Waves, Currents, and Tides Motion of the Ocean! Waves, Currents, and Tides

Introduction to Waves

Activating Prior Knowledge Have you ever done the “WAVE” like the one shown in the video? If so, think about these questions: How do the people move? Did the people move around the stadium?

Activating Prior Knowledge In the WAVE, the people move up and down, but the “energy” is moving around the stadium (not the people). This is just like waves in the ocean!

A wave is the movement of energy through water. What are ocean waves? A wave is the movement of energy through water.

What causes waves? Waves form from wind Waves form out in the open ocean, and travel inwards to the shore.

Tsunamis Tsunamis are giant ocean waves caused by earthquakes beneath the ocean floor As tsunamis approach the shore, the waves come closer together and grow into a mountain of water

Draw it

Tides

What are Tides? Tides are the movement of ocean water at the shore when it rises and falls throughout the day

What causes tides? The gravitational pull of the moon and sun on Earth’s water

Question- Both the sun and the Earth are pulling at the Ocean to create tides. Why do you think that the moon has a greater effect on tides even though the sun is much larger?

High Tides Occurs 2 times per day when water rises up the beach the farthest. Label the high tides on your notes.

Low Tides Occurs 2 times per day when water falls to its lowest level farthest down the beach. Label the low tides on your notes.

Spring Tides Occurs 2 times per month when high Tides reach their highest level. Occur when the Sun, Moon and Earth are in a line (new/full moon). Label the picture of the spring tide on your notes.

Neap Tides Occurs 2 times per month when high tides reach their lowest level. Occur when the Sun, Moon and Earth form a right angle. Label the neap tides on your notes.

Currents

Ocean currents 2 types of currents: Surface current Thermohaline (Deep water) current

What are Surface Currents? Mass of horizontally flowing (warmer) ocean water moving from one place to another towards the surface. http://www.classzone.com/books/earth_science/terc/content/visualizations/es2401/es2401page01.cfm?chapter_no=visualization

What causes Surface Currents? Surface currents are caused by global and seasonal winds Direction of currents is caused by Coriolis Effect http://www.classzone.com/books/earth_science/terc/content/visualizations/es2401/es2401page01.cfm?chapter_no=visualization

Coriolis Effect Coriolis Effect: Earth’s rotation causes objects in the N. hemisphere move counterclockwise, objects in S. hemisphere to move clockwise

Ocean currents 2 types of currents: Surface current Thermohaline (Deep water) current

What are deep ocean currents? Temperature = least dense = floating water Temperature = more dense = water sinks Thermo = heat, haline = salt Deep ocean currents are vertical movements of water deep under the ocean water.

What causes deep ocean currents? Temperature = least dense = floating water Temperature = more dense = water sinks Thermo = heat, haline = salt Deep ocean currents are caused by differences in density (temperature & salinity)

This diagram is a view of the deep ocean currents of the world.

“Global Conveyor Belt” When combined with surface currents it results in a conveyor-belt movement of water around the globe!