Erosion

Erosion is the way that rocks and soil are worn away by wind, water, ice and other methods. Our entire planet is carved and shaped by this process. Erosion carves gorges and valleys and leaves behind the landscapes that we recognize. Everything from the Lake District to the Somerset Levels, and the land that London is built on through to the Yorkshire Dales - all are shaped by the processes of erosion.

The movement of water is the major component of erosion. Rain will move soil and rocks that have been worn down by weathering, and carry them down the drainage basin into streams and eventually into the rivers. The rivers carry them even further before they are either deposited on flood plains or carried into the sea where they are moved again to form something else. Waves from the sea attack the cliffs that their erosion has formed, leaving coastal features such as stacks and caves.

It's not just liquid water that causes erosion though. Frozen water in the form of glaciers also changes the landscape. The movement of these glaciers plucks huge chunks out of rocks and scrapes soil ahead of them. These alien bits of geology are then dumped as the glaciers retreat. Wind also changes things. It scours landscapes, building up huge dunes on beaches and in deserts. Some dunes can reach heights of over 400m. The erosion can carve features like Uluru (Ayers Rock) in Australia. This is the remnants of a mountain range that has been almost completely erased.

Looking at how this material, worn down by weathering, is moved around by erosion is key to understanding so many processes, such as hydroelectric systems, how to protect buildings, how to protect beaches and so protect the settlements inland, and how to save people’s lives from flooding, landslides and sudden geological actions. In this quiz we will examine the action of rivers, coastal processes and ice on rocks and soils.