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Geomorphology explained

A bend, known as a

From mountain ranges to trickling streams, geomorphologists study why the Earth is shaped the way it is. Read on to find out more.

Most people learn in school about why rivers are bendy, or where mountain ranges come from. Geomorphology sorts these mechanisms into “processes”, so the effects of water are fluvial processes while the effects of moving tectonic plates are tectonic processes. Geomorphologists try to work out how these processes happen, and how they interact with each other. Other processes include:

Igneous processes: Volcanoes and the molten rock below the Earth’s surface help to form its shape. It’s fairly obvious how the molten rock produced by a volcanic eruption can change the shape of the Earth, but other features are formed by magma slowly coming out of cracks in the crust, and even magma moving under the surface can make land move up and down.

Hillslope processes: It might surprise you, but some people really do study how rocks roll down hills. The way earth and rock moves down slopes can make a big difference to the Earth’s shape: in particular, if a hill gets too steep a lot of material can come down very quickly, restricting how quickly it can grow.

Aeolian processes: Even the wind affects geomorphology. This can be seen easily in deserts or at some beaches, where sand dunes shift around in the wind, but it happens everywhere. For example, where there are large, soft sandstones, the wind can erode large depressions called alcoves.

Biological processes: Have you ever seen an old tree blown over in a storm? They can leave behind a huge hole where their roots have been ripped up. This is called “tree throw”, and it’s one example of a biological geomorphic process. Biological processes range from animal burrows to the way living thingsMount Rushmore, with the carved faces of US Presidents George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln. affect the climate which, in turn, affects the landscape.

Human processes: Whether it’s building canals, carving faces in Mount Rushmore or blowing holes in the ground with bombs, humans change the landscape in all sorts of ways which geomorphologists take into account.

Extraterrestrial processes: No, it’s not aliens writing interplanetary graffiti on the Earth – although that would be part of geomorphology too! If you’ve ever seen a picture of a meteorite impact crater, you’ll know that objects from outer space can make a big difference to the shape of the planet. One crater in South Africa is 300km across and 2020 million years old!

Meteor Crater, which is about 2.4 miles across.These are just some of the systems geomorphologists use to understand the Earth’s shape. Geomorphologists also have to divide their studies up into different scales – because studying continents is very different to studying ditches. But as well as being a fascinating subject in its own right, geomorphology helps to predict and protect against landslides, fight coastal erosion and maintain or alter the course of rivers.