Exploring Earth’s Surface 3 Exploring Earth’s Surface 3.2 Today the students will understand what the topography of an area includes, and what are the main types of landforms Chapter 3 Lesson 2

Lewis & Clark What were the names of the men who journeyed west in the early 1800’s? Historical Trivia: What US President commissioned their expedition? Thomas Jefferson (3rd President) What years were they gone? 1804 -1806 What main river did they travel west on? Columbia River

Key Questions What does the topography of an area include? What are the main types of landforms?

Topography the shape of the land determined by elevation, relief and landforms

Elevation the height above sea level of a point on Earth’s surface

Exploring Earth’s Surface Lewis & Clark’s Journey The route of the Lewis and Clark expedition crossed regions that differed greatly in elevation and relief. What were the highest and lowest points on their route? Highest Point – Lemhi Pass in Rocky Mountains: 8,000 feet! Lowest Point - St Louis (St. Charles, Missouri): 460 feet

Relief the difference in elevation between the highest and lowest parts of an area Flat/rolling land with low relief (Small difference in elevation) Huge mountains/ deep valleys with High Relief (great differences in elevation)

Landforms a feature of topography, such as a hill or valley, formed by the processes that shape earth’s surface

Plain landform made up of nearly flat or gently rolling land with low relief Coastal Plains From East and SE Coast Low elevation / low relief Interior Plains Lies away from the coast Broad interior plains of N.A. are called the Great Plains

Mountain land form with high elevation and high relief This is Mt. Hood near Portland, Oregon

Mountain Range group of mountains that are closely related in shape, structure, area and age

Plateau landform that has high elevation and a more or less level surface A plateau is rarely perfectly smooth on top.

Landform Regions a large area of land where the topography is made up mainly of one type of landform

The United States has many different landform regions The United States has many different landform regions. Identify Florida on the map. Classify it by landform region.

Mass Movement 3.3 Chapter 3 Lesson 3

Can you recall the cycle? What are the 3 main parts of the cycle that tear down and build up the earth? Weathering Erosion Deposition

Gravity the force that pulls everything toward the center of the earth It pulls rock down slope It can cause section of rocks to fall off cliffs It can cause the movement of large amounts of sediment

Mass Movement Processes that move large amounts of sediment downhill Mass movement can be rapid or slow Erosion and deposition both take place during a mass movement event

1. Landslide Occurs when rock and soil slide quickly down a steep slope

2. Mudflow The rapid downhill movement of a mixture of water, rock and soil Mudflows often occur after heavy rains in a normally dry area

3. Slump A mass of rock and soil suddenly slips down a slope Unlike a landslide, the material in a slump moves down in one large mass

4. Creep The very slow downhill movement of rock and soil. Often results from the freezing and thawing of water in cracked layers of rock beneath the soil

Mass Movement The different types of mass movement include landslides, mudflows, slump, and creep.