PROPERTIES AND STRUCTURE OF EARTH
Weathering is the changing of rocks near the earth’s surface through the actions of natural elements such as wind, rain, heat, wave action, ice and snow. The Earth’s surface is constantly changing and breaking down due to the process of weathering and the effects of erosion.
Weathering breaks rocks into smaller pieces while erosion carries these weathered materials from one place to another. Weathering occurs because of the changes in temperature and exposure to water and air (water, wind, ice and gravity are agents of erosion).
Once rock is weathered and eroded, water, wind, ice and gravity deposit weathered material from the rocks to other places. This process is known as deposition.
Earthquakes cause rapid changes on earth. An earthquake is a vibration or shaking of Earth’s crust. Most earthquakes occur along faults. A fault is a break in the crust along which rock moves. Rock on either side of a fault can move up and down, side to side, or both. Earthquakes are measured on a Richter Scale which uses numbers from 1-9.
A volcano is a mountain that forms when red hot melted rock flows through a crack onto the earth’s surface.
Melted rock inside Earth is called magma.
Melted rock that reaches Earth’s surface is called lava.
The lava and gases that erupt from volcanoes are very hot and often destroy everything in their path. Volcanic eruptions also form new crust on continents.