Baymouth bar facts for kids

A baymouth bar is a cool natural landform that forms along coastlines. Imagine a long ridge of sand or gravel that stretches across the entrance of a bay. It can either partially block the bay or completely close it off, turning the bay into a lagoon or a calm body of water. These bars are usually made up of gravel and sand that the ocean currents have moved around.

What is a Baymouth Bar?

A baymouth bar is like a natural wall built by the ocean. It's a type of sandbank or spit that grows across the opening of a bay. This happens when a spit, which is a long, narrow ridge of sand extending from the land into the water, grows so long that it connects to the other side of the bay or to another piece of land. When it fully closes the bay, the water inside becomes much calmer and can even turn into a freshwater lake over time if rivers flow into it.

How Do Baymouth Bars Form?

Baymouth bars are created by a process called longshore drift. This is how it works:

• Waves usually hit the shore at a slight angle, not straight on.
• When a wave breaks, it pushes sand and pebbles up the beach.
• As the water flows back down the beach, it pulls the sand and pebbles straight back into the sea.
• Because the waves keep coming in at an angle, the sand and pebbles get moved along the coastline in a zigzag pattern. This constant movement of sediment along the shore is called longshore drift.

The Role of Longshore Drift

Over a long time, longshore drift carries a lot of sand and gravel. If there's a bay, this material can start to build up across its entrance. The sediment is deposited in the calmer waters of the bay's mouth. Eventually, enough material builds up to form a bar that stretches from one side of the bay to the other, creating a baymouth bar.

What Are Baymouth Bars Made Of?

Baymouth bars are mostly made of loose materials like sand, gravel, and sometimes even small pebbles. The exact mix depends on what kind of rocks and sediments are found along the nearby coastline. Stronger waves and currents can carry larger pieces of material, while gentler conditions lead to finer sand deposits.

Where Can You Find Baymouth Bars?

You can find baymouth bars in many places around the world where coastlines have bays and strong longshore drift. They are common features on coasts with a good supply of sediment. For example, some famous ones exist along the coasts of the United States, like parts of the Outer Banks in North Carolina, or in places like the UK. They show us how powerful and creative natural forces like waves and currents can be in shaping our planet's surface.