Erosion is the natural process by which soil, rocks, or dissolved materials wear away over time, transporting them over large distances. It differs from weathering in that no physical movement occurs during weathering processes.
River erosion occurs when water transports sediment along the bottom of a river or coastline, while ocean waves also contribute to this erosion process as they break up shorelines by carrying pebbles and sand away from them.
Water
Erosion is typically caused by liquid water, which washes away weathered soil and rocks from their original locations on the landscape, altering its form. Wind and glaciers may also contribute to water erosion.
Permeability and composition of soil greatly determine how much rainfall leads to erosion. Soils with higher clay content bind soil particles more closely, protecting against erosion. Sandy or silty soils tend to be more erosive. Compacted soils lose the ability to absorb rainfall efficiently, creating greater volumes of runoff during each rainstorm.
Erosion of water bodies is extremely destructive. Eroded soil clogs stream beds, disrupting their flow and filling them with sediment accumulation that reduces fish habitat quality while also inhibiting plant growth and leading to flooding on roads and bridges. Agriculture, deforestation and the use of chemicals on land all play a part in soil erosion but trees and other plants can provide some protection by binding together particles of soil while slowing raindrops and winds from moving too fast across it.
Wind
Wind erosion can carry dirt and particles away from surfaces by carrying fine sand- and silt-size particles over great distances by wind currents, while larger particles tend to roll or crash against each other on soil surfaces, particularly those located in arid regions. Erosion due to wind is particularly prevalent.
The constant pounding of ocean waves also results in erosion. Over time, waves erode beaches of pebbles and sand as well as rock formations such as sea arches. This constant wave action accounts for seven remaining sea stacks in Victoria Australia’s Twelve Apostles Marine National Park.
Soil erosion caused by agriculture, specifically intensive practices such as tilling and stripping, reduces crop productivity while simultaneously polluting rivers and streams, polluting reservoirs with sediment and depositing sediment into them. While dramatic images used to illustrate intensive agriculture’s effects can mislead people about what’s really going on, long-term monitoring studies provide more accurate scientific context regarding erosion rates and events.
Glaciers
Glaciers contain vast volumes of ice that scrape across rock surfaces and sediment layers like sandpaper, creating grooves known as striations patterns which demonstrate their impact. This exposes their impactful presence within nature’s ecosystem.
Glaciers can cause erosion on a massive scale, producing landforms such as rock basins, cirques, and fjords. Furthermore, glaciers may create smaller landforms like aretes (spiky mountain peaks). When combined with corries on either side of an arete peak it forms an pyramidal peak known as nunatuk.
Smaller glacial features include faceted clasts, striations and grooves in rocks, rock flour (ground up bits of eroded rock), as well as other signs that a glacier once existed here. Rainwater seeping through to its base can lubricate it more readily so it slides over rocks more quickly resulting in increased erosion rates. Rainfall and snowfall both have an influence on glacial erosion – rainwater percolating through to its base can allow more of it to percolate up through, thus increasing erosion rates significantly. Rainwater can percolate through to its base where it can help speed things up considerably by percolating through percolating through, increasing erosion rates dramatically! Rainwater can seep through to its base where it will allow more easily sliding over rocks faster thus increasing erosion rates exponentially! Rainwater percolates through to its base more quickly thereby increasing erosion.
Soil
Erosion is a natural process, yet human activities can accelerate it significantly. For example, when people cut down trees to plant agriculture fields or remove trees altogether to expose more ground vulnerable to erosion, more nutrients become lost through this process and harm both plant life and animals’ wellbeing.
Weather plays an essential role in erosion. Rain that falls on dry, loose soil causes more erosion than rainfall that falls onto moist, dense soil; intensity and duration of rainstorms also have a profound impact on erosion rates.
Wind erosion is another significant contributor to desertification. Wind can dislodge soil particles and transport them over great distances, often to rivers that carry their sediment downstream; one such river being Yellow River in central China which gained its name for carrying fertile yellow loess downstream and degrading the soil as it did so, stripping plants of their food source and contributing to desertification.