Erosion and Deposition Table of Contents Mass Movement Water Erosion Glacial Erosion Wave Erosion Wind Erosion Human Activity and Erosion pg. 344-347 pg. 348-357 pg. 358-363 pg. 364-367 pg. 368-371 pg. 372-377

Mass Movement Cycle of Erosion and Deposition Erosion is the process by which weathered rock and soil, or sediment, is moved from one place to another. Deposition occurs when erosion deposits, or lays down, the sediment.

Mass Movement Mass Movement Gravity is the force that pulls objects downward (towards the Earth). Gravity also causes mass movement of sediment. It can occur rapidly or slowly. The different types of mass movement include landslides (when rock and soil slide quickly down a steep slope), mudflows (the rapid downhill movement of water, rock, and soil), slump (when rock and soil suddenly slips down a slop in one large mass), and creep (the very slow movement of sediment).

Match the Mass Movement type with the correct diagram. Mudflow Slump Landslide Creep

Glacial Erosion Glaciers are any large mass of ice that moves slowly over land. They can only form in areas where more snow falls than melts. Continental glaciers can flow in all directions as they move and they cover much of a continent or large island. Today, continental glaciers cover about 10% of Earth’s land. Valley glaciers are long, narrow glaciers that form in the valley of mountains. They can move at a rate of a few centimeters to a few meters a day. When glaciers move they pick up huge rocks and small sediment. Cuts and scratches, also called abrasions, in bedrock are evidence of glacial movement.

Glacial Erosion Valley Glaciers When glaciers recede, they leave behind evidence of their existence.

Energy in waves comes from the wind. Waves shape the coast through: Wave Erosion Wave Erosion Energy in waves comes from the wind. Waves shape the coast through: erosion by breaking down rock causing headland, sea arches, sea stacks, caves, and wave-cut cliffs. depositing sediment, forming coastal features such as beaches, sandbars, barrier beaches, and spits.

Wave Erosion Page 366-367 What are the different landforms called? Were they formed by erosion or deposition?

Wind Erosion Wind Erosion Wind can be a powerful force in shaping the land, especially where there are few plants to hold the soil in place. The wind causes erosion through deflation, the process by which wind removes surface material. It moves particles in three ways. Which of the words--fine, medium, or large--correctly begins each sentence?

Wind Erosion Wind erosion and deposition may form sand dunes. Sand dunes are where wind-blown sediment has build up. They can come in many shapes and sizes. Sand dunes move over time and are shaped according to the wind direction. Plant roots can help anchor dunes in one place.

Human Activity and Erosion Mining, logging, agriculture, and the development of land cause erosion and deposition. Strip mining is the process of scraping away vegetation and topsoil above minerals close to Earth’s surface. Clear-cutting is a process in which every tree in a large section of forest is cut down at once.

Water Erosion Factors Affecting Runoff When water moves over the land, it carries particles with it. This is called runoff. Runoff factors include the amount of rain in the area, the type of vegetation on the land, the soil type, the topography or shape of the land, and human usage in the area.

Water Erosion River Formation Rivers begin when many small streams come together (called tributaries) into a main river. As the river flows over flat land, or the flood plain, and slows down, meanders or loop-like bends in the river form. Sediment deposited where a river flows into an ocean or lake, also known as the river mouth, builds up a landform called a delta.

Water Erosion Oxbow Lakes In a meander, water on the inside of the bend flows slower than that of the outside which deposits sediment, increasing the side or shape of the meander. Sometimes oxbow lakes can form from a meander that has been cut off from a river.

Water Erosion Water Deposition Deposition creates landforms such as the Mississippi River delta.

Mississippi River Drainage Basin World’s 3rd largest watershed drainage basin Covers more than 1,245,000 square miles Includes all or part of 31 states and 2 Canadian provinces 41% of the United States

Human Activity and Erosion Mapping Louisiana Coastal Erosion Louisiana’s coast has lost about 55 square kilometers of wetlands per year over the last 50 years. It is predicted that an additional 1,127 square kilometers of land will be lost in the next 50 years.

Human Activity and Erosion Changing Wetlands The graph shows changes in coastal Louisiana wetland area over the past 6,000 years. Based on the data in the graph, what do you think might happen to the wetlands in the next hundred years?