Weathering erosion deposition (WED) is the process of wearing down and moving rocks and other materials over time, and we see its effects everywhere on Earth – roads and sidewalks cracked from ice damage are a prime example, while beaches often show evidence of this process as well as deposits of sand from weathered lava deposits.
Weathering can take place either physically, through heating and cooling or frost wedging, or chemically through acid rain that dissolves limestone and other rocks.
Rainwater can erode rocks and soil, breaking it apart into smaller particles. When this material gets carried away by runningoff or through streams and rivers it causes erosion; sometimes even lakes become affected.
Weathered rocks may be transported through gravity, ice, wind or other forces and become sediment like sand, silt or gravel which becomes known as “clastic debris.”
River erosion is another type of erosion which involves water. It often results in waterfalls, flood plains, meanders and oxbow lakes being formed as features emerge along riversides.
When streams flow over flat terrain they often slow down and begin dumping their load of material, creating alluvial fans and deltas. Landslides or mass wastings involve lots of water; they can move tons of earth and alter mountainous features while covering buildings and people.
Ice can erode Earth’s surface and form dramatic landforms. In frigid areas, glaciers move slowly downhill across the ground eroding rocks and soil they carry–from tiny grains of sand to massive boulders–leaving an impressive wake of debris known as glacial till.
Ice erosion leads to both physical and chemical weathering processes. Repeated heating and cooling cycles cause rocks to crack and disintegrate while its chemicals transform other rocks into new minerals.
As the ice melts and weathered rock particles are carried away by flowing water, gravity, and wind they are eventually deposited at new locations – an accumulation known as sediment. Rivers, streams, ocean waves and blowing sand transport this sediment, leading to its deposition as waterfalls, flood plains, valleys gorges sand beaches as well as caves sea stacks arches and wave-cut cliffs being formed as a result. This form of mechanical weathering also forms coastlines while creating waterfalls flood plains flood plains flood plains gorges as well as shaping coastlines as well as shaping coastlines by shaping coast lines while creating waterfalls flood plains flood plains as flood plains flood plains flood plains as flood plains as flood plains whilst shaping coastlines creating waterfalls; flood plains; valley gorges as well as creating caves sea stacks arches and wave cut cliffs all created due to wave action from ocean waves passing close enough.
Wind erosion can be an enormously powerful force, carrying away silt and clay-sized particles for great distances, even carving rocks into interesting forms. Wind erosion tends to be most noticeable in dry climates where soil moisture levels are minimal or nonexistent.
Chemical erosion is another widespread occurrence. Raindrops bring rainwater that dissolves limestone rock that forms caves and sinkholes to the surface, dissolving it in their droplets as raindrops fall onto it. This process creates chemical eroded surfaces.
Some types of rocks are more resistant to weathering and erosion than others, but no rock is immune. Over time, sunlight’s heating and cooling cycles, freeze thaw cycles, mechanical wear on rocks, chemical dissolution of an atom of rock at a time, gravity forces, tectonic forces will eventually wear down every rock; erosion is an unstoppable force which doesn’t rest!
Human activity can hasten the weathering erosion process, hastening its speed. Air pollution from burning fossil fuels such as coal, oil and natural gas produces sulfurous and nitrogenous emissions which, combined with rainwater runoff, create acidic waters which accelerate chemical weathering of rocks.
Deforestation and land clearing activities such as plowing fields or overgrazing livestock increase erosion rates 10-20 times more rapidly than natural geologic forces do, creating massive sediment accumulation in lakes and rivers and worsening their quality of water. Erosion causes increased sediment to enter bodies of water which degrades its quality over time.
Construction of roads, buildings and cities often leads to soil erosion in many regions, while coastal erosion by waves remains an ongoing issue. Human activity has moved more materials in just 100 years than natural erosion has moved over millions of years; as a result, some scientists suggest we now exist in an anthropocene geological period.