ErosionErosion

• The process by which water, ice, The process by which water, ice, wind or gravity moves fragments of wind or gravity moves fragments of rock and soil.rock and soil.

Water ErosionWater Erosion

• Rivers, streams, and runoffRivers, streams, and runoff

Ice ErosionIce Erosion

• GlaciersGlaciers

Wind ErosionWind Erosion

Mass Movements Mass Movements (Gravity)(Gravity)

• Landslides, mudslides, slump and Landslides, mudslides, slump and creepcreep

landslide clip.mpeg

Erosion LabErosion Lab• Station 1. Demonstrates beach erosion. Using a pan, Station 1. Demonstrates beach erosion. Using a pan,

make a sand pile at one end and pour water at the make a sand pile at one end and pour water at the other end. Slide the pan back and forth to create wave other end. Slide the pan back and forth to create wave movement. Record observations. movement. Record observations.

• Rebuild the beach. Design a “jetty” or dam to prevent Rebuild the beach. Design a “jetty” or dam to prevent erosion; repeat and record results.erosion; repeat and record results.

• Station 2: Place sand in a small bowl and blow gently Station 2: Place sand in a small bowl and blow gently to move the sand. Record observations.to move the sand. Record observations.

• Station 3: Place a pile of ice cubes (glacier) on a Station 3: Place a pile of ice cubes (glacier) on a mound of dirt. Observe and record what happens as it mound of dirt. Observe and record what happens as it melts.melts.

• Discussion Questions:Discussion Questions:• How does erosion occur?How does erosion occur?• What is the result of each type of erosion?What is the result of each type of erosion?

Deposition Deposition • When soil and rocks When soil and rocks

are eroded, they are are eroded, they are placed (deposited) in placed (deposited) in a new location. a new location.

• When this happens, it When this happens, it is called is called ““depositiondeposition”.”.

• Deposition is a Deposition is a constructive force. It constructive force. It builds or creates new builds or creates new landforms and landforms and features, such as a features, such as a shoreline, beach, and shoreline, beach, and river deltas.river deltas.

DepositionDeposition

• Beach/ShorelineBeach/Shoreline

DepostionDepostion

• Formation of delta:Formation of delta:

DepositionDeposition• Formation of Formation of

winding winding (meandering) (meandering) streams and oxbow streams and oxbow lakes.lakes.

The Mighty MississippiThe Mighty Mississippi• Welcome to the Mississippi River. It is the longest river in Welcome to the Mississippi River. It is the longest river in

the world -- four thousand three hundred miles.the world -- four thousand three hundred miles. It starts in It starts in Minnesota and continues south past New Orleans before Minnesota and continues south past New Orleans before flowing into the Gulf of Mexico. A common nickname for flowing into the Gulf of Mexico. A common nickname for the Mississippi River is "Old Man River". Rivers are longer the Mississippi River is "Old Man River". Rivers are longer

than they are wide.than they are wide.     

FormationFormation

• The Mississippi River basin was formed by The Mississippi River basin was formed by glaciers,glaciers, moving and melting millions of years moving and melting millions of years ago, which left in their wake sometimes miles-ago, which left in their wake sometimes miles-wide floodplains, that still fill up occasionally, wide floodplains, that still fill up occasionally, covering towns, roads, farms, and everything covering towns, roads, farms, and everything else that might stand in the way of its mighty else that might stand in the way of its mighty waters. waters.

GlaciersGlaciers• Newly fallen snow is about 80 percent air. Through some melting, evaporation, and Newly fallen snow is about 80 percent air. Through some melting, evaporation, and

refreezing, the light, fluffy snow turns into small, round granules called firn. If therefreezing, the light, fluffy snow turns into small, round granules called firn. If the• firn remains on the ground for about one year, it will reduce to 50 percent air.firn remains on the ground for about one year, it will reduce to 50 percent air.• When additional snow, along with dust, volcanic ash, and other air-depositedWhen additional snow, along with dust, volcanic ash, and other air-deposited• substances layer on top, the firn is compressed and changes into solid ice. Thissubstances layer on top, the firn is compressed and changes into solid ice. This• glacial ice is denser—composed of less than 20 percent air.glacial ice is denser—composed of less than 20 percent air.

• As the ice sheet thickens, the force of gravity causes it to move. Ice moves byAs the ice sheet thickens, the force of gravity causes it to move. Ice moves by• changing shape or by slipping and shifting along cracks in the ice sheets. Likechanging shape or by slipping and shifting along cracks in the ice sheets. Like• water, ice seeks the lowest levels and flows downhill. The ground beneath thewater, ice seeks the lowest levels and flows downhill. The ground beneath the• glacier weakens due to the downward pressure of the ice and constant waterglacier weakens due to the downward pressure of the ice and constant water• saturation. This ground breaks off and moves with the flow of ice, EROSION, lifting saturation. This ground breaks off and moves with the flow of ice, EROSION, lifting

through periods of re-freezing and melting.through periods of re-freezing and melting.

• Scientists believe that glaciers have had a big role in shaping much of NorthScientists believe that glaciers have had a big role in shaping much of North• America, including the Mississippi River valley. They theorize that as the glaciersAmerica, including the Mississippi River valley. They theorize that as the glaciers• developed, they picked up and carried gravel and even huge boulders (erosion). Thesedeveloped, they picked up and carried gravel and even huge boulders (erosion). These• varying sizes of debris carved out U-shaped valleys. varying sizes of debris carved out U-shaped valleys.

• As the glaciers melted, rivers flooded and eroded, and more rocks and soil were carried As the glaciers melted, rivers flooded and eroded, and more rocks and soil were carried away. The sediments soon are dropped (away. The sediments soon are dropped (depositeddeposited), forming channels, riverbeds, and ), forming channels, riverbeds, and banks.banks.

Erosion & DepositionErosion & Deposition• During seasonal floods in northern states, large amounts of silt During seasonal floods in northern states, large amounts of silt

and other soil sediments were extracted and sent flowing down and other soil sediments were extracted and sent flowing down the river. During its journey downstream, the rushing water the river. During its journey downstream, the rushing water took even more silt and soil from the river’s banks.   All of these took even more silt and soil from the river’s banks.   All of these materials traveled all the way down until they reached the edge materials traveled all the way down until they reached the edge

of the continental shelf at the end of Louisiana’s coast.of the continental shelf at the end of Louisiana’s coast.

DeltaDelta• Over time, the sediments spread over large areas in a continuous Over time, the sediments spread over large areas in a continuous

flow. The continuous stream of silt and other land-making materials flow. The continuous stream of silt and other land-making materials began to overlap each other. In due time, the materials started to began to overlap each other. In due time, the materials started to get higher and higher until the land began to peak out of the water. get higher and higher until the land began to peak out of the water.

• After this land emerged, it kept growing in size until it built up too After this land emerged, it kept growing in size until it built up too high for the river to continue flowing in that particular direction. high for the river to continue flowing in that particular direction. The Mississippi River then started to revert its flow in a different The Mississippi River then started to revert its flow in a different direction, doing all it could to spill into the Gulf of Mexico. This direction, doing all it could to spill into the Gulf of Mexico. This process of blocking and changing direction of the Mississippi kept process of blocking and changing direction of the Mississippi kept occurring until it reached its present location. Today, there is a occurring until it reached its present location. Today, there is a huge delta that was created by the changing course of the huge delta that was created by the changing course of the Mississippi River.Mississippi River.

Where is the Mississippi Where is the Mississippi River?River?

• It is in the central part of the United States. It is in the central part of the United States.

• It starts in Minnesota, and flows south to the It starts in Minnesota, and flows south to the

Gulf of MexicoGulf of Mexico. .

Mississippi RiverMississippi River

Map and river basinMap and river basin

A little Big River historyA little Big River history•

The Mississippi has a unique history. The North American The Mississippi has a unique history. The North American Indians called it “Messipi” which means “Big River”. The Indians called it “Messipi” which means “Big River”. The first non American Indian man to reach the river was first non American Indian man to reach the river was Hernando de Soto in 1541. He called the river “Rio de Hernando de Soto in 1541. He called the river “Rio de Espiritu Santo” or “River of the Holy Spirit”. In the 1600s, Espiritu Santo” or “River of the Holy Spirit”. In the 1600s, the French discovered the river and claimed the entire river the French discovered the river and claimed the entire river for France. The French called the river “Louisiana” named for France. The French called the river “Louisiana” named after their king Louis XIV.after their king Louis XIV.

• In the two hundred years that followed, the United States In the two hundred years that followed, the United States became a nation and claimed the area for itself. The became a nation and claimed the area for itself. The Mississippi and its connecting rivers became major Mississippi and its connecting rivers became major transportation routes. People, goods, livestock, and timber transportation routes. People, goods, livestock, and timber were transported to towns that were springing up all along were transported to towns that were springing up all along the river. The land surrounding the river was very fertile the river. The land surrounding the river was very fertile and was used to grow crops and raise livestock.and was used to grow crops and raise livestock.

Did You KnowDid You Know• Today, the Mississippi is still an important part of life in the Today, the Mississippi is still an important part of life in the

United States. Over 12 million people rely on the river for United States. Over 12 million people rely on the river for their daily drinking water and the river is still used for their daily drinking water and the river is still used for transportation and commerce. The flow of water in the river transportation and commerce. The flow of water in the river is regulated by a series of 27 locks and dams on the upper is regulated by a series of 27 locks and dams on the upper Mississippi. Built in the 1930s, they were designed to Mississippi. Built in the 1930s, they were designed to maintain a channel for ships and barges to travel. The dams maintain a channel for ships and barges to travel. The dams make the river deeper and wider but do not stop the flow of make the river deeper and wider but do not stop the flow of water. water.

• Ocean going ships can move upstream as far as Baton Ocean going ships can move upstream as far as Baton Rouge, Louisiana and smaller ships and barges can go up Rouge, Louisiana and smaller ships and barges can go up stream as far as Minneapolis, Minnesota. stream as far as Minneapolis, Minnesota.

• Coal, petroleum products (gas and oil), sand, gravel, salt, Coal, petroleum products (gas and oil), sand, gravel, salt, chemicals, grain and livestock are transported along the chemicals, grain and livestock are transported along the river. Shipping at the lower end of the Mississippi includes river. Shipping at the lower end of the Mississippi includes iron, steel, rubber, paper, wood, and coffee. The headwaters iron, steel, rubber, paper, wood, and coffee. The headwaters segment is not used for shipping. The lakes that are formed segment is not used for shipping. The lakes that are formed by dams are used for recreational boating and fishing. by dams are used for recreational boating and fishing.

Fun FactsFun Facts• The Mississippi River is home to: The Mississippi River is home to: • 241 fish species 37 mussel species 45 amphibians 241 fish species 37 mussel species 45 amphibians

50 mammals 40% of the nation's migratory birds 50 mammals 40% of the nation's migratory birds • In In 2002 Martin Strel 2002 Martin Strel swam the entire length of the swam the entire length of the

river. river. • A raindrop falling in Lake Itasca would arrive at A raindrop falling in Lake Itasca would arrive at

the Gulf of Mexico in about 90 days the Gulf of Mexico in about 90 days • At the headwaters of the Mississippi, the average At the headwaters of the Mississippi, the average

speed of the water is near 1.2 miles per hour. At speed of the water is near 1.2 miles per hour. At New Orleans, the speed of the river is about 3 New Orleans, the speed of the river is about 3 miles per hour. miles per hour.

• At its headwaters, the Mississippi is less than 3 At its headwaters, the Mississippi is less than 3 feet deep. In New Orleans, it is over 200 feet deep. feet deep. In New Orleans, it is over 200 feet deep.

River Ecosystems River Ecosystems

• The Mississippi River, along with its lakes, The Mississippi River, along with its lakes, tributaries and wetlands provide a habitat tributaries and wetlands provide a habitat for hundreds of species of animals, fish and for hundreds of species of animals, fish and birds. The River is the largest continuous birds. The River is the largest continuous system of wetlands in North America. It has system of wetlands in North America. It has wetland, open water, and floodplain wetland, open water, and floodplain habitats. A large percent of North habitats. A large percent of North America's duck, goose, swan, and wading America's duck, goose, swan, and wading bird populations use the river every year as bird populations use the river every year as they migrate south for the winter they migrate south for the winter

Danger on the River Danger on the River Mississippi River, the river also has a dangerous Mississippi River, the river also has a dangerous

side. Flooding is the number one natural disaster in side. Flooding is the number one natural disaster in the United States. Most flooding on the Mississippi is the United States. Most flooding on the Mississippi is

caused by too much rain falling in too short an caused by too much rain falling in too short an amount of time. The water rises about the banks and amount of time. The water rises about the banks and flows into the land around it. Sometimes, dams and flows into the land around it. Sometimes, dams and levies can break causing flooding. The quick rising levies can break causing flooding. The quick rising muddy water destroys homes, businesses, crops, muddy water destroys homes, businesses, crops,

livestock and sometimeslivestock and sometimes even human life.even human life.

The River in Danger The River in Danger

• Hundreds of years of human use Hundreds of years of human use have changed the Mississippi River. have changed the Mississippi River. The locks and dams have changed The locks and dams have changed the natural course of the river and the natural course of the river and have affected the natural ecosystem. have affected the natural ecosystem. Much of the floodplains and Much of the floodplains and wetlands areas have been destroyed wetlands areas have been destroyed by farming and housing by farming and housing developments. developments.

More ProblemsMore Problems

• Water, full of pesticides, chemicals and Water, full of pesticides, chemicals and waste, runs into the river from cities waste, runs into the river from cities and farms. These changes have added and farms. These changes have added to flooding problems and cause to flooding problems and cause hypoxia. hypoxia. Hypoxia occurs when there is Hypoxia occurs when there is not enough oxygen available in the not enough oxygen available in the water for marine life to live. This is a water for marine life to live. This is a problem in the Gulf of Mexico where problem in the Gulf of Mexico where the water from the Mississippi ends up. the water from the Mississippi ends up.

An Important ResourceAn Important Resource

• The Mississippi River is a very The Mississippi River is a very important part of North America. It important part of North America. It is responsible for a more prosperous is responsible for a more prosperous economy and for a large percentage economy and for a large percentage of the ecology of the United States. of the ecology of the United States. The Mighty Mississippi deserves our The Mighty Mississippi deserves our respect and our attention as we respect and our attention as we search for ways to preserve the river search for ways to preserve the river and river basin for the future and river basin for the future

Mighty Mississippi Mighty Mississippi Review SheetReview Sheet

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