January 25, 2010

Landforms and Changes in the Earth's Surface Vocabulary Guide

Weathering is the wearing away of earth materials. It is a constant process. Weathering is caused by many things including wind, ice, water and chemicals.

Erosion is when weathered earth materials move from one place to another.

Deposition is when eroded earth materials stop moving and settle in a new place. One way to remember this is to think DEPOSIT.

Key Point: often times "erosion" is used to describe all 3 process above. However on your assessment, you will need to be able to understand all 3 terms independently.

January 25, 2010

Weathering: the water has worn down the earth material forming the V-shaped canyon.

Erosion: The earth materials or sediments are moving down the channel.

Deposition: The sediments have settled to create a delta.

Hopefully this diagram will help you to remember how all 3 of these terms work together

January 25, 2010

Landforms: Plains

Plains are generally flat landforms. In some cases plains were formed by glaciers that pushed across the earth. Most of the western half of Ohio is considered a plain. Plains are also usually considered lowlands.

January 25, 2010

Landforms: PlateausPlateaus are like plains,but they are generally because they are flat surfaces. They are different because plateaus are higher than the surrounding areas. Plateaus can be formed in many ways, but the most common way is that over a long period of time, pressure from inside the earth pushed a large section of the earth upward.

Creating a plateau is a slow process.

January 25, 2010

Landforms: Valleys

Valleys are have more gently sloped wall and are more U-shaped than canyons. Valleys are often thought to be between mountains or mountain ranges. Some valleys are the result of a glacier moving through an area between mountains. The floor of a valley can be very large and often times, valleys have fertile soil in them.

January 25, 2010

Landforms: CanyonsCanyons are steep-walled, V-shaped landforms that are caused by a river weathering and eroding away materials from a plateau. The making of a canyon is a very slow process, sometimes taking millions of years.

Sometimes the rift between two mountain peaks is also called a canyon.

January 25, 2010

Landforms: Dunes

Dunes are landforms that are caused by wind eroding or moving large amounts of sand and depositing the sand in a new location. Dunes can be found in deserts and near oceans very easily.

Creating dunes is a slow process.

January 25, 2010

Landforms: DeltasDeltas are "fan-shaped" landforms that are caused by the erosion or movement of sand, rock and other earth materials by a river. When a river moves these material down river, the deposition of the materials into the ocean or sea is the delta.

Nile River Delta as seen from a satellite. Creating deltas is a slow process.

January 25, 2010

Landforms: HillHills are landforms that are generally smaller than 1,000 feet tall. Hills generally have rounded tops and smoothed sides. Hills can be formed in many ways, but one interesting way is that over a very long time a mountain can be weathered down into a hill.

January 25, 2010

Landforms: MountainsMountains are landforms that have been caused because pressure from inside the earth uplifts the earth's crust. Tectonic Plates that push together is another way mountains are formed. Mountains generally are taller than 1,500 ft and have pointed tops or peaks.

"Making" a mountain is a slow process.

January 25, 2010

Landforms: Volcanos Volcanos are landforms that are formed when magma inside the earth pushes through the earth's crust. Volcanos can be active or dormant. Many volcanoes start in the ocean and can eventually form islands after millions of years.

Even though it can take a very long time for a volcano to form an island, volcanic eruptions can change the surface of the earth very quickly so we call a volcano's effect on the earth a fast process.

January 25, 2010

Landforms: Glaciers Glaciers are massive sheets of ice that move very, very slowly over land (maybe a foot a year). Glaciers are formed by a process where lots and lots of snow accumulate over many years and the freezing/thawing cycle cause the formation of layers of ice and snow. When there is enough pressure because of the build up of ice and snow, glaciers will start to move.

January 25, 2010

Landforms: Glacial MorainesGlacial moraines are formed by the deposition of material from a glacier and glacial moraines are exposed after the glacier has retreated. Glacial moraines usually appear as linear mounds of a mixture of rock, gravel, boulders and a fine powdery material. Terminal or end moraines are formed at the foot or terminal end of a glacier.

The formation of a glacial moraine is a slow process.

January 25, 2010

EarthquakesEarthquakes are not landforms, but they do change the earth's surface a great deal. We would classify an earthquake as a fast process for changing the earth's surface. Earthquakes happen when there is a sudden release of energy in the earth's crust that creates waves of energy. These waves of energy cause the earth's crust to shake and crack.

Geologists observing theeffects of an earthquake inAlaska.