Incremental Changes Wind, Water, Ice

Incremental changes shape or sculpt the earths surface This is done by a combination of slow, step-by-step changes called weathering and erosion.

Weathering is the mechanical and chemical process that breaks down rocks from water, glacial ice, wind and waves

Types of Weathering Mechanical Chemical Biological

Mechanical Weathering This happens when rock is broken apart by physical forces, from water or wind. Since it is so cold here in Canada, rocks are broken down by water freezing in the cracks. Frozen water  expands

The effects of weathering by wind can be seen on this rock formation at the Paria Canyon in Arizona, USA Located in Victoria, Australia these limestone pillars called the, “twelve apostles” have been created by the action of waves crashing against the limestone pillars.

Chemical weathering This happens when water and oxygen react with the minerals in rocks to produce new minerals. Gases in the air + Water (rain or snow) + minerals  Acids Acids dissolve minerals in the rocks wearing them down

The effects of chemical weathering in particular acid rain can be seen on this close up of this statues face. The acid rain has reacted with the mineral grain of the rock which has over time caused cavities to form as well wearing away the definition of the facial features.

Biological weathering Is the wearing away of rocks by living things. The growing of large trees changes its surrounding

This image shows biological weathering taking place by a tree whose roots have grown within a rock face.

Erosion occurs when the pieces from weathering are transported from place to place.

Deposition is the process of these materials being laid down or deposited by wind, water and ice.

Weathering, Erosion and Deposition do not make or get rid of materials, it just moves to reshape the earths surface

Moving Water Rivers and Streams are one of the most powerful forces of erosion that changes the landscape

As rivers flow, they carry sediment: silt, mud and gravel particles When the sediments are deposited (put down) this process is called Sedimentation Sedimentation usually happens at the bottom of lakes, rivers and oceans

Running water also creates landforms called Fluvial Landforms

The powerful force of moving water causes erosion The powerful force of moving water causes erosion. The water wears down the rock and transports these particles to other places, and sometimes this happens very fast. Landslides are sudden and fast movements of rocks and soil down a slope

Glaciers A glacier is a moving mass of ice and snow Glaciers change the shape of our landscape by picking up rocks as they move and these rocks scrape and carve the bedrock. Bedrock is the layer of solid rock underneath the loose rock fragments that