Water’s Effects on Shaping the Earth’s Surface

10.4

Weathering

• The process of breaking down rock into smaller fragments

• Two main types:– Physical Weathering: physical means such as being

scratched by other rocks, not changing it’s composition

– Chemical Weathering: a chemical reaction causing the rocks to decompose or break down

Physical weathering

Chemical Weathering

Biological Weathering

• If physical weathering has occurred by an animal or plant: Biological weathering

Deposition

• Rocks and sediments are carried away eventually are DEPOSITED somewhere else

Examples: Sand dunes and Deltas

Note: deposition is also a term for a change of state from Gas to Solid

Caves, Sink holes and Karst• Carbon dioxide is released

from respiration• When rain water mixes

with Carbon dioxide or from carbon in organic material -> the water becomes slightly acidic

• Acidic rain water mixes with calcium carbonate in the ground which creates caves, sinkholes or karst

Karst

• An area with many sink holes

Erosion by water and ice

• Moving water– Fast moving rivers– Outside banks along the

rivers– Ocean bluffs by wave

action

Landslides

• Erosion by gravity

Check

• Give two examples of physical weathering– Ice or Frost Wedging and Erosion

• What forms when carbon dioxide mixes with water vapour?– Carbonic Acid (Acid rain)

Karst

• An area with many sinkholes.

• A sinkhole is an area where rock has been broken down by acidic ground water and it is close to the surface. Eventually over thousands of years, the ground above collapse.

• Vancouver Island and the Rocky Mountains have many Karsts– Carbonate rock that reacts with any acid in the ground

water.

Feature Carved by Glacier

Description

Arete Narrow ridge (high ground) between two cirques

Cirque Bowl-shaped valley at the head of a glacier

Fiord A narrow inlet of ocean between steep cliffs carved by glaciers

Hanging Valley U-shaped valley cut off by a bigger valley created by a larger glacier

Horn Pyramid-shaped peak located between three cirques

Deposited by water and iceFeature deposited by a Glacier

Description

Erratic Large boulder deposited on the ground by a glacier

Esker Winding ridge of material deposited by a stream running under a glacier

Moraine Ridge of rocky material deposited by a glacier. Moraines can be found at the sides and farthest advance of a glacier

Outwash Material deposited by water from melting glacier