Wind erosion can change the contours of Earth's meteor craters.
Like other bodies in the solar system, the Earth bears traces of numerous meteor impacts. Terrestrial meteor craters are mapped on land and under the ocean in areas around the globe. Active geological and meteorological processes, such as tectonic activity, rainfall and wind erosion change the contours of these craters over time or obscure them entirely.
Impact Craters in the Solar System
When a meteor strikes a planet or moon, it creates a crater -- a smooth bowl shape that may or may not contain fragments of the meteor. Impact craters retain their shape on bodies such as Mars, Venus and the Earth's Moon because these bodies lack major geologic or meteorologic processes which can deform their shapes. Craters which retain their smooth walls are called simple craters; if crater walls collapse inward, the crater is called complex.
Terrestrial Impact Craters
Over the course of its planetary life, the Earth has received more meteor impacts than its moon, yet its surface shows relatively few crater formations. This is due to Earth's powerful, active geological processes, which keep its surface and atmosphere in motion and conceals the traces of meteor strikes. Earthquakes, climate changes, and erosion by wind and rain can change the shape of craters or conceal them entirely under bodies of water or vegetation.
Wind Erosion on Craters
On Earth, wind is the major agent of erosion, particularly in desert areas with little surface water and vegetation to hold soil in place. Wind carries sand grains, which are heavy and abrasive enough to cut, polish and pit stone. In addition, strong winds shift sand and soil, resulting in constantly changing shapes, which obscure features on the earth underneath. In this way, crater shapes can be eroded, cut, or partially covered by the effects of wind.
Craters Affected by Wind Erosion
Although craters in wetter areas have been obscured by water or overgrown with vegetation, craters in dry areas such as the Wolfe Creek Crater in Australia and the ancient site at Aurounga in Chad, Africa, show clear effects of wind erosion. The Wolfe Creek Crater has been partially buried under repeated onslaughts of windblown sand and is only partially recognizable as an impact crater. The Aurounga Crater, primarily visible from the air, shows dark valleys across its center, cut by blowing sand for billions of years.
Tags: Wind Erosion, change contours, Creek Crater, erosion change, erosion change contours, Erosion Craters
