The waves
that occur in the ocean can be classified into several types depending on the
style of the generator. Ocean wave generator can be caused by: wind (wind
waves), the gravitational pull of the earth-moon-sun (tidal waves), earthquakes
(volcanic or tectonic) at seabed (tsunami), or wave caused by the motion of the
boat.
Waves that
occur daily and taken into account in the field of coastal engineering is the
wave of wind and tidal (tidal). The waves can form and damage the coast and
affect coastal buildings. Would generate wave energy flow and affect the
movement of sediment in the direction perpendicular to the coast (cross-shore)
and parallel to the beach (longshore). In the field of engineering technical
planning beach, the waves are the main factors taken into account because it
will cause the forces acting on coastal structures.
The height
and wave period depends on the length of the fetch rise up. Fetch is the
distance traveled from the beginning rises up wave propagation. Fetch is
limited by the shape of the land surrounding the sea. The longer the distance
fetch, wave heights will be even greater. Wind also has an important influence
on wave height. Stronger winds will produce larger waves.
Wave that
propagates from the deep ocean (deep water) to the coast will change shape due
to changes in the ocean depths. If the wave moves closer to shore, the movement
of the waves at the bottom of the seabed adjacent to slow. This is a result of
the friction / friction between the water and the shore base. Meanwhile, the
top of the waves on the surface of the water will keep going. More and headed to
the beach, the waves will be more sharply peaks and valleys will be more flat.
This phenomenon is causing the waves break.
Ocean waves
move towards the shore, one wave after another in succession throughout day and
night. Why do the coastal regions not get flooded? As you know, the matter in
the medium does not propagate along with the waves. This is why ocean waves in
reality do not carry seawater (as the medium) during their propagation while
the waves are propagating towards the shore, the seawater only moves up and
down and does not move forward. Therefore, although it seems as if the sea
water itself moves forward, in reality it does not. The sea water only moves up
and down, hence it does not cause the coastal regions to get flooded. Why do we
sometimes observe that a piece of paper or plastic is carried away by the ocean
waves to the shore? The horizontal motion of the paper or plastic is not due to
the ocean waves, but the breeze that exerts a resultant force on the paper
towards the shoreline.