Erosion and Landforms Erosion and Landforms Key Question

Erosion and Landforms

Erosion and Landforms • Key Question: What is erosion and what are the types of erosion? • Initial Thoughts:

Evidence • Glue the student notes handout into your journal. • Take notes from the Power. Point Presentation.

Evidence • What is Erosion? • The process by which weathered rock and soil particles are moved from place to place. • What is Deposition? • The process by which weathered sediments are laid down in a new location creating new landforms.

5 Agents of Erosion There are five agents of erosion. • Gravity • Glaciers • Wind • Surface Water / Running Water • Ocean Shoreline / Ocean Waves

Gravity • Pulls rock and soil down a slope • Called Mass Movement • Rapid • Rockslides • Mudflow • Avalanche

Gravity Slow • Slump • Creep

Glaciers • Carry very large to very small debris • Most powerful agent • What do they deposit? • Form piles called moraines • Drumlins – little mounds • Glacial lakes • Kettle lakes • U-shaped valleys

Moraines

Drumlins Glacial lakes

Kettle Lakes U-shaped valleys

Glaciers

Wind • Removes loose material from the earth’s surface. • Amount of material carried depends on wind speed • Most active in deserts, deserts plowed fields, beaches • What does wind deposit? • Loess- layer of fine silt or sand • Dunes- mounds of sand

Loess

Dunes

Running Water • MAJOR CAUSE OF EROSION • When water moves it carries particle called the load • Speed of water determines the size of the load • Creates canyons and valleys • What do rivers create/deposit? • Deltas • Oxbow lakes • Flood plains

River Deltas

Oxbow Lakes

Flood Plains

Waves • Constantly erode and shape the shoreline. • What formations do waves create? • Sea cliffs • Sea stacks and caves

Sea Stacks

Sea Stacks & Cliffs

Cape Flattery, Olympic Peninsula Sea Caves

Waves What do waves deposit? • Beaches • Spits • Sand bars • Barrier Islands

Barrier Islands

Spits & Sandbars

Coral Islands • Lava from an underwater volcano builds up an island. Living organisms begin living around the shores of the island (polyps). • Volcano becomes inactive, sinks, coral dies, an island forms. • The formation is a hard rock-like material formed by the skeleton of marine polyps and sand (takes millions of years!)

Coral Islands • Usually forms a ring and partially or totally encloses a shallow body of water, or lagoon • Most are found in the Pacific Ocean

Limestone Deposits • Form underwater from the shells of dead animals • Takes millions of years!

Limestone Deposits

Oil/Coal Deposits • Plant matter accumulates at the bottom of a body of water (must be protected by from decomposition and oxygen exposure—usually gets covered by mud or an acidic water layer). Over millions of years, it forms into a hardened brownish black sedimentary rock.

Oil/Coal Deposits • Coal is a fossil fuel and is the largest source of energy and the largest source of carbon dioxide emissions • Coal is extracted from the ground by mining, either underground or in open pits.

Oil/Coal Deposits • Oil is generally formed from marine deposits and coal is generally formed from land vegetation.

Sources • http: //www. pbs. org/wgbh/nova/caves/form_bacteria. html

Analysis 1. List the causes of erosion. 2. Compare some major differences between the types of erosion.

Summary • What did you think about erosion before this lesson? • What did you learn about erosion from this lesson? (Minimum of 3 sentences!!!) • What are some further thoughts or questions you have about erosion?

Reflection • What is the difference between erosion and weathering? • What types of landforms are created by erosion?

Big Idea