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 PowerPoint Presentation.

Evidence

•What is Erosion?•The process by which weathered rock and soil particles are movedmoved from place to place.

•What is Deposition?•The process by which weathered sediments are laid downlaid 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•PullsPulls rock and soil down a slope•Called Mass MovementMass Movement

•Rapid•Rockslides•Mudflow•Avalanche

GravitySlow

• Slump• Creep

Glaciers•Carry very largelarge to very smallsmall debris

•Most powerful agent

•What do they deposit?•Form piles called morainesmoraines•Drumlins – little mounds•Glacial lakes•Kettle lakes•U-shaped valleys

Moraines

Drumlins

Glacial lakes

Kettle Lakes

U-shaped valleys

Glaciers

Wind•Removes looseloose material from the earth’s surface.

• Amount of material carried depends on wind speedwind speed

• Most active in desertsdeserts, plowed fields, beaches

•What does wind deposit?• Loess-Loess- layer of fine silt or sand• Dunes-Dunes- mounds of sand

Loess

Dunes

Running Water•MAJOR CAUSE OF EROSION

• When water moves it carries particle called the loadload.

• SpeedSpeed of water determines the size of the load• Creates canyonscanyons and valleys

• What do rivers create/deposit?What do rivers create/deposit?• Deltas• OxbowOxbow lakes• Flood plains

River Deltas

Oxbow

Lakes

Flood

Plains

Waves

•Constantly erode and shapeshape the shoreline.

• What formations do waves What formations do waves create?create?

•Sea cliffs•Sea stacksstacks and caves

Sea Stacks

Sea Stacks & Cliffs

Cape Flattery, Olympic Peninsula

Sea Caves

Waves

What do waves deposit?What do waves deposit?

•Beaches•Spits•Sand barsSand 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.

SourcesSources• 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