Learning Statement- Weathering and Erosion

Ever wonder how the Painted Cliffs in Tasmania or the Kannesteinen Vagstoy in Norway became some of the most famous and breathtaking rocks in the world? It has to do with weathering and erosion. These two processes help shape the Earth’s surface. They both belong to a process called the rock cycle. The rock cycle is when rocks break down and form new ones, shaping and re shaping the earth. When magma rises to the surface, it cools and forms igneous rock. This igneous rock eventually erodes, turns into sediment, and moves to the water. This compaction forms layers and now this igneous rock is sedimentary, and then metamorphic. Weathering and erosion play a big part in this as they break down rocks and form new ones. Weathering is the breaking down or dissolving of rocks or minerals into smaller particles on Earth’s surface. Water, ice, acids, heat, cold, wind, salts, plants and animals are all agents of weathering. Erosion is the process of weathering but also transporting these broken down rock particles.

There are two kinds of weathering-physical and chemical. Forces like wind, water and ice break down the surface of a rock by weakening it first. When wind moves over a rock for a long amount of time, physical weathering occurs. Water also weathers rock in many ways. It can flow over a rock and take bits off, waves crashing breaks rock, or even when water enters cracks in rock and freezes which is called frost shatter. On the other hand, chemical weathering is when a rock’s chemical properties have changed. This can be due to elements like oxygen going through rocks and causing a change and breaking it down. Types of chemical weathering are solution, hydrolysis and oxidation.

There are different kinds of erosion. There is erosion by water which is when weathered material mixes with mud and other matter by erosion. Water is what transports this sediment to the ocean. Rivers play a big part in water erosion. Rivers erosional action includes hydraulic action, abrasion, attrition, and corrosion. Rivers transport sediments by processes called solution, suspension, saltation and traction.

Wind erosion is also another powerful force in the process of erosion. It shapes and reshapes many of the Earth’s surfaces. There are two kinds of wind erosion called deflation and abrasion.

Ice is the last key component in erosion. Glaciers are the cause of this. Glacial ice forms when accumulation of snow is greater than ablation in the summer. As glacier’s move slowly over the earth, they scrape the surface, eroding it and carrying away rock and sediment. Plucking, abrasion, glacial deposition, till and outwash are the erosional actions of glaciers. Glaciers may only move a few inches or centimetres in a day, but they have the ability to shape anything in its way due to its weight and force and because of this, can create cirque’s, tarn’s, arete’s, col’s, horn’s, and striation’s.

Erosion, through the forces of water and wind, is constantly changing Earth’s surface by wearing down rocks and moving sediment around. These forces shape rocks and create new landforms. Fast moving water can erode and create canyons or valleys. Erosion can form deltas, and odd looking formations. Glaciers can form moraine’s.

Weathering and erosion have shaped Earth since the beginning, and without both of these important processes, rock would never break down and forms new ones. We would look at the same landscape for millennium as Earth’s surface would never change.      Weathering and erosion provide this Earth with magnificent landscapes where humans benefit greatly. They give us the chance to experience the world’s natural beauty, and leave people awestruck. People travel around the world in order to see magnificent landscapes. They also have the ability to be more than just geological features, but they can be homes, a trading route, or churches for people in the past. They connect us to history and give us great stories. They tie into culture and bringing people together. We can thank weathering and erosion for giving us these opportunities.