Erosion Forces WEATHERING How rocks are broken down

Erosion Forces

WEATHERING • How rocks are broken down. • Sediments and soil are made • Mechanical: physically broken down – Rivers, sandblasted, tree roots, freezing/thawing • Chemical: chemically broken down -Acid rain, rusting, dissolving

What is Erosion? • Erosion, is gradually wearing down the surface of the earth. • Erosion is the process by which weathered rock and soil (sediment) are moved from one place to another. • Erosion carves the Earth's surface creating canyons, gorges, and even beaches.

Erosion (transport) There are 5 main agents of erosion: 1. Gravity 2. Glaciers 3. Wind Weathering has to happen before erosion. The rocks 4. Water have to be broken into smaller sediments before they can 5. Man be eroded away. Wind Erosion Glacier

Gravity causes erosion Creep, Slump, Landslides, Mudslides, and Avalanches. Slower Faster These are examples of mass movement landslide clip. mpeg (or called mass wasting)

In this picture the land has slumped into the road below.

This is a diagram of creep. The hillside slowly slips over many years from temperature or water.

This is a picture of an avalanche. It is similar to a landslide with ice and snow instead of rock.

Glacier Erosion • Glaciers are ancient packs of ice and snow, they move by melting and refreezing. • Glaciers cause erosion. As glaciers pass over land, they erode it, changing the Earth’s feature. • Glaciers can move and redeposit material.

What are some features that glaciers have created?

Two types of glaciers • Valley Glaciers • Continental Glaciers

Wind Erosion

Water Causes Erosion • runoff, rivers and, streams

Water causes Erosion When rain falls to the Earth it can evaporate, sink into the ground, or flow over the land as Runoff. When it flows over land, erosion occurs. Runoff picks up pieces of rock and "runs" downhill cutting tiny grooves (called rills) into the land.

Consequences of Erosion • Buildings and other structures on slopes can be unsound due to the removal of vegetation and making a slope steeper. • Loss of important topsoil and filling up waterways • Steep slopes can be made safer with vegetation, drainage pipes, and concrete barriers.