* Construction of a heavy building above a cavity loads it and can cause collapse. What material causes swelling soils? * smectite, the swelling clay What parts of United States and Canada are most susceptible to damage from swelling soils? * The Great Plains, east of the Rockies, the Gulf Coast states of Texas, Louisiana, and Mississippi, the Coast Ranges of California, some valleys of the Rocky Mountain states. How can you recognize the presence of swelling soils? * They are extremely slippery when wet. * The form a popcorn-like surface when dried out. What is bad about swelling soils? * Swelling deforms and cracks foundations, chimneys, walls, driveways, and roads. * Roads are extremely slippery when wet. * Landslides are more common. A cavity in what kind of material suddenly collapses to form a sinkhole? * sandy to clay-rich soil What is in water in the ground that helps it dissolve limestone? Where does that substance come from? * carbonic acid. It forms from carbon dioxide in air combining with rainwater. Name three of the eight states with the largest areas of ground subsidence, including sinkholes. * Florida, Georgia, Texas, New Mexico, Kentucky, Tennessee, Virginia, Missouri What are two main mechanisms of ground subsidence? * sinkholes, extraction of water or other fluids from sediments, and drainage of peat or other organic soils. How would you recognize a karst landscape? * a ragged limestone surface. “dissolved” Venice, Italy, is noted for numerous canals instead of normal streets that cars drive on. Why doesn’t it have many normal streets? Explain briefly and to the point. * extraction of groundwater under the city caused subsidence and sinking of the city below sea level. What specific area of the western United States is noted for almost 8 meters of subsidence in the past 100 years? Specifically what caused the subsidence? * The San Joaquin Valley (Great Valley of California). Subsidence caused by extraction of groundwater for agriculture.
* Construction of a heavy building above a cavity loads it and can cause collapse. What material causes swelling soils? * smectite, the swelling clay What parts of United States and Canada are most susceptible to damage from swelling soils? * The Great Plains, east of the Rockies, the Gulf Coast states of Texas, Louisiana, and Mississippi, the Coast Ranges of California, some valleys of the Rocky Mountain states. How can you recognize the presence of swelling soils? * They are extremely slippery when wet. * The form a popcorn-like surface when dried out. What is bad about swelling soils? * Swelling deforms and cracks foundations, chimneys, walls, driveways, and roads. * Roads are extremely slippery when wet. * Landslides are more common. A cavity in what kind of material suddenly collapses to form a sinkhole? * sandy to clay-rich soil What is in water in the ground that helps it dissolve limestone? Where does that substance come from? * carbonic acid. It forms from carbon dioxide in air combining with rainwater. Name three of the eight states with the largest areas of ground subsidence, including sinkholes. * Florida, Georgia, Texas, New Mexico, Kentucky, Tennessee, Virginia, Missouri What are two main mechanisms of ground subsidence? * sinkholes, extraction of water or other fluids from sediments, and drainage of peat or other organic soils. How would you recognize a karst landscape? * a ragged “dissolved” limestone surface. Venice, Italy, is noted for numerous canals instead of normal streets that cars drive on. Why doesn’t it have many normal streets? Explain briefly and to the point. * extraction of groundwater under the city caused subsidence and sinking of the city below sea level. What specific area of the western United States is noted for almost 8 meters of subsidence in the past 100 years? Specifically what caused the subsidence? * The San Joaquin Valley (Great Valley of California). Subsidence caused by extraction of groundwater for agriculture.
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