Geologic processes affect the landforms on our planet's surface.
Landforms are the natural, physical features of our planet's surface, or landscape. The shape and form (morphology) identifies the various landforms. Geologic processes are natural forces that change landforms, and other areas of the earth's surface. Changes caused by geologic processes constantly happen in both large and small ways. Changes are sometimes so gradual they are noticed only in retrospect
Glaciers
Glaciers are landforms that form when the winter snowfall exceeds the amount that can melt during the summer. The layers of snow turn into ice crystals, and compact into a huge mass of ice. The pressure caused by its enormous weight slowly makes the glacier move over the surface of the land.
Hills
Hills are landforms that rise higher than the land surrounding them, but are not as high as a mountain. Hills form in several ways. One way is when glaciers pushed rock and sand debris as they slowly crept over the land, forming the hills. Volcanoes, faults, disturbances in the earth's crust and erosion are other ways natural hills form.
Mountains
Mountains are landforms of steep land elevations that are higher than hills. Volcanoes, erosion and disturbances of the earth's crust cause mountain formation. Geologists believe most mountains form from plate tectonics, the movement of the earth's crust and changes under the crust caused by heat and pressure.
Plains
Plains are landforms with large areas of mostly flat land. They are typically at a lower elevation than the land surrounding them, but may occur at high elevations.
Plateaus
Plateaus are landforms with large areas of primarily flat land that rise steeply above the surrounding land. They form from lava flow, erosion of nearby areas or an upward lift in the earth's crust.
Valleys
Valleys are elongated, trough-like areas of land. Valleys form because of the geologic process of erosion by rivers or glaciers as they move between higher landforms, such as hills or mountains.
Erosion and Weathering
The geologic process of weathering causes small bits of rock in the surface layer of the earth to break apart. Several natural factors cause weathering, such as plant roots, expansion caused by freezing water, running water, animals that burrow into the ground, extreme temperature variations, wind, salt and natural chemical processes. Erosion carries the small particles and soil away from the area, resulting in a wearing away of the earth's surface. Water causes a powerful erosion process.
Impact Cratering
Impact cratering is a geologic process caused when objects from outside the earth's atmosphere hit our planet's surface and leave a depression.
Plate Tectonics
Plate tectonics is a geologic process theory that the earth's surface is broken down into 12 plates. The plates move around on the mantle, sometimes pushing against each other, or sliding on top of each other. When this happens, faults appear that cause volcano, earthquake and mountain formations.
Tags: earth crust, geologic process, earth surface, planet surface, with large areas
