wind waves

shape of a wave

Water molecules in waves make circles or ellipses (Figure 1.1). Energy transfers between molecules, but the molecules themselves mostly bob up and down in place. The circles show the motion of a water molecule in a wind wave. Wave energy is greatest at the surface and decreases with depth. "A" shows that a water molecule travels in a circular motion in deep water. "B" shows that molecules in shallow water travel in an elliptical path because of the ocean bottom.

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building big waves

Ocean waves originate from wind blowing - steady winds or high storm winds - over the water. Sometimes these winds are far from where the ocean waves are seen. What factors create the largest ocean waves? The largest wind waves form when the wind is very strong blows steadily for a long time blows over a long distance The wind could be strong, but if it gusts for just a short time, large waves wont form. Wind blowing across the water transfers energy to that water. The energy first creates tiny ripples, which make an uneven surface for the wind to catch so that it may create larger waves. These waves travel across the ocean out of the area where the wind is blowing. Remember that a wave is a transfer of energy. Do you think the same molecules of water that start out in a wave in the middle of the ocean later arrive at the shore? The molecules are not the same, but the energy is transferred across the ocean.

storm surge

Some of the damage done by storms is from storm surge. Water piles up at a shoreline as storm winds push waves into the coast. Storm surge may raise sea level as much as 7.5 m (25 ft), which can be devastating in a shallow land area when winds, waves, and rain are intense. Maverick waves are massive. Learning how they are generated can tell scientists a great deal about how the ocean creates waves and especially large waves. Click image to the left or use the URL below. URL: Click image to the left or use the URL below. URL:

waves break

When does a wave break? Do waves only break when they reach shore? Waves break when they become too tall to be supported by their base. This can happen at sea but happens predictably as a wave moves up a shore. The energy at the bottom of the wave is lost by friction with the ground, so that the bottom of the wave slows down but the top of the wave continues at the same speed. The crest falls over and crashes down.

ocean waves

Waves have been discussed in previous concepts in several contexts: seismic waves traveling through the planet, sound waves traveling through seawater, and ocean waves eroding beaches. Waves transfer energy, and the size of a wave and the distance it travels depends on the amount of energy that it carries. This concept studies the most familiar waves, those on the oceans surface.

instructional diagrams

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questions

waves break when they become too tall to be supported by their base.

-->  a) true

b) false

water that is pushed in a pile near shore by storm winds causing sea levels to rise locally.

a) massive wave

b) flood

-->  c) storm surge

d) none of the above

waves get started when

-->  a) wind energy creates tiny ripples that are easier for later winds to catch onto.

b) wind gusts fast across a flat sea.

c) a high pressure cell pushes down on the sea surface so that when it bounces back it starts waves.

d) none of these.

in deep water, water molecules travel in a ____ motion.

a) back-and-forth

b) up and down

c) random

-->  d) circular

wave energy is lowest at the surface and increases with depth.

a) true

-->  b) false

the energy contained in bottom of the wave is reduced due to friction with the shore.

-->  a) true

b) false

the largest waves are built by

a) very strong winds.

b) winds that blow steadily for a long period of time.

c) winds that blow over a long distance.

-->  d) all of these.

the water in a wave travels across the ocean to end up on a shoreline.

a) true

-->  b) false

why does a bottle appear to bob in place when its in a lake with small waves?

a) the bottle experiences just up and down motion.

-->  b) the bottle is moving in a circle, but staying roughly in place.

c) the bottle appears to stay in place, but it is actually moving slowly forward.

d) none of these.

diagram questions

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