Weathering erosion and deposition continuously transform Earth’s rocky landscape, leaving behind landmarks like this huge canyon in Arizona in the U.S.
Wind, water, ice and gravity are natural forces which erode rocks by breaking them down and transporting them away from this region.
Weathering is the process of breaking down rocks and minerals through contact with weathering agents such as water, ice, acids, plants or animals; or temperature variations. This takes place at the surface of Earth without transport of materials being involved.
Most forms of weathering take thousands or millions of years to occur, though occasionally rapid mudslides form, hastening weathering process significantly.
Water is one of the primary agents of weathering and erosion. It can seep into cracks in rocks before freezing to form wedge-like crystals that will erode away rock layers like an ice pick chisel, splitting apart entire rocks. Ice wear also wears away at rocks making them soft enough for more fragile pieces to break off and fall away more readily than before. Wind can further cause weathering by carrying away bits of rock to new places where they become worn away by wear and tear – producing features like mushrooms or canyons like Grand Canyons as well as beaches with ocean waves depositing sand onto shorelines from ocean waves carrying it back from further uprivering places inland and depositing it on shoreline rock faces.
Erosion is the process by which natural forces use gravity, running water, glaciers, waves and wind to transport rock and soil material from one location to the next, loosening, transporting and depositing it as sediment (sand, silt and mud).
Erosion can wear away rocks and break them apart, while waterborne chemicals may change their shapes; limestone erosion creates caves and sinkholes while flowing rivers can carry away its contents.
Erosion rates depend on various factors, such as climate, topography, vegetation and tectonic activity. A floodplain may be more prone to erosion than steep slopes; while wind-driven aeolian erosion transports sand particles far and wide – giving some landscapes their distinctive look.
Subsurface weathering or erosion processes lead to tiny pieces of earth being worn away, worn down by ocean waves crashing against rocks, wind gusts or glaciers depositing them elsewhere. One such method that deposits this eroded material is through beach sand deposition by waves breaking on them – for instance sand can also be transported along other routes such as wind or glaciers.
Physical weathering occurs when rocks change their form without altering their chemical makeup, which may occur through heating and cooling cycles, water entering cracks in rocks that then freezes out, living organisms growing into them or animals traversing over it, among other causes.
Physical weathering leads to physical erosion, which is the force that moves dirt, rocks and other debris from one location to another through wind, ice or water (including river sediment) movements. Deposition is the geological process in which material is added onto landforms through deposition processes.
Landforms, which are formed through weathering and erosion processes, include mountains, valleys, plains and beaches.
Physical weathering breaks rocks into smaller pieces that are carried away by erosion and deposited elsewhere, called sediment. The pieces might range in size from boulders to microscopic clay particles and over time will mix with other materials to form soil; geologists refer to this material as regolith.
Chemical weathering requires water and oxygen in order to take place, producing reactions which make rocks softer and easier to break apart. Chemical weathering occurs more commonly in regions with heavy rain.
Forces acting to erode and wear down mountainous areas transform rough peaks into more gentle ones, and flat, featureless areas are created. These are known as peneplains. Glacier ice can also erode rocks to carve caves – these features are known as glacial features – or split rocks apart into multiple pieces like the famous Split Apple Rock of New Zealand.