Down by the Seashore

Discover amazing shoreline landforms: sea stacks, beaches, estuaries, and barrier islands! Learn how waves shape the coast.

Down by the SeashoreBy Patti HutchisonThe shoreline is the place where the land meets the sea. Shorelines are shaped by waves and tides. Some are rocky; some have smooth sandy beaches.A wave breaking on a rocky shoreline is an awesome sight. A rocky headland is a point of land sticking out into the water. It receives most of the force of the eroding waves. These headlands have very interesting landforms.The water may cut steep cliffs into the shore. Below these cliffs, a wave-cut platform is created. This is a flat area of rock, which has been eroded over time. Along these platforms, weaker rocks are removed by the waves. Stronger rocks are left behind, often in fascinating formations.Sea stacks look like tall rounded chimneys sticking up out of the rock. Waves can form sea arches in the rock. They look like carved-out bridges.The sea waters can also cut caves into the rock at the surface of the water. Other shorelines are covered with beaches. A beach is a band of mostly level land. They are covered with sand, mud, or pebbles. They gently slope toward the edge of the water.The type of material that covers the beach depends on the wave action in the area. The waves deposit loose sediments on the shoreline. Large waves carry coarse materials such as pebbles and small stones. Gentler waves bring in smaller particles such as soft sand.Sandy beaches come in different colors. The color depends on the source of the material that is deposited. Hawaii has some black beaches. The sand is small grains of volcanic rock. The white and pink sand along the east coast is made from small pieces of coral and seashells. 1. The place where the land meets the sea is called the _. jetty barrier island shoreline 2. A flat area of rock that has eroded over time is called a _. wave-cut platform sea stack sea arch 3. What is a beach? An estuary is another land form along the shoreline. This is an area where a river or stream enters the ocean. Estuaries have brackish water. This is a mixture of freshwater and saltwater.Estuaries provide many natural benefits to an area. An estuary is like a nursery for young marine life. They provide food and shelter for many young fish. The sea grass that grows there helps filter out pollution.Have you ever walked out in the ocean? The water gets deeper as you go. After a short distance, it might get shallow again. You are on a land form called a sandbar. A sandbar forms in front of the beach. It is the result of wave action in the area.Erosion by wave action causes shorelines to be in a constant state of change. Sediments are continually moved and deposited. Over many years, barrier islands can form. These are long ridges of sand and other sediments. They are separated from the mainland. They can be large or small. The eastern coast of the U. S. is lined with a chain of barrier islands.The body of water that separates the mainland from a barrier island is called a lagoon. They are like lakes formed from salt water. They are connected to the open ocean by narrow, shallow inlets.Barrier islands are very unstable. Hurricanes and other large storms can wipe out large parts of these islands. Wave action constantly changes the shorelines of these islands.Many people have built homes and other buildings close to the shoreline. These structures are in danger of being damaged by wave action, especially during storms. To protect seashore properties, people sometimes build seawalls or jetties. These man-made structures might protect properties close by, but can actually harm shorelines nearby. Also, wave action can erode these structures over time. They have to be rebuilt.The ocean is always moving. Moving water causes erosion and deposition. This action changes the shoreline in dramatic ways. 4. An area where a river or stream joins the ocean is called _. an estuary a barrier island a reef 5. A mixture of salt water and freshwater is said to be _. contaminated distilled brackish 6. What is a lagoon?