Cliffed coast

Ocean waves hit the land with force.

This makes steep walls of rock. These walls are called cliffs.

The waves eat the bottom of the cliff. This makes a hole under the rock. Soon, the top part falls down.

The sea carries the broken rocks away. This makes the land move back. Some cliffs move fast. Some move very slow.

Hard rocks stay strong for a long time. Soft rocks break more easily.

You might see plants growing on old cliffs. This means the sea does not hit them much anymore.

A cliffed coast is a land where waves make steep walls.

These walls are called cliffs. Waves hit the bottom of the cliff over and over. This is called abrasion, which means the waves wear the rock away.

This action makes a hole at the base. We call this a wave-cut notch. The rock above the hole starts to hang over the sea. Soon, the heavy top falls down. The sea then carries the broken rocks away. This causes the shoreline to move back inland.

Some cliffs move fast and some move slow. The chalk cliffs in England move only half a centimetre each year. The Mecklenburg coast in Germany moves about 25 centimetres every year.

Hard rocks like granite stay strong. Soft rocks break more easily. If the rock is very hard, a flat platform forms under the water. This is called an abrasion platform. If the waves carve a hole through a narrow point, they make a natural arch. When the arch falls, a tall pillar of rock called a stack is left behind.

A cliffed coast is a place where the land meets the sea with steep walls.

These walls are often called cliffs. Sometimes people call this an abrasion coast. This happens when ocean waves wear the land away. The shape of the coast depends on many things. It depends on how hard the rock is. It also depends on how the rock is layered.

Waves work in a very specific way to change the coast. The waves hit the bottom of the cliff constantly. This process is called abrasion. The waves carve out a hole at the foot of the cliff. This hole is called a wave-cut notch. As the notch grows, the rock above it hangs over the sea. Eventually, the heavy top part collapses. The sea then carries the broken pieces away.

Scientists have studied how these cliffs change over time. They look at how fast the shoreline moves inland. This movement is called retreat. Some coasts move very quickly. The Mecklenburg coast in Germany moves about 25 centimetres every year. Other places move much slower. The white chalk cliffs in southern England move only half a centimetre each year.

Different types of rock create different shapes on the coast. Hard rocks like granite or limestone create flat platforms. These are called abrasion platforms. They sit at the foot of the cliff under the water. If waves carve a hole through a narrow point, they make a natural arch. When that arch falls, a tall pillar called a stack remains.

A famous stack in Germany is named Lange Anna. In England, you can find the Old Harry Rocks in Dorset.

Cliffs can be living or dead. A living cliff is still being changed by the waves. The Red Cliff on the island of Sylt is a living cliff. A dead cliff is not changing much anymore. These cliffs are often covered in plants and green life. The Königsstuhl on the island of Rügen is a dead cliff. Some cliffs even form from huge debris avalanches. This happens on ocean island volcanoes like those in Hawaii.

A cliffed coast, often called an abrasion coast, is a coastal landscape defined by steep walls.

These cliffs may be very steep or slightly less precipitous. They form in areas where the land surface dips at a steep angle below the water table. The shape of the coast depends on many factors. These include the hardness of the material and how the rock is layered. The specific processes of erosion also change the final appearance of the coastline.

The formation of these cliffs involves a specific sequence of events driven by marine waves. This process is known as abrasion, which is the continuous action of waves on the coastline. The waves attack the foot of the cliff constantly. This constant energy carves out a feature called a wave-cut notch. As the notch grows deeper, it creates an overhang of rock above the water. Eventually, this overhang becomes too heavy and collapses under its own weight. The sea then carries the loose debris away from the cliff face.

As these collapses happen, the shoreline undergoes a process called retreat. This means the coastline moves further inland over time. The speed of this retreat varies greatly depending on the environment. Factors like the height of the cliff and the frequency of storm surges matter. The strength of the surf and the hardness of the bedrock are also key. For example, the Mecklenburg coast in Germany recedes by about 25 centimetres per year. In contrast, the chalk cliffs of southern England retreat by only half a centimetre each year.

The type of rock present determines the specific features found at the coast. On rocky coasts made of resistant materials like granite, limestone, or sandstone, an abrasion platform forms. This is a flat, rocky wave-cut platform located at the foot of the cliff. It stays at or below the water table level. If the coast experiences tectonic uplift, these platforms can be raised into coastal terraces. On coasts made of less resistant material, a beach forms instead of a platform.

Wave action can also create dramatic shapes like arches and stacks. If waves carve notches into both sides of a narrow promontory, a natural arch is formed. When that arch eventually collapses, a tall pillar called a stack is left behind on the platform. Notable examples of stacks include the Lange Anna on Heligoland in Germany. In England, the Old Harry Rocks in Dorset are prominent examples. These features show how the coastline changes as it recedes.

Geologists also categorize cliffs as either "living" or "dead." A living cliff is an active coast that is still being eroded and receding. The Red Cliff on the German island of Sylt is a living cliff. A dead cliff is one that is only reached by very high waves. Because they are not constantly hit, they undergo very little change. A sign of a dead cliff is the presence of vegetation growing on it. The Königsstuhl on the island of Rügen is a well-known dead cliff.

While waves are a primary force, other processes can create steep sea cliffs. General weathering of the bedrock is almost as important as wave action. Some cliffs are even formed by catastrophic debris avalanches. These massive landslides are common on the submerged flanks of ocean island volcanoes. Examples of such volcanic islands include the Hawaiian Islands and the Cape Verde Islands. These events show that cliffs can form through sudden, large-scale movements as well as slow erosion.