why do waves always blow into shore regardless of wind direction? eg on every shore of a loch at same time!?

Question

If you walk round a loch(lake) the waves all come into shore even in a strong wind....why?

Answer 1

Well that is true, but you will generally find that the waves are much stronger on one side of the loch (the side downwind of the wind) than the other side.
So why are there any waves on the other side? because of refraction of the main waves - waves can change direction if they encounter variation of depths side to side
Also a small part of the power of the main waves will reflect off the shore and head off in the opposite direction so creating the smaller waves on the opposite shore.

But if it's loch ness, then all waves are caused by nessie swishing its tail...

Answer 2

The optical analogy to this is light refraction. For optical materials of high index of refraction, even for light striking it at low angles continue inside the material at steeper angles. The typical beach, because of a typically occuring slope under the water, is better approximated by a non-linear optical material with an increasing index of refraction. The result is that all the waves finally breaking near the shore appear to be parallel to the beach, regardless of the direction of the original waves out at sea. In fact, the wave aren't always exactly parallel to the shore, but often come in at slight variations. Seasoned surfers recognize this by observing that some sets of waves break from left to right, and others vice versa.

Answer 3

That's not always true (sometimes they all blow in). The direction of the convection current depends on the temperature of the land compared to the lake. If the lake is cold and the land is hot, then the air over the land rises and the over the lake sinks. So at low altitudes, air blows from the lake onshore. Up high, air is blowing from the land offshore. If you reverse the temperatures, the convection pattern reverses.

Oops--I misread the question, though you said wind (waves don't blow!). Someone below got it right--waves propagate out from disturbances on the lake (from wind or tides or whatever), so at the shore, they are always going onto shore.

Answer 4

Waves aren't created by wind, they are created by disturbances in the water. Just as ripples expand outward when you drop a stone into the water, so do waves always propagate outwards from the source of the disturbance.

In a lake or an ocean, the disturbance can be changes in temperature, minor earthquakes, or changes in air pressure, or an effect of tides. The effects can be tiny, but over long distances, they reinforce each other to form ocillations which become waves when they reach shore.

HBJ

Answer 5

They don't always come in parallel to shore, but that's a strong tendency. The cause is refraction; the speed of the wave is greater in deep water than in shallow, so as a wave approaches shore, it tends to turn toward the shoreline.

Answer 6

I questioned the validity of the waves all coming onto an atoll (in 'Castaway' with Tom Hanks), but I suppose this could happen. I think it has to do with the pull of the Moon which is very strong.

It also changes the moods of humans too (since we are made up of such a large percentage of water).

Answer 7

Waves are affected by diffraction and bending. Therefore, they will spread out after going through a small opening, and spread around the sides of the lake.

Answer 8

seems like wind does play a big part in creating waves. check this site out.

Answer 9

Because wind is in the air.

Current is in the water.

"AIR" only touches the top centimeter of a wave, while water touches about the bottom 95%.

Its like your friend blowing the bottom and middle of a tennis ball towards you

and you only blow the top of the tennis ball back towards him.

As you will quickly learn, if you dont blow the middle of the tennis ball--it aint going anywhere.

Answer 10

Wind can increase the size of waves, but winds don't blow waves around. Water sloshes.