Weathering erosion deposition (WED) is the process by which rocks erode away while simultaneously building new locations with soil and rock deposits from erosion, such as waves transporting eroded material to beaches or gravel landing in riversbeds.
Plants help slow erosion by holding soil in place and slowing its movement away. Without plants, erosion would occur much more rapidly.
Rain, ice and river/stream/ocean waters can contribute to weathering and erosion processes. Water can erode rocks before transporting their debris elsewhere – known as deposition.
Erosion from water can create waterfalls, flood plains, meanders and oxbow lakes as well as cliffs and canyons. While some rock is so hard that its erosion occurs gradually over time, others such as sandstone can erode quickly; when this happens it creates mushroom-shaped rock formations.
Running water can carry loose materials downhill in what is known as runoff, such as soil and sand; sometimes dead plant matter also finds its way into this waste stream. When land remains barren for too long, soil erosion becomes greater than when plants cover an area.
Wind can blow small particles such as sand and dust away from their source, a process known as eolian erosion that is more likely to take place in arid regions where there is limited availability of water.
Particles like these can sandblast their way through rocks surfaces, creating smoothed or polished-looking rocks like those found at Arches National Park in Utah or creating high dunes like those seen at Badain Jaran section of Gobi Desert.
Weathering and erosion may be common phenomena, yet few truly understand their processes. Weathering is part of geology’s cycle that wears away rocks before building them back up again.
Force of nature (or geomorphic forces) are responsible for shaping Earth’s surface through processes like landslides and avalanches, as well as moving rock soil ice and other materials down slopes in what’s called mass movement.
Gravity can move materials using water currents, glaciers or even slowly over a prolonged period – for instance when ocean waves pound on rocks they wear away at their sides creating sand at beaches.
Physical erosion is the process by which rocks alter their physical characteristics without changing their chemical makeup, such as when rocks are pushed or pulled along the bottom of a glacier and ground up by mechanical means such as banging and grinding; or through chemical-mechanical weathering when plant roots penetrate cracks in rocks to form shattering and cracking, eventually leaving behind piles of boulders on landscapes or in talus slopes at the base of cliffs.
Changes in temperature can cause rocks to crack and crumble over time, with repeated freezing-thawing cycles often leading to slow expansion and cracking of rocks – known as physical weathering – while rainwater or waves striking a rock for extended periods also contribute.
Water can move rocks and soil from one location to the next through erosion, caused by gravity, running water, ice, plants and wind. Rivers erode land by carrying sediment downstream; creating waterfalls, flood plains and valleys along their paths. Waves also cause coastal erosion by transporting sand; creating beaches, sea stacks and cliffs along their coasts.
Certain kinds of rocks are more easily weathered than others. Some types can easily weather due to chemical compounds reacting with acidic raindrops and producing new soluble substances that can be easily washed away with acid rainwater; other kinds are harder to weather because they don’t contain these ingredients.