Beaches are a type of landform found next to a stretch of water, such as a lake or sea. They usually contain sand, gravel or shingle and are formed by waves or currents. The sea will completely cover beaches during high tide, but at low tide, the water retreats, leaving a strip of beach exposed.
Sandbars are a popular beach feature that can be found on many beaches worldwide. They are bars of sand that run along the shore, sometimes stretching quite far out into the sea or even in a lagoon.
They are very often visible only during low tide and disappear during high tide, although they may still be accessible for walking on. The shape of a sandbar depends on how the waves move it, which means that they can vary from flat and gently sloped to very steep.
There are many different types of beach breaks and they are constantly changing due to ocean processes such as longshore drift, tropical storms, and hurricanes. Human activities such as dredging can also affect surf breaks and can build or destroy them over time.
The shape of a wave depends on the wind speed, the direction it is blowing, the swell intensity and intervals, and bathymetry (what is beneath the surface of the water). These factors all have an effect on the size and shapes of waves.
Waves form when wind pushes up surface water into a wave that then travels across the ocean surface until it encounters a shallow bottom. When it does, it slows down and topples over to create a breaking wave.
Breaking waves can be very powerful and are often considered the most exciting part of surfing. They are also one of the most dangerous, as they can be very hard to avoid.
Beaches are also home to various marine creatures and algae that live in the water. These animals and plants can make their homes in the sand, as well as in other marine habitats like coral reefs.
They can help to form some very interesting patterns on the beach. These patterns are called beach cusps.
Besides being an extremely cool thing to look at, these relief features are also important for detecting and measuring the swell and wave conditions.
It’s important to understand how waves work so you can enjoy your time at the beach more.
The basic principle behind breaking waves is that the bottom of a wave is made up of a series of gradually sloping surfaces, which are then topped over to create a powerful breaking wave. The abruptness of these changes in the contours of the bottom causes the power of the breaking wave to vary.
A sandbar, for example, can cause the bottom of a wave to slope a lot and can easily double over as the wave hits it. This can be seen on Carolina Beach after Hurricane Bonnie in 1998 and is a common feature found at most beach breaks around the world.