Erosion Flashcards
What is the difference between weathering and erosion?
Weathering breaks the rock
Erosion takes the rock
What is the process of erosion (3 steps)
- weathering - rocks like mountains, cliffs and boulders are weakened
- Water and wind ERODE and take the smaller pieces of rock and sediments away
- They are deposited (dropped) in another place
What is erosion?
It is a natural process. It changes the earths surface over time
What are the 4 types of erosion
- water erosion
- Wind erosion
- Ice erosion
- Gravity erosion
What is examples water erosion?
- RAIN creating small rivers in dirt
- RIVERS breaking apart the rock or ground they flow through
- WAVES breaking rocks from cliffs or taking sand from beaches
- FLOODS destroying large areas of land
Why does running water cause water erosion?
Over thousands of millions of years the force of running water and GRAVITY move rocks and sediments downwards CARVING AND CUTTING through the landscape
How does running water make new landforms?
As the water runs, sediments are carried down by the river and deposited to make new landforms
What is a coastline
A coastline is formed when the land meets the sea.
Coasts are always changing.
How do waves cause erosion?
The PUSH and PULL of the tides and powerful waves erode the beaches and cliffs
What are the 2 types of wind erosion?
- Deflation
- Abrasion
What is wind deflation
Where wind picks up dust or loose particles and carries it away
What is abrasion?
Where the wind causes these flying particles to hit against places such as cliffs or rocks eroding them
What is carving wind?
The wind can create lots of different land forms especially in deserts
1. sand dunes
2. wave rocks
The wind can also create DUST storms
What causes ice erosion
Ice erosion is mainly caused by glaciers
What is a glacier?
Glaciers are large rivers of slowly moving ice
How do glaciers cause ice erosion?
Glaciers carve their way through and down mountains creating valleys or new mountain ranges
How does moving ice cause erosion?
- snow falls onto the mountain
- Snow hardens into solid ice to create a glacier
- Gravity pulls the glacier down and rocks fall down too
- Glacier melts as it reaches warmer air
What happened in the ice age?
Up until 12000 years ago most of the earth was covered in glaciers
As the ice melted new landforms were created.
What landforms were created after the ice age
- Fjords - inlet filled by sea water
- Plateau - high flat land
- U shaped Valley
- Ridge
What is gravity erosion?
When large rocks or a collection of rocks are pulled down cliffs and mountains by the force of gravity
Is Erosion fast or slow?
Erosion is normally SLOW.
But sometimes it is sudden
When is erosion SUDDEN
- Floods
- Landslides
- sand erosion
Where does erosion happen
It happens all over the world
What places are susceptable to erosion?
Places that have very little vegetation and are made up of soft materials like dirt, sand or chalky rock.
These places include
BEACHES, MOUNTAINS, DESERTS, RIVER BEDS
How have humans caused erosion?
- Cutting down trees and causing soil to loosen (DEFORESTATION)
- Using land for farming until the soil becomes dry and arid (DESERTIFICATION)
- Livestock like sheep and cows eating grass and causing the top soil to ERODE
How can humans control erosion?
- Plant new trees after the old ones are cut down
- move livestock around so grass can grow again
- Plant trees around crops
- Placing rocks or barriers on slopes
