The Earth’s surface changes over time due to weathering and erosion.

The Earth’s surface changes over time due to weathering and erosion.

The Earth’s surface is always changing!

WeatheringThe breakdown do the materials of Earth’s

crust into smaller pieces.

Water causes weathering

What evidence of weathering do you see

in this picture?

Ice causes weathering

Describe how ice causes weathering?

Temperature changes cause weathering.

Why did the outer layer of the rock crack?

ErosionThe process by which water, ice, wind or gravity

moves fragments of weathered rock and soil.

Where did the forces of erosion remove

material?

Erosion is Movement of Sediment!

• The process known as Erosion is gradually wearing down the surface of the earth.

• Erosion moves weathered rock and soil (sediment)  from one place to another.

• Erosion carves the Earth's surface creating canyons, gorges, and even beaches.

• Erosion also acts below the surface creating caves.

Which force of erosion carved this feature?

Be specific!

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

Water Causes Erosion• runoff, rivers and, streams

Water causes Erosion

When 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.

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 ErosionGlaciers 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

How much erosion takes place is determined by the:

• **Sum (Glaciers are

massive!)

• Slope• Speed• Surface

Gravity causes erosion

landslide clip.mpeg

Creep, Slump, Landslides, Mudslides, and Avalanches.

These are examples of mass movement (or called mass wasting)

Slower Faster

Gravity causes Erosion

How much erosion takes place is determined by the:

• 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

Where 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 8million 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.