakenly referred to as tidal waves as

they often resemble a tide that keeps rising, rather than cresting waves when they reach shore.

However, as they are not actually related to tides the term may be misleading, and its use is discouraged by scientists.

Anthony Liekens 15:30, 28 Dec 2004 (UTC)

Tsunamis are created when:•Seafloor quickly changes shape

•Water is displaced

•Waves are formed as the displaced water mass, which is affected gravity, tries to move back

Characteristics

Move at high speedsCan travel enormous distances with little energy loss

Can cause damage thousands of miles from its origin

May be several hours between its creation and its impact on the coast

#2 TidesWhat causes

Tides?

What’s the difference

between Neap and Spring

tides?

Tides are caused by the

moon and sun’s gravity pulling on the Earth’s water

Earth, Sun and Moon

                                            

                

How many high tides and low tides do

we have each day?

If you are at the beach and high tide is at 6:00am, about

what time would low tide be?

When would the next high

tide be?

Watch carefully!

This is a view from above the North Pole.

This is what is happening at the beach!

                                                                                                     

                           

As the moon pulls on the Earth’s water, it rises and falls.

Have you had a “tide” experience at the beach?

The Math: There are 2 high tides and 2 low tides every 24 hours This means the tide goes from high to low in about 6

hours. This also means that every there is a 12 hour time

period between each high and low tide

Time Chart: 7:00 am high tide________ low Tide ________ high tide ________ low tide

Spring tides

Are tides that are especially high or low during a 24 hour period.

They are caused by the earth, moon, and sun lining up in a straight line and the pull on the oceans is especially strong.

Neap tides

Tides that show very little change between high and low tide during a 24 hour period.

They are caused by the earth, moon, and sun forming a right angle and the pull on the oceans is weak

Spring

NEAP

#3 currentsWhat causes

surface currents?

What causes deep currents?

Currents – an ocean current is a “river” of moving water with the ocean.

The water in the current has the same properties and does not mix much with the rest of the ocean.

All ocean currents flow in predicable patterns

http://www.youtube.com/watch?v=JpV7NIJTxD0

Surface currents, like waves, are driven and determined by wind and the Coriolis effect

Coriolis effect – the apparent curving of the path of a moving object from an otherwise straight path due to the Earth’s rotation.

Northern hemisphere: clockwise

Southern hemisphere: Counter-clockwise

SurfaceCurrents

Because the Earth is spinning, the ocean water and wind trying to

travel in a straight line from one place to another gets pulled off

course.

Link to a Coriolis Effect animation part 2Link to a Coriolis Effect animation

Notice that the ball in the center of the disk is trying to roll toward the red dot. But because the disk is spinning under the ball, it never

makes it to the red dot but is “deflected” to the side.

http://en.wikipedia.org

The top view is showing that the ball actually moves in a straight line.

The bottom view is showing the path the ball took across the disk.

It is a “river” of warm water in the Atlantic Ocean!

CAN YOU FIND

THE GULF STREAM?

Ocean currents can affect climate by warming or cooling the air above the current.

Example – England is warmer than it should be based on its latitude because of the Gulf Stream current coming from the southern USA.

Deep Ocean CurrentsCaused by the change of density

Temperature and salinity effects the density

Caused from the polar ice caps