A. Guaranteed to be purple, because only purple grand pianos are allowed in New Orleans. B. The same elevation as a kayaker in the river during a flood. C. Higher in elevation than a kayaker on the river during a flood. D. Lower in elevation than a kayaker on the river when the river is carrying its average water flow. E. In his book on the Mississippi, John McPhee noted that if you could take a supertanker out of the river, keep it at the same elevation but get it past the levees, it would hover over the floor of the Superdome like a blimp. The kayaker is the same; the low parts of the city are below river level even at low-water, and some of the city is below sea level as well. Points Earned: 1/1 Correct Answer: E Your Response: E Large rivers have many interesting features, including: 7. The natural levees, formed when flood waters leaving the channel slow down and drop much of their load near the channel; beyond the natural levees is the flood plain, where much of the rest of the mud in a flood is deposited in a thin layer. A. The flood plain, the flat region left behind when the river cuts downward to make a valley and leave uplands. B. The natural levees, high regions left behind when compaction of mud occurs beneath the river. C. The natural levees, formed when water rushing back into the river channel after floods erodes troughs away from the river. D. The flood plain, that flat area above where any floods reach. E. Many processes contribute to the formation of flood plains, but deposition of mud to smooth the surface is the most important one. Flood plains often occur beyond natural levees. The initial
slowdown as floodwater spreads from a river channel into the trees deposits sediment to form natural levees. Points Earned: 1/1 Correct Answer: A Your Response: A Geologically speaking, the water table: 8. Never changes its elevation, because it is pinned by the creeks. A. Rises during droughts, and sinks during rainy times. B. Sits next to the Pepsi table in Kern Commons. C. Separates the water-filled region near the Earth’s surface from the deeper region with some air in the spaces. D. Separates the water-filled region below the Earth’s surface from the region closer to the surface in which some air exists in the spaces. E. The water table is the surface below which all the spaces are full of water, but above which there is generally some air in the spaces. During droughts, water drains away from the ground to the creeks, so air enters spaces previously occupied by water, and the water table drops in elevation. Creeks do change in elevation between rain and drought (floods happen…). Points Earned: 0/1 Correct Answer: E Your Response: D Limestone, the type of rock most likely to contain caves, is made up of: 9. Rocks erupted from volcanoes. A.
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