|MadSci Network: Earth Sciences|
The landforms we see on Earth have developed through interactions of agents such as water, wind, and ice with materials at the surface, as well as through geologic forces such as volcanic activity and earthquakes. The area of geology that is dedicated to studying landforms is call geomorphology.
The development of landforms is a very complex process. Volcanoes, such as those in the Cascade Range in your state, have developed through the build-up of volcanic material over time. At the same time these volcanoes are being eroded through the actions of water and ice.
Canyons, such as the Snake River Canyon, have been eroded into bedrock by the flowing water of the river, but geologic forces may also play a significant role in shaping the canyon.
Many mountain ranges in the Western U.S. have developed through a process of seismic activity (earthquakes) and erosion.
These are just a few examples of the many types of landforms to be found on Earth. It is important to note that some landforms take tens of thousands of years to develop, such as the Grand Canyon, and others can be drastically changed in a matter of minutes, such as what happened on Mount St. Helens.
Try the links in the MadSci Library for more information on Earth Sciences.