Wind degradation
Introduction
Wind erosion is the wearing away of rocks or the removal of soil due to the action of the wind. Wind is a landform-shaping agent that can carry large amounts of dust across the world, but grains of sand can only be transported relatively short distances. Quartz is the most abundant mineral in sand particles; It is normally resistant to chemical weathering, dissolution and abrasion.
Sand is distributed throughout the earth's surface, but particularly in deserts, coasts, river estuaries and spaces that have experienced glaciation. It seems that water may have been the original agent that caused the concentration of the powerful sand masses of the deserts. The wind would be the agent of redistribution and the genesis of a wide range of sedimentary forms. Many of the large deposits, especially the so-called sand seas or ergs, appear to be the result of important river activity during the Quaternary.
Definition and environment
Aeolian processes are those processes of erosion, transport and deposition "Deposition (geology)") of sediments that are caused by wind on or near the Earth's surface.[1] Sediment deposits produced by the action of wind and the characteristic sedimentary structures of these deposits are also described as aeolian.[2].
Aeolian processes are more important in areas where there is little or no vegetation.[1] However, aeolian deposits are not limited to arid climates. They are also observed along the coasts; along stream courses in semi-arid climates; in areas of extensive weathered sand from weakly cemented sandstone outcrops; and in areas of glacial outcrop.[3].
Loess, which is wind-deposited silt, is common in humid to subhumid climates. Much of North America and Europe are covered by Pleistocene sand and loess from glacial flows.[3].
River valleys in semi-arid regions are usually covered with sand and lee dunes. Some examples in North America are the Platte, Arkansas and Missouri rivers.[3].
Wind as an agent of erosion
Wind is an effective agent for the erosion of fine and loose materials, capable of uprooting, lifting and transporting particles, and its ability to erode harder compact rocks depends largely on the speed of the wind and the greater or lesser compaction of these rocks from the Earth's surface. Although the speed determines the wind's ability to erode and drag particles, the character of the materials, the topography of the terrain, the protective effectiveness of the vegetation, etc. also influence it. In the case of the Sahara, the wind can reach hurricane speeds, which can cause considerable erosive action, taking into account the characteristics of the Mohs scale: a mineral or rock with a hardness of 7 points (such as quartz) can scratch other minerals that have the same hardness or less. The sandblasting technique, essential in the oil industry, is based on this idea.