Hank, Earth's Changing Surface Flashcards
Landforms
A part of the Earth’s surface that has a unique shape.
It was created by nature.
Most changes in the landscape of our Earth have occurred over
_________________________
Hundreds, thousands or millions of years.
Sediment
Small rocks, pebbles or sand.
Weathering
Breaks rocks and sediments into smaller pieces.
Abrasion
When rocks and sediment grind against each other and break down into smaller pieces.
Erosion
Gradual movement of sediment from one place to another.
Maybe moved by water, glacier or wind.
Deposition
Gradual build-up of eroded sediment.
Like a sandbar or a beach.
How can water, wind and ice cause erosion and deposition.
After sediment is eroded by moving water, wind or ice
Wind blows over beaches and sand dunes. Glaciers creep slowly down mountainsides.
Source of a river
Where a river begins.
Like a spring or melting mountain snow.
Riverbanks
The sides of a river.
Mouth of a river.
Where a river meets another body of water.
Like a lake, another river or the ocean.
Delta
A landform at the mouth of a river.
Made by moving water has deposited silt, sand, soil and rocks.
4 factors that shape a river.
- Slope of the land.
- Speed of the water.
- Hardness of the Earth’s surface.
- Amount of water.
Slope
How steep the land is that water is flowing down.
Glacier
A huge mass of moving ice.
Conditions that form a glacier.
- Lots of snow.
- Cold climate all year.
- Built over hundreds of thousands of years.
- When big enough, gravity makes it flow downhill.
How much do glaciers move?
1-2 inches per day
What causes a glacier to move?
Gravity and weight
The bottom of the ice melts and gets slippery.
How do glaciers weather rock and mountains?
Glaciers pick up rock as they move down mountains, they cause abrasion, polish the rock, and cut long scratches.
Glacial striations
Cuts and long scratches glaciers make in rocks.
Moraines
Glaciers can push big piles of rock and sediment into mounds and hills along their sides and in front of them.
Lakes often form behind moraines when glaciers melt.
Erratics
Large rocks or boulders carried along by glaciers and then left behind in strange places.
How are glacial valleys different from river valleys?
River valleys have a narrow V shape.
Glacial valleys have a wide U shape.
Why are people only partially right when they think landforms are shaped by the wind?
Landforms like Hoodoos were shaped by wind AND water.