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Bart Weather-Erosion
Question | Answer |
---|---|
What is Mechanical Weathering? | Breaking rocks apart by physical processes. |
What is Chemical Weathering? | Reactions of chemicals with minerals in rocks to dissolve or change them into different minerals. |
What are the effects of both kinds of weathering? | The surface of the Earth is changed. |
What are some causes of Mechanical Weathering? | Plant roots, digging(burrowing)animals, Rain, Wind, Expanding ice (ice wedging) |
What is ice wedging? | When water enters cracks in rocks then freezes the water expands and breaks the rock apart. |
What are some causes of Chemical Weathering? | Carbon dioxide plus water equals CARBONIC ACID, decaying plants give off organic acids, Iron plus oxygen and water equals OXIDATION |
How does carbonic acid weather rocks? | It will react with Calcite found in limestone to dissolve away rock creating caves and cave formations. |
How does climate effect weathering? | Cold climates where the temperature falls below freezing create mechanical weathering, warm, wet climates create organic and carbonic acid causing chemical weathering. |
What are the components of soil? | weathered rock, decayed organic matter, mineral fragments, water and air |
What factors affect soil formation? | climate (weather), slope of land, type of rock in area, type and amount of vegetation in area, length of time the rock has been weathering |
What is humus? | Dark colored decaying organic matter |
What purpose does humus serve in the soil? | It provides nutrients for the growth of plants. |
What are the layers of the soil profile? | A horizon, B horizon, and C horizon |
Which layer of the soil profile is also called topsoil? | The A horizon |
Describe the A horizon. | It can be covered by debris and organic material (plants) that will eventually become darkly colored humus that will help prevent erosion. |
Describe the B horizon. | It contains less humus so it is lighter in color, water reacts with carbon dioxide in this layer to form carbonic acid that leeches minerals out of the soil by dissolving them and washing them away. |
Describe the C horizon. | Made of partially weathered rock and is the last layer of the soil profile above the bedrock. |
What determines the soil type in an area? | It is determined by the climate (weather) of an area and results in different colors, depths, textures and fertility. |
What is soil erosion? | It is the movement of soil to a new location by wind or water. |
Why do humans want to stop soil erosion? | It causes the removal of topsoil that is necessary for plants to grow. |
What are some causes of soil erosion? | Steepness of slope, lack of vegetation, high levels of rainfall in a short period of time, forest clearcutting and animal overgrazing |
What can humans do to prevent erosion? | Planting windbreaks, no till-farming, contour farming, terracing |
What are some forces that cause erosion? | Gravity, water, wind or glaciers |
What is deposition? | The process where sediment is dropped by an erosional force as it loses energy. |
What is mass movement? | The movement of material down a slope by gravity in one large mass. |
List some examples of mass movement. | Slumping, creeping, rock falls or slides and mudflows. |
How can steep slopes be made safer and protect against mass movement? | The planting of vegetation, installing drainage pipes to channel runoff, the construction of concrete walls or barriers of railroad ties. |
What is a glacier? | A large mass of ice and snow that slowly moves on land causing erosion. |
What are the 2 types of glaciers? | Continental and valley glaciers |
What is a Continental glacier? | A huge mass of ice and snow that covers a large area of land. |
What is a valley glacier? | large masses of ice and snow found in mountain ranges. |
What is plucking? | Erosion caused by a moving glacier that will pick up boulders, gravel and sand and carry them along. |
What does a glacier do to the surrounding rocks and soil? | It will scour and scrape the soil and bedrock producing grooves and striations or stripes cut into the rock showing the direction the glacier is moving. |
What is till? | The deposit of different sized sediment by a glacier when it retreats. |
What is a Moraine? | a ridge or pile of sediment left at the end of a glacier |
What is outwash? | sediment deposited in layers by the meltwater of a glacier with the biggest pieces closest to the edge of the glacier. |
What is an esker? | An outwash deposit left by a glacier as meltwater rivers within the glacier deposit sand and gravel in the channel of the river |
Where are continental glaciers found? | Near the poles in Antarctica and Greenland. |
How much of the Earth is covered by Continental glaciers? | 10% |
What is an Ice Age? | a period of global cold weather (widespread glaciation) that have occurred over the last 2 to 3 million years. |
Where are valley glaciers found? | In mountain ranges |
What is a cirque? | A bowl shaped basin created by a valley glacier in the sides of mountains |
What is an arete? | A long ridge that forms between 2 valley glaciers that erode a mountain side-by-side |
What are horns? | Peaks that form when more than one valley glacier erodes a mountain from several sides |
What shape is a valley formed by a glacier? | "U" shaped |
What is erosion? | The movement of weathered sediments from one place to another. |
What is deflation? | The process when wind removes small particles of loose sediment leaving the larger heavier material behind. |
What is abrasion? | The process when wind acts like a sandblaster blowing sand grains against rocks wearing them down. |
What is a windbreak? | A row of trees, shrubs or plants that are planted to slow down wind to reduce erosion. |
What is a dune? | A mound or pile of sandy sediment that is drifted or piled by the wind. |
What is runoff? | Rainwater that doesn't soak into the ground or evaporate. |
List the factors that affect runoff. | amount of rainfall and length of time it falls, steepness or slope of land, amount and type of plants (vegetation) |
Describe a river system. | a network or group of groundwater and streams that come together to form a system |
Describe a drainage basin. | an area of land from which a stream or river collects runoff |
What is the largest drainage basin in the United States? | Mississippi River drainage basin |
Describe a young river. | flows swiftly through a steep valley, may have rapids and waterfalls, forms "V" shaped valleys by eroding the bottom of the river faster than the sides, it will create an alluvial fan where it empties onto a open plain |
Describe a mature river. | flows smoothly through a valley, creates meanders and oxbow lakes, carves a flat, broad valley floor called a floodplain,erodes more on the sides of the river than the bottom |
What is a floodplain? | a broad flat valley floor that is carved out by a mature river, the area near a river where flood waters from the river may occupy |
Describe an old river. | flows smoothly through a floodplain it has carved, it will form a delta if it empties into the ocean or lake |
What is a delta? | a fan shaped area formed by sediment that is deposited as water empties into the ocean or a lake |
What is an alluvial fan? | A fan shaped deposit formed by sediments that are deposited as water empties from a mountain valley (Young River) onto a flat open plain |
What is groundwater? | water that soaks into the ground and collects in the pores or spaces within the underlying soil and rock. |
What does permeable mean? | soil or rock that has pores spaces where water can pass through (sandstone) |
What does impermeable mean? | soil or rock that does not allow water to pass through (Granite) |
What is an aquifer? | Underground layer of permeable rock that allows water to move freely |
What is the zone of saturation in an aquifer? | The area where all the pore spaces are filled with water |
What is the water table? | the upper surface or boundary of the zone of saturation |
What is the purpose of a well? | they are used to pump groundwater from an aquifer to the surface |
What is an Artesian Well? | A well that does not require a pump because the water is under pressure. |
What is a spring? | An area where water flows freely from an aquifer because it is so close to the surface. |
What is a geyser? | A hot spring that erupts periodically shooting water and steam from the ground into the air |
How is a cavern formed? | Carbonic Acid in the groundwater dissolves limestone rock, enlargeing cracks in the rocks forming openings or chambers |
What is a stalactite? | A calcium carbonate deposit that forms and hangs from a cave ceiling |
What is a stalagmite? | A calcium carbonate deposit that form on the floor or ground in a cave |
List some cave formations created by depositon of calcium carbonate. | Soda straws, cave pearls, cave popcorn, draperies, columns |
List some forces that exist on an ocean shoreline that will erode away the coastline. | Waves pound the shore, currents move sediment along shore, tides carry sediment out and bring new sediment in |
What are 2 types of shoreline formations? | Rocks and cliffs, beaches |
How does a beach form? | Tides and waves deposit sediment parallel to the shore |
What is a Barrier Island? | Fragile sand deposits that parallel the shoreline but are separated from the mainland. |