ECS Chapter 3 Agents of Erosion Erosion The

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ECS Chapter 3 Agents of Erosion

ECS Chapter 3 Agents of Erosion

Erosion • The movement of sediment from one location to another by: • Wind

Erosion • The movement of sediment from one location to another by: • Wind • Water • Waves • Glaciers • Gravity

Gravity Erosion • Gravity is the force that pulls objects down toward the center

Gravity Erosion • Gravity is the force that pulls objects down toward the center of the Earth • Gravity will pull earth, water, weathered rocks…. downhill

Gravity Erosion landslides, mudslides, creep, and slump (earthflow)

Gravity Erosion landslides, mudslides, creep, and slump (earthflow)

LANDSLIDE- gravity pulls loose sediment downhill A landslide destroyed part of a town near

LANDSLIDE- gravity pulls loose sediment downhill A landslide destroyed part of a town near San Salvador, El Salvador, in 2001. An earthquake caused the landslide. http: //www. youtube. com/watch? v=XS 4 o 7 annpe. U&safety_mode=true& persist_safety_mode=1

Mudflow The torrent of mud and debris that swamped U. S. 30 west of

Mudflow The torrent of mud and debris that swamped U. S. 30 west of Clatskanie last week had its origin on clear-cut slopes logged by Oregon State's College of Forestry, the Oregonian reports this morning. The collapses on OSU's land put the state's top forestry institution face to face with longstanding concerns that logging can increase the risk of landslides, especially on steep slopes.

http: //www. youtube. com/watch? v=Id. Vi. Balpik. Y&safety_mode=true&persist_safety _mode=1 Earth movers shovel the mud

http: //www. youtube. com/watch? v=Id. Vi. Balpik. Y&safety_mode=true&persist_safety _mode=1 Earth movers shovel the mud and try to relevel the highway after mudslides occurred during a rainstorm. http: //www. youtube. com/watch? v=dpq 1 w. E 7 t 5 mc&NR=1&s afety_mode=true&persist_safety_mode=1

Creep- the slow movement of soil downhill by gravity erosion. You won’t see it

Creep- the slow movement of soil downhill by gravity erosion. You won’t see it occur, but you will see its effects A creep takes place when the entire side of a hill or mountain move downward under the weight of gravity, very slowly, usually much less than one inch per year.

Slump-the gravity erosion of a massive ‘chunk’ or amount of soil all at one

Slump-the gravity erosion of a massive ‘chunk’ or amount of soil all at one time http: //vide o. yahoo. c om/watch/ 1794382/5 933084 Review

Water Erosion • Moving water can move loose sediment to http: //w a new

Water Erosion • Moving water can move loose sediment to http: //w a new location ww. you • Rivers…streams…gullies…. all start as a tube. co m/watc h? v=M single raindrop. Raindrops become…. . Runoff that continues to flow downhill… Fp. CJsc _k 64&s afety_ mode=t rue&pe rsist_sa fety_m ode=1

Runoff cuts RILLS into the soil as the moving water carries away the loose

Runoff cuts RILLS into the soil as the moving water carries away the loose sediment…. . Large rills are called GULLIES. During a rainstorm and for a short time after, they stay filled with runoff water, but soon will dry up….

Gullies that drain together and empty into larger gullies that do not dry up

Gullies that drain together and empty into larger gullies that do not dry up when the rains stop are called streams or creeks….

Streams continue to carry runoff down hill and several will empty into one large

Streams continue to carry runoff down hill and several will empty into one large RIVER. http: //www. youtube. co m/watch? v=j_Bh. QGkd u 3 A&safety_mode=tru e&persist_safety_mod e=1

Niger River, Africa Dry season Rainy season During the rainy season, the water rises

Niger River, Africa Dry season Rainy season During the rainy season, the water rises fill the view above almost border to border, but during the dry it is little more than a trickle. This half of the bed can be crossed on foot without getting a shoe wet, while the other side is less than 20 m wide in places.

Millions of rills, gullies, and streams may drain to fill a river and those

Millions of rills, gullies, and streams may drain to fill a river and those smaller rivers may continue to drain downhill and fill larger rivers. This is the Hudson River with several of its TRIBUTARIES: the Mohawk River near Troy, the Hoosic River near Still water, the Batten Kill near Schuylerville, ….

Erosion Landforms- landforms created when sediment is carried away by moving water. • •

Erosion Landforms- landforms created when sediment is carried away by moving water. • • • River valleys Waterfalls Floodplains Meanders Oxbow lakes River Valley Waterfall Meander Floodplain

Moving water erosion • How/why do waterfalls form? http: //www. cla sszone. com/b ooks/earth_sci

Moving water erosion • How/why do waterfalls form? http: //www. cla sszone. com/b ooks/earth_sci ence/terc/cont ent/visualizati ons/es 1305 page 01. c fm? chapter_n o=visualization

Moving water erosion • How do meanders and oxbow lakes form? On the outside

Moving water erosion • How do meanders and oxbow lakes form? On the outside of the turn, the river is moving fasted and causing the most erosion. On the inside of the turns, the water slows down and deposits some of the sediment it is carrying. **An oxbow lake is a meander that has been cut off from the river**

Deposition Landforms created by moving water Alluvial fansediment deposited at the bottom of a

Deposition Landforms created by moving water Alluvial fansediment deposited at the bottom of a mountain stream Nile River Delta- sediment deposited at the mouth of a river http: //www. learn 360. com/Show. Video. as px? ID=146410

Groundwater: water moving underground can erode soil away Guatemala sinkhole, 2010 Guatemala sinkhole, 2007

Groundwater: water moving underground can erode soil away Guatemala sinkhole, 2010 Guatemala sinkhole, 2007 Sinkholes can occur when underground rocks that can be dissolved by water- such as salt, gypsum, and limestone— are inundated. The removal of groundwater can also leave gaps underground that can lead to sinkholes.

Glacier Erosion- sediment frozen to the bottom of glaciers moves with the glacier •

Glacier Erosion- sediment frozen to the bottom of glaciers moves with the glacier • Glacier- slow moving mass of ice that forms where more snow falls then melts (in the mountains, near the poles) • Valley glaciers -in mountain valleys • Continental glaciers -cover large areas of continents Continental glaciers reach thickness of almost 10, 000 feet and completely flatten the topographic features

Glacier Erosion Landforms Glaciers that form in the mountains are pulled slowly downhill by

Glacier Erosion Landforms Glaciers that form in the mountains are pulled slowly downhill by gravity. As they move they cut a valley. A glacial trough is what is left behind when a glacier carries away sediment and cuts sheer cliffs along the walls of the valley.

Glacier Erosion Landforms Kettle lakes in south Alaska Beautiful Villages along the Norwegian Coast

Glacier Erosion Landforms Kettle lakes in south Alaska Beautiful Villages along the Norwegian Coast , fjords coastlines cut by glaciers Rochester, NY Rock grooves: glacial abrasion Finger Lakes, New York combination of glacial abrasion and meltwater flow

Glacier Deposition Landforms Morrainesglacial sediment at the end and sides of a glacier Erratics-

Glacier Deposition Landforms Morrainesglacial sediment at the end and sides of a glacier Erratics- Large, deposited by glacier, boulders and rock formations that do not geologically match the surrounding rock

Umpire Rock in Central Park, NYC…deposited by glaciers during the last Ice Age… 10,

Umpire Rock in Central Park, NYC…deposited by glaciers during the last Ice Age… 10, 000 yrs ago. Look at the map of the last Ice Age in your text…. Long Island is the till(sediment) left by the glaciers…. a terminal morraine…a deposit at the end of a glacier.

Melting Polar Ice Caps. . leaving behind glacial landforms

Melting Polar Ice Caps. . leaving behind glacial landforms

1989 2009 Mt. Kilimanjaro in Africa-15, 000 ft high 1989

1989 2009 Mt. Kilimanjaro in Africa-15, 000 ft high 1989

Alaska’s melting valley glaciers

Alaska’s melting valley glaciers

K 2, Pakistan-2 nd highest mountain on Earth A critically important Himalayan glacier that

K 2, Pakistan-2 nd highest mountain on Earth A critically important Himalayan glacier that provides 90 percent of Pakistan’s agricultural irrigation water is now predicted to disappear by 2035. And hundreds of millions of people in India, China and Nepal could face water shortages because of other melting glaciers in the Himalayas, according to a World Wildlife Federation.

Wave Erosion • Wave erosion occurs on the shores • Waves can weather, erode

Wave Erosion • Wave erosion occurs on the shores • Waves can weather, erode and deposit sediment Boulders were set at the base of the Crashing waves can reshape cliff to slow down wave erosion shorelines beneath campus buildings.

Waves • Erosion landforms Sea cliffs, sea caves, sea arches, sea stacks… • Deposition

Waves • Erosion landforms Sea cliffs, sea caves, sea arches, sea stacks… • Deposition landforms Beaches are deposits of weathered sediment near shoreline The type of rock weathered determines the makeup of the beach

Wind Erosion • Wind has the greatest effect in the deserts • Deflation is

Wind Erosion • Wind has the greatest effect in the deserts • Deflation is the process of wind moving sediment (Think air coming out of a deflating balloon) • Sand dunes and Loess deposits are two wind landforms

Sand dunes All it takes is a bit of breeze (16 kilometers/hour or 10

Sand dunes All it takes is a bit of breeze (16 kilometers/hour or 10 miles/hour) to put fine sand in motion. Once sand begins to pile up, ripples and dunes can form. Wind continues to move sand up to the top of the pile until the pile is so steep that it collapses under its own weight. The repeating cycle of sand inching up the windward side to the dune crest, then slipping down the dune’s slip face allows the dune to inch forward, migrating in the direction the wind blows.

Sand dunes Made of slightly larger pieces of sand, dunes are located in deserts.

Sand dunes Made of slightly larger pieces of sand, dunes are located in deserts.

Loess deposits Made of finer sand, loess deposits are often found far away from

Loess deposits Made of finer sand, loess deposits are often found far away from deserts. Loess is fine silt deposited by fierce wind storms from distant locations