Weathering and erosion

True or False: The Earth’s surface has stayed the same for thousands of years

True or False: The Earth’s surface has stayed the same for thousands of years False The Earth’s surface is always changing!

Weathering and Erosion Wind Water Ice Gravity

Weathering
The breakdown do the materials of Earth’s crust into smaller pieces.
Weathering causes soil formation

Water causes weathering What evidence of weathering do you see in this picture?

Wind causes weathering What evidence of weathering do you see in this picture? Why wasn’t this mass of land weathered away?

Ice causes weathering Describe how ice causes weathering?

Erosion
The process by which water, ice, wind or gravity moves fragments of rock and soil.
What evidence of erosion do you see in this picture?

Erosion is Movement of Sediment !
This process, known as Erosion , is gradually wearing down the surface of the earth .
Erosion is the process by which weathered rock and soil (sediment) are moved from one place to another .
Erosion carves the Earth's surface creating canyons, gorges, and even beaches .
What do you think has caused this rock to look this way?

Wind Erosion
As the wind blows it picks up small particles of sand/sediment and blasts large rocks with the abrasive particles, cutting and shaping the rock.
The intensity of wind erosion is determined by:
Sum (amount)
Speed
Slope
Surface

Wind Erosion Creates sand dunes Greatest impact in deserts Removes fertile topsoil

Water Causes Erosion
runoff, rivers and, streams
Creates MOST of the changes in the Earth's landscape!

Water causes Erosion
W hen rain falls to the Earth it can evaporate, sink into the ground, or flow over the land as Runoff.
When it flows over land, erosion occurs.
Runoff picks up pieces of rock and "runs" downhill cutting tiny grooves (called rills ) into the land.
Rivers and streams are a constant flow of runoff- they constantly weather and erode!

Water causes Erosion
How much erosion takes place is determined by the:
Sum (amount)
Slope
Speed
Surface
Can you act increasing and decreasing the four S’s?

Ice Causes Erosion Glaciers wear down the landscape; by picking up and carrying debris that moves across the land along with the ice.

Ice Causes Erosion
Glaciers can pick up and carry sediment that ranges in size from sand grains to boulders bigger than houses.
Moving like a conveyor belt and a bulldozer, a single glacier can move millions of tons of material!

Ice Causes Erosion
**Sum (Glaciers are massive!)
Slope
Speed
Surface

Gravity causes erosion
Creep, Slump, Landslides, Mudslides, and Avalanches.
landslide clip.mpeg These are examples of mass movement (or called mass wasting) Slower Faster

Gravity causes Erosion
Sum
**Slope
Speed
**Surface

Plants CAN CAUSE weathering

Plants CAN PREVENT erosion

Deposition
Rock particles that are picked up and transported during erosion will ultimately be deposited somewhere else
Deposition is the process by which sediments (small particles of rock) are laid down in new locations.
Together, Erosion and Deposition build new landforms.
Deltas
Canyons
Meanders
Floodplains

Delta
W here rivers meet the ocean is called the mouth of the river. Soil and dirt carried by these rivers is deposited at the mouth, and new land is formed. The new, soil-rich land is known as a Delta

Canyons This simple animation provides you with a visualization of how the Colorado River has "downcut" into the rock layers of the Grand Canyon. How long it took to carve the Grand Canyon is debated by geologists. Some estimates are between 6 and 8 million years, which is very recent by comparison. Canyons are large valleys created by a river or stream.

Meanders Meandering streams wander side to side as they constantly seek out the lowest elevation. This constant motion creates a series of S-shaped “loops”.

Meanders Stream Velocity varies from one side to the other side of the “S”, resulting in erosion in some places and deposition of sediments in others.

Floodplains
Floodplains form along the banks of mid-order streams and larger rivers.
These are low-lying areas along the sides of a river channel that have regular times of heavy waterflow to cause the river to spill over and flood the land.

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Weathering and erosion

by lovenaces60 on Jul 27, 2010

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Weathering and erosion — Presentation Transcript