Waves and Surf

Water MovementOcean waters move in patterns like the windThese patterns exist because of where our continents layThese patterns are called OCEAN CURRENTS

Message In A Bottle

Making WavesWaves are made of energy coming from winds blowing on the ocean surface

3 things tell us how big waves will be:How long the wind blowsHow hard the wind blowsHow big the area is

Waves Moving to ShoreThe energy moves to shore along currents

As it reaches shore, it forms a wave along the shallow waters

As the water gets more shallow, the wave grows bigger

Anatomy of a wave

Wave ShapeWaves break on shore in different ways

The bottom conditions determine what kind of waves we will have

A gradual sloping bottom will make different waves than a steep bottom

Spilling Waves happen when the bottom gradually gets more shallowThese waves can be powerful but generally are not steep and good learning wavesExample: HB, Doheny, and San Onofre,

Plunging Waves (Barrels) occur when the bottom goes from deep to shallow very quickly

Example: The Wedge

Surfs up in HBDuring the summer, our waves generally come from the Southwest (New Zealand, Fiji, and Indonesia)

During the winter, our waves come from the Northwest (Alaska and Japan)

Hurricanes in Mexico also send us large surf

Ocean Bottoms Around the WorldAlong our continents, there is shallow water that extends for miles out to sea

This is called the Continental Shelf

Most shelves slope gradually

Have an average depth of 200 feet

shelf

shelf

New Sea FloorOur continents drift on enormous plates (tectonic plates)The plates crash into one another and others move away from one anotherIn some places, new sea floor is being createdIn other places, old sea floor is being pushed back under the earth

Mid Atlantic TrenchAs lava creeps up from deep in the Earth, new sea floor is being madeOver time, the sea floor moves outward towards the continents

Old Sea FloorIn other parts of the world, tectonic plates crash into one anotherThis is where old sea floor is being forced back into the EarthThis is how many mountains are formed (Himalayan Mountains)Example: Japan, Oregon, South America