Changing Earth’s Surface---Worksheet packet Changing Earth’s Surface: 5. Gravity: a. pulls things towards the earth’s center b. causes landslides c. causes mass movements d. is a force of erosion 6. The most destructive kind of mass movement is creep. False 7. Mudflows and slump are especially likely in soils high in clay. True 8. Mass movement includes landslides: Mudflow, slump, creep---it doesn’t matter the order Increases in water cause large masses of land to slip and fall with gravity. 9. Landslide: Rock and soil slide quickly down a steep slope 10. mudflow: a mixture of water, rock, and soil moves rapidly downhill 11. Slump: Rock and soil suddenly slip down a slope in one large mass. 12. Creep: Rock and soil move very slowly downhill Water Erosion 1. Moving water is a major agent of erosion. 2. Water that moves over Earth’s surface when it rains is called Runoff. 3. Other than how people use the land, four factors that determine the amount of runoff in an area are: The amount of rain it receives, vegetation (plants there), type of soil, shape of the land 4. More runoff generally means less erosion. False Water Erosion Continued: (Bottom of second page...worksheets 106-107) 5. Rill: Water moving in tiny groove in soil after a rainstorm Gully: Water moving in a channel after a rainstorm Stream: Water continually flowing down a slope through its own channel River: Water flowing downhill in a large channel Rivers cause the greatest changes in the shape of the land because they have more water moving faster. 6. A stream that flows into a larger stream is called a(n) tributary. 7. The area of land from which a river and it’s tributaries collect water is the flood plain (watershed---before it floods, its called the watershed because it sheds water into the river. 8. VShaped valleys form when a river cuts between mountains. 9. Rivers develop meanders when rivers flow across easily eroded sediment and bend in a u shaped form 10. A meander that has been cut off from a river is called a(n) oxbow lake. 11. This is a picture. a. meander, b. oxbow lake, c. Waterfall, D. River, E. Flood plain/watershed, 12. 13. 14. 15. Two landforms created by deposits from rivers are oxbow lakes and meanders. Deposits on the flood plain is also an answer. An alluvial fan is a deposit of sediment that results as the river slows down when leaving a mountain. It is fan shaped. Sediments deposited where a river flows into an ocean or lake form a Delta. A river valley is made fertile when nutrients wash from the mountain range down in to the valley after a hard rain. Groundwater Erosion 16. Underground water is called Groundwater. 17. Unlike moving surface water, groundwater does not cause erosion. False 18. Groundwater causes chemical weathering of limestone by dissolving minerals in the rock and changing it’s composition. 19. Type of Deposit: Stalactite: Roof of a cave, forms when groundwater seeps into a cave and minerals collect as they drop from the ceiling. Stalagmite: Floor of a cave; groundwater dissolving through the roof of a cave dripping on the floor. Both stalactites and stalagmites form from deposits of minerals in the caves. They are different in that stalactites form on the roof of the cave, and stalagmites form on the floor of the cave. 20. An areal where sinkholes are common is said to have a karst topography. True Glaciers 1. Any large mass of ice that moves slowly over land is a glacier. 2. Continental glaciers are larger than valley glaciers, and spread out over a wide area. 3. ice ages are times in history when much of the land masses were covered with ice. 4. valley glaciers are generally long and narrow and usually move down valleys. 5. Two processes by which glaciers erode the land are plucking and abrasion. 6. Abrasion scratches bedrock. 7. Glaciers deposit the sediment they are carrying when they slow down. 8. Till: Mixture of sediments a glacier deposits on the surface 9. Moraine: Ridge formed at the edge of a glacier 10. Terminal Moraine: Ridge at the farthest point reached by a glacier 11. Drumlin: Long mound of till that is smoothed in the direction of the glaciers flow 12. Kettle: A small depression formed by a chunk of ice when it melts. 13. Cirque: bowl shaped hollow eroded by a glacier 14. Arete: sharp ridge separating two cirques 15. Fiord: Sea filled valley cut by a glacier in a coastal region. 16. Glacial erosion picks sediment up. Glacial Deposition drops it. Waves 1. The energy in waves comes from wind, moves water particles up and down, and moves across the water. 2. 3. 4. 5. 6. 7. 8. 9. 10. The part of the water that is affected by a wave in deep water is the surface. Waves approaching land begin to drag at the bottom and encounters friction. Waves are the major force of erosion along coasts. True Waves erode land by impact and abrasion (erosion & weathering) Part of the shore that sticks out into the ocean because it is made of harder rock is called the headland. Landforms created by wave erosion are wave cut cliffs, sea arches, sea stacks, and sea caves. An area of wave washed sediment along a coast is a beach. The process in which beach sediment is moved down the beach with the current is called longshore drift. Spits form when a longshore drift deposits sediment. Wind 1. A deposit of windblown sand is a sand dune. 2. Wind is the strongest agent of erosion. False 3. Wind is effective in causing erosion in deserts because the sand isn’t held in place by vegetation and blows easily. 4. Deflation is the main way wind causes erosion, it usually has a great effect on the land and it can create blowouts. 5. Abrasion by wind carried sand can polish rock and causes little erosion. 6. All the sediment picked up by wind eventually falls to the ground. True. 7. Wind carried sediment falls to the ground when the wind slows down. 8. Deposits formed by wind erosion and deposition include sand dunes and loess deposits. 9. Sand dunes have coarse grained sediments, loess has finer sediments, both are caused by wind erosion. 10. Loess can be found far from its source because it is fine and can be carried. Key Terms 1. Erosion is how sediment moves 2. Deposition is how sediment settles 3. Sediment is the small particles that move 4. Runoff is the water that runs over earth’s surface 5. Meanders are loop like bends in the course of a river 6. Abrasion is how rocks are polished 7. Deltas can be found where a river enters a lake 8. Headland sticks out into the ocean 9. Kettles are formed by a chunk of ice 10. Pits stick out in the water like a finger 11. Moraine is a ridge at the edge of a glacier 12. loess is a deposit of clay and silt 13. deflation is how most wind erosion occurs 14. tributary flows into a larger stream 15. oxbow is a kind of lake created by a river 16. sand dune is a deposit of wind blown sand.