# data[].attributes.body
We identify rocks by looking at how they are form, texture, and their color.

# data[].attributes.body
Sediments sort themselves in a stream by   rolling along the river bottom.

# data[].attributes.body
One type of rock can become another by change within time

# data[].attributes.body
Igneous rocks are formed from melted rock deep inside the Earth. Sedimentary rocks are formed from layers of sand, silt, dead plants, and animal skeletons. Metamorphic rocks formed from other rocks that are changed by heat and pressure underground.

# data[].attributes.body
There are dead animals and insects in the soil, as well as minerals, insects, and water. Soil is beneficial because it aids in the growth of crops.

# data[].attributes.body
Landscapes are formed by tectonic plates by pushing into each other

# data[].attributes.body
We can identify rocks by looking at their form, texture, how they react to certain things and, their color.

# data[].attributes.body
It can change within pressure, weathering, and erosion. It can also change within time.

# data[].attributes.body
Overgrazing, deforestation, and Erosion are what change up the surface of the earth.

# data[].attributes.body
Most minerals can be characterized and classified by their unique physical properties: hardness, luster, color, streak, specific gravity, cleavage, fracture, and tenacity.

# data[].attributes.body
Erosion is a natural process, though it is often increased by humans' use of the land. Deforestation, overgrazing, construction, and road building often expose soil and sediments and lead to increased erosion. Excessive erosion leads to loss of soil, ecosystem damage, and a buildup of sediments in water sources.

# data[].attributes.body
Sedimentary rocks are formed from layers of sand, silt, dead plants, and animal skeletons. Metamorphic rocks formed from other rocks that are changed by heat and pressure underground.

# data[].attributes.body
Crystallization, erosion and sedimentation, and metamorphism transform one rock type into another or change sediments into rock.

# data[].attributes.body
Soil is composed of both biotic living and once-living things

# data[].attributes.body
weathering and erosion, shape the landscape

# data[].attributes.body
A topographic map is a map that illustrates the shape of an area.

# data[].attributes.body
Mechanical weathering- This is the breakdown of components in the crust of the earth by using physical forces.
Chemical weathering- The erosion of rocks caused by chemical reactions.

# data[].attributes.body
Sedimentary, Igneous, and Metamorphic rocks help shape our earth by changing the form and structures of places. It is what can determine where things such as sand could be.

# data[].attributes.body
The characteristics of the three types of rock are hardness, shape, texture, size.

# data[].attributes.body
"The action of erosion can create an array of coastal landscape features. For example, erosion can bore holes that form caves. When water breaks through the back of the cave, it can create an arch. The continual pounding of waves can cause the top of the arch to fall, leaving nothing but rock columns called sea stacks" source:

# data[].attributes.attachment_link.readable_text
Erosion is the opposite of deposition, the geological process in which earthen materials are deposited, or built up, on a landform.

Most erosion is performed by liquid water, wind, or ice (usually in the form of a glacier). If the wind is dusty, or water or glacial ice is muddy, erosion is taking place. The brown color indicates that bits of rock and soil are suspended in the fluid (air or water) and being transported from one place to another. This transported material is called sediment.

Physical erosion describes the process of rocks changing their physical properties without changing their basic chemical composition. Physical erosion often causes rocks to get smaller or smoother. Rocks eroded through physical erosion often form clastic sediments. Clastic sediment s are composed of fragments of older rocks that have been transported from their place of origin.

Landslides and other forms of mass wasting are associated with physical weathering. These processes cause rocks to dislodge from hillsides and crumble as they tumble down a slope.

Plant growth can also contribute to physical erosion in a process called bioerosion. Plants break up earthen materials as they take root, and can create cracks and crevice s in rocks they encounter.

Ice and liquid water can also contribute to physical erosion as their movement forces rocks to crash together or crack apart. Some rocks shatter and crumble, while others are worn away. River rocks are often much smoother than rocks found elsewhere, for instance, because they have been eroded by constant contact with other river rocks.

Liquid water is the major agent of erosion on Earth. Rain, rivers, floods, lakes, and the ocean carry away bits of soil and sand and slowly wash away the sediment.

Rainfall produces four types of soil erosion: splash erosion, sheet erosion, rill erosion, and gully erosion.

* Splash erosion describes the impact of a falling raindrop, which can scatter tiny soil particles as far as .6 meters (2 feet).

* Finally, gully erosion is the stage in which soil particles are transported through large channels. Gullies carry water for brief periods of time during rainfall or snowmelt but appear as small valleys or crevasses during dry season s.

Valley erosion is the process in which rushing streams and rivers wear away their banks, creating larger and larger valleys. The Fish River Canyon, in southern Namibia, is the largest canyon in Africa and a product of valley erosion. Over millions of years, the Fish River wore away at the hard gneiss bedrock, carving a canyon about 160 kilometers (99 miles) in length, 27 kilometers (17 miles) wide, and 550 meters (1,084 feet) deep.

The ocean is a huge force of erosion. Coastal erosion-the wearing away of rocks, earth, or sand on the beach-can change the shape of entire coastlines. During the process of coastal erosion, waves pound rocks into pebbles and pebbles into sand. Waves and currents sometimes transport sand away from beach es, moving the coastline farther inland.

Coastal erosion can have a huge impact on human settlement as well as coastal ecosystems. The Cape Hatteras Lighthouse, for example, was nearly destroyed by coastal erosion. The Cape Hatteras Lighthouse was built on the Outer Banks, a series of barrier islands off the coast of the U.S. state of North Carolina, in 1870. At the time, the lighthouse was nearly 457 meters (1,500 feet) from the ocean. Over time, the ocean eroded most of the beach near the lighthouse. By 1970, the pounding surf was just 37 meters (120 feet) away and endanger ed the structure. Many people thought the lighthouse would collapse during a strong storm. Instead, thanks to a significant engineering feat completed in 1999, it was moved 880 meters (2,900 feet) inland.

The battering force of ocean waves also erodes seaside cliffs. The action of erosion can create an array of coastal landscape features. For example, erosion can bore holes that form caves. When water breaks through the back of the cave, it can create an arch. The continual pounding of waves can cause the top of the arch to fall, leaving nothing but rock columns called sea stack s. The seven remaining sea stacks of Twelve Apostles Marine National Park, in Victoria, Australia, are among the most dramatic and well-known of these features of coastal erosion.

Wind is a powerful agent of erosion. Aeolian (wind-driven) processes constantly transport dust, sand, and ash from one place to another. Wind can sometimes blow sand into towering dunes. Some sand dune s in the Badain Jaran section of the Gobi Desert in China, for example, reach more than 400 meters (1,300 feet) high.

In dry areas, windblown sand can blast against a rock with tremendous force, slowly wearing away the soft rock. It polishes rocks and cliffs until they are smooth-giving the stone a so-called " desert varnish." Wind is responsible for the eroded features that give Arches National Park, in the U.S. state of Utah, its name.

Wind can also erode material until little remains at all. Ventifacts are rocks that have been sculpted by wind erosion. The enormous chalk formations in the White Desert of Egypt are ventifacts carved by thousands of years of wind roaring through the flat landscape.

Some of the most destructive examples of wind erosion are the dust storms that characterized the " Dust Bowl" of the 1930s in North America. Made brittle by years of drought and agricultural mismanagement, millions of tons of valuable topsoil were eroded away by strong winds in what came to be known as "black blizzards." These dust storms devastated local economies, forcing thousands of people who depended on agriculture for their livelihoods to migrate.

Ice, usually in the form of glaciers, can erode the earth and create dramatic landforms. In frigid areas and on some mountaintops, glaciers move slowly downhill and across the land. As they move, they transport everything in their path, from tiny grains of sand to huge boulders.

Rocks carried by glaciers scrape against the ground below, eroding both the ground and the rocks. In this way, glaciers grind up rocks and scrape away the soil. Moving glaciers gouge out basins and form steep-sided mountain valleys. Eroded sediment called moraine is often visible on and around glaciers.

Several times in Earth's history, vast glaciers covered parts of the Northern Hemisphere. These glacial periods are known as ice age s. Ice Age glaciers carved much of the modern northern North American and European landscape.

Ice Age glaciers scoured the ground to form what are now the Finger Lakes in the U.S. state of New York, for example. They carved fjords, deep inlets along the coast of Scandinavia. The snout of a glacier eroded Cape Cod Bay, Massachusetts, and formed the recognizable fishhook shape of Cape Cod itself.

Today, in places such as Greenland and Antarctica, glaciers continue to erode the earth. Ice sheets there can be more than a mile thick, making it difficult for scientists to measure the speed and patterns of erosion. However, ice sheets do erode remarkably quickly-as much as half a centimeter (.2 inch) every year.

Mass wasting describes the downward movement of rocks, soil, and vegetation. Mass wasting incidents include landslides, rockslides, and avalanches. Mass wasting can erode and transport millions of tons of earth, reshaping hills and mountains and, often, devastating communities in its path.

Factors Impacting Erosion

Some of the natural factors impacting erosion in a landscape include climate, topography, vegetation, and tectonic activity.

Climate is perhaps the most influential force impacting the effect of erosion on a landscape. Climate includes precipitation and wind. Climate also includes seasonal variability, which influences the likelihood of weathered sediments being transported during a weather event such as a snowmelt, breeze, or hurricane.

Topography, the shape of surface features of an area, can contribute to how erosion impacts that area. The earthen floodplains of river valleys are much more prone to erosion than rocky flood channels, which may take centuries to erode. Soft rock like chalk will erode more quickly than hard rocks like granite.

Vegetation can slow the impact of erosion. Plant roots adhere to soil and rock particles, preventing their transport during rainfall or wind events. Trees, shrub s, and other plants can even limit the impact of mass wasting events such as landslides and other natural hazards such as hurricanes. Deserts, which generally lack thick vegetation, are often the most eroded landscapes on the planet.

Finally, tectonic activity shapes the landscape itself, and thus influences the way erosion impacts an area. Tectonic uplift, for example, causes one part of the landscape to rise higher than others. In a span of about 5 million years, tectonic uplift caused the Colorado River to cut deeper and deeper into the Colorado Plateau, land in what is now the U.S. state of Arizona. It eventually formed the Grand Canyon, which is more than 1,600 meters (1 mile) deep and as much as 29 kilometers (18 miles) wide in some places.

Deposition, Soils, and Sediments

Eroded sediments have profoundly influenced the development of civilizations around the world.

River deltas are made almost entirely of sediment that has eroded from the banks and bed of a river. The rich delta soils of the San Joaquin and Sacramento rivers in northern California, for example, have created one of the most agriculturally productive areas in the world.

Loess is an agriculturally rich sediment made almost entirely of wind-blown, eroded sediment. The Yellow River in central China gets its name from the yellow loess blown into and suspended in its water. The fertile lands around the Yellow River have been among China's most productive for thousands of years.

Erosion is a natural process, but human activity can make it happen more quickly.

Human activity altering the vegetation of an area is perhaps the biggest human factor contributing to erosion. Trees and plants hold soil in place. When people cut down forests or plow up grasses for agriculture and development, the soil is more vulnerable to washing or blowing away. Landslides become more common. Water rushes over exposed soil rather than soaking into it, causing flooding.

The rise in temperature is also quickly melting glaciers. The slower, more massive form of glacial erosion is being supplanted by the cumulative impact of rill, gully, and valley erosion. In areas downstream from glacial snouts, rapidly melting glaciers are contributing to sea level rise. The rising sea erodes beaches more quickly.

Sometimes, engineers simply install structures to physically prevent soil from being transported. Gabions are huge wireframes that hold boulders in place, for instance. Gabions are often placed near cliffs. These cliffs, often near the coast, have homes, businesses, and highways near them. When erosion by water or wind threatens to tumble the boulders toward buildings and cars, gabions protect landowners and drivers by holding the rocks in place.

Erosion control also includes physically changing the landscape. Communities often invest in windbreaks and riparian buffers to protect valuable agricultural land. Windbreaks, also called hedgerows or shelterbelt s, are lines of trees and shrubs planted to protect cropland from wind erosion. Riparian buffers describe plants such as trees, shrubs, grasses, and sedges that line the banks of a river. Riparian buffers help contain the river in times of increased stream flow and flooding.

Living shorelines are another form of erosion control in wetland areas. Living shorelines are constructed by placing native plants, stone, sand, and even living organisms such as oysters along wetland coasts. These plants help anchor the soil to the area, preventing erosion. By securing the land, living shorelines establish a natural habitat. They protect coastlines from powerful storm surges as well as erosion.

Articles & Profiles

Websites

Credits

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Editor

Jeannie Evers, Emdash Editing

Producer

Caryl-Sue, National Geographic Society

Last Updated

March 20, 2018

User Permissions

For information on user permissions, please read our Terms of Service. If you have questions about licensing content on this page, please contact ngimagecollection@natgeo.com for more information and to obtain a license. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. She or he will best know the preferred format. When you reach out to him or her, you will need the page title, URL, and the date you accessed the resource.

Media

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text

Text on this page is printable and can be used according to our Terms of Service.

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Jeannie Evers, Emdash Editing

# data[].attributes.attachment_link.description
Erosion is the opposite of deposition, the geological process in which earthen materials are deposited, or built up, on a landform. Most erosion is performed by liquid water, wind, or ice (usually in the form of a glacier). If the wind is dusty, or water or glacial ice is muddy, erosion is taking place.

# data[].attributes.body
A topographic map is a map illustrating the topography or shape of the land surface

# data[].attributes.body
Chemical breaks down rocks and forms new minerals without changing their composition, Chemical breaks them down by making new minerals at the suface of the earth.

# data[].attributes.body
the earth climate determines its landscapes we see around the world.

# data[].attributes.body
Igneous rocks are made by melted rock, Sedimentary are made by mineral crystals of different sizes.

# data[].attributes.body
We can idenifty minerals by there luster, hardness, color, streak, specific gravity, cleavage, fracture, and tenacity.

# data[].attributes.body
we identify minerals by their luster, hardness, color, streak, specific gravity, cleavage, fracture, and tenacity.

# data[].attributes.body
Sediments sort themselves in a stream by deposition and they sort from size and weight

# data[].attributes.body
We can identify rocks by the texture, color, size and weight and many more catergories b

# data[].attributes.body
When erosion goes on the minerals that drop from the landscape would then come together and connect with each other and make new landscape

# data[].attributes.body
We understand that landscapes are formed by tectonic plates clashing and weathering.

# data[].attributes.body
Deforestation, overgrazing, development, and road construction all expose soil and sediments on the earth's surface, resulting in increased erosion.

# data[].attributes.body
Shape, Hardness, Luster, and color.

# data[].attributes.body
they sort themselves out by deposition in sizes and weight.

# data[].attributes.body
One rock can become another by the rock cycle or an example heat and pressure can change a sedimentary rock to a metamorphic rock

# data[].attributes.body
We can identify them by their luster and hardness

# data[].attributes.body
The weather sometimes can affect the shaping, for example disasters like earthquakes, flooding, ETC.

# data[].attributes.body
A topographic map is a map illustrating the topography or shape of the land surface. Topographic maps show the locations and form of hills, valleys, streams, and other features as well as many man-made landmarks. They illustrate the shape and elevation of surface features by the use of contour lines

# data[].attributes.body
We can identify rocks by the texture, color, patterns, and weight, and materials ETC.

# data[].attributes.body
The makeup of soil and the the benefits is that it allows plants to recycle their nutrients, hold onto the fresh water, and provide a home for the organisms.

# data[].attributes.body
A rock can become another via weathering, the rock cycle, small things like heat, etc.

# data[].attributes.body
Chemical weathering breaks down rocks by forming new minerals that are stable at the Earth's surface.

# data[].attributes.body
Igneous rocks are created by the melting of rock deep within the Earth. Sand, silt, dead plants, and animal skeletons combine to form sedimentary rocks. Metamorphic rocks are created from other rocks that have been altered underground by heat and pressure.

# data[].attributes.body
crystallization, erosion and sedimentary and metamorphism.

# data[].attributes.body
We identify them by their luster and hardness

# data[].attributes.body
they are sorted out from size and weight

# data[].attributes.body
Luster and Hardness

# data[].attributes.body
tectonic plates movement

# data[].attributes.body
The texture, color, patterns, and weight, and materials ETC.

# data[].attributes.body
Rock Cycle

# data[].attributes.body
A topographic map is a map that uses contour lines to try and remake the elevation of a landscape

# data[].attributes.body
They are usually separated by size and weight, They are also separated by velocity of the water stream.

# data[].attributes.body
It's a map that uses countor lines to represent what the landscape would look like

# data[].attributes.body
so erosion can affect the surface of the earth because of excessive amount of it leads to loss of soil and other damage it dose to the ecosystems.

# data[].attributes.body
How does erosion that lead the formation of different landscapes by how the valley shape.

# data[].attributes.body
Earth's processes and human activities change the surface of the earth because it leads to loss of soil and damages the earth's ecosystems. Human activity like housing, machines using gas, planting and other things change the makeup of the earth like the soil and the trees as well as the air we breathe in

# data[].attributes.body
contour lines connect all the points on the map

2.Steep Terrain

3.Gradual Slope

4.Peak

5.Scale

# data[].attributes.body
By erosion the earthś surface changes by Deforestation, overgrazing, construction, and road building often expose soil and sediments and lead to increased erosion.

# data[].attributes.body
Igneous rocks are formed from melted rock deep inside the Earth. Sedimentary rocks are formed from layers of sand, silt, dead plants, and animal skeletons. Metamorphic rocks formed from other rocks that are changed by heat and pressure underground.

# data[].attributes.body
Landscape is formed by tectonic plate

# data[].attributes.body
a 3d map

# data[].attributes.body
Sediments are sorted out from size and weight

# data[].attributes.body
the soil has dead animals and insects and that help crops grow.

# data[].attributes.body
The action of erosion can create an array of coastal landscape features. For example, erosion can bore holes that form caves. When water breaks through the back of the cave, it can create an arch. The continual pounding of waves can cause the top of the arch to fall, leaving nothing but rock columns called sea stacks.

# data[].attributes.body
Rock Cycle, Heat and high levels of pressure.

# data[].attributes.body
We can identify rocks based on small factors like color, fracture, density, features like glass, etc.

# data[].attributes.body
It is constantly moving and changing, transforming landscapes and landforms. The characteristics of most places are influenced by a combination of environmental processes, such as flooding and earthquakes, and human processes, such as mining and construction of cities.

# data[].attributes.body
its a map that gives a 3d version of a map that uses contour lines to show what the landscape looks like

# data[].attributes.body
Luster and hardness

# data[].attributes.body
Size and Weight

# data[].attributes.body
Erosion can affect the surface of the earth because and excessive amount of it leads to loss of soil and other damage to the ecosystems.

# data[].attributes.body
Sedimentary, Igneous and Metamorphic rocks shape our Earth by sedimentary is made of sand, metamorphic is made by heat and pressure and igneous is made up of metlted rock from inside of the earth

# data[].attributes.body
It separates sediments by size and weight, with the largest sediments going first because they require a lot of velocity, the medium-sized ones coming second because they require a lot less energy, and the smallest sediments coming last since they require little to no velocity.

# data[].attributes.body
sedimentary rocks- are made of layers of sand, metamorphic rocks are made up of other rocks that are change by heat and pressure underground. Igneous rocks- was formed from melted rock deep inside.

# data[].attributes.body
Landscape is formed by tectonic plate movement

# data[].attributes.body
by their features like luster and hardness

# data[].attributes.body
De-aijanee
Stream deposits are usually poorly sorted because the energy (velocity) in a stream varies with position in the stream and time.

# data[].attributes.body
luster and the hardness

# data[].attributes.body
The color,shape,size and texture

# data[].attributes.body
By size and wieght

# data[].attributes.body
we Identify rock by the layers and the texture.

# data[].attributes.body
A topographic map is a map that uses contour lines to try and replicate what the elevation of the landscape looks like

# data[].attributes.body
It sorts by size and weight

# data[].attributes.body
Color
Shape
Size
Streaks
Texture
Hardness
Type

# data[].attributes.body
The rock cycke

# data[].attributes.body
Mechanical weathering breaks rocks into smaller pieces without changing their composition.Chemical weathering breaks down rocks by forming new minerals that are stable at the Earth's surface.

# data[].attributes.body
texture, color, hardness, and shape

# data[].attributes.body
Once erosion happens, the rocks/materials that drop from it would then come together on a surface and connect with each other over time which then causes new forms of landscapes.

# data[].attributes.body
De-Aijanee
rock cycle

# data[].attributes.body
It sorts by size and weight, the biggest sediments go first because it needs a lot of velocity to carry them, the medium sized ones go second because it requires a lot less energy to carry them and the smallest sediments go last because little to no velocity is needed to carry them.

# data[].attributes.body
The weather plays a big role in shaping the landscapes we see around the world

# data[].attributes.body
the looks
durability
streaks
color
shape
texture

# data[].attributes.body
The Texture of the rock and the color of it

# data[].attributes.body
De-Aijanee
Erosion is a natural process, though it is often increased by humans' use of the land. Deforestation, overgrazing, construction, and road building often expose soil and sediments and lead to increased erosion. Excessive erosion leads to loss of soil, ecosystem damage, and a buildup of sediments in water sources.

# data[].attributes.body
We can identify minerals using hardness, luster, sometimes color and clevage.

# data[].attributes.body
rock cycle, heat, and pressure

# data[].attributes.body
Most minerals can be characterized and classified by their unique physical properties: hardness, luster, color, streak, specific gravity, cleavage, fracture, and tenacity.

# data[].attributes.body
Luster and hardness

# data[].attributes.body
it is formed by the Tectonic Plate.

# data[].attributes.body
A topographic map is a map illustrating the topography or shape of the land surface.

# data[].attributes.body
the rock cycle