Geology (50-year Flood) 28 Answer Key

Question 1 1 / 1 pts Which of the following statements regarding floods is true? Correct! A 50-year flood has a 2% chance of occurring in any one year. A 50-year flood is generally larger than a 100-year flood. A 50-year flood occurs more frequently than a 5-year flood. A 50-year flood on one river is the same size as a 50-year flood on another river. Question 2 1 / 1 pts In geology, the term stream is applied to any body of water flowing over the surface, regardless of the size of that body of water. Correct! True False Question 3 1 / 1 pts What is the probability of a 50-year flood occurring next year along the Skykomish River in Washington State? 1% Correct! 2% 10% 50% Question 4 1 / 1 pts Which of the following would be the most fertile area for crops? a stream channel Correct! a floodplain a natural levee an uplands area away from the stream Question 5 1 / 1 pts In the map of a stream, the arrow is pointing to a(n) ____________. natural levee Correct! oxbow lake point bar sand dune Question 6 1 / 1 pts Oxbow lakes are associated with which of the following types of rivers? braided rivers dendritic rivers Correct! meandering rivers straight rivers Question 7 1 / 1 pts The velocity of a river multiplied by the cross-sectional area of the river channel yields the river's capacity Correct! discharge recurrence interval none of these Question 8 1 / 1 pts Which of the following types of streams has many channels? Correct! braided streams meandering streams both braided and meandering streams neither braided nor meandering streams Question 9 1 / 1 pts Curves and bends in a stream channel are called ______. alluvial fans braids deltas Correct! meanders Question 10 1 / 1 pts For a given river, which of the following floods would have the largest discharge? a 5-year flood a 20-year flood Correct! a 50-year flood One cannot tell from the information provided Question 11 1 / 1 pts The word _____ is used for any flowing body of water large or small. river Correct! stream channel drainage Question 12 1 / 1 pts Which of the following forces is the dominant cause of mass movement? Correct! gravity seismic energy tidal force wind Question 13 1 / 1 pts The volume of water flowing past a given point in a given time is called the ______. capacity competence Correct! discharge viscosity Question 14 1 / 1 pts For most rivers, discharge __________ downstream. Correct! increases remains constant decreases slightly decreases greatly Question 15 0 / 1 pts A ridge of high land between two streams is called a Correct Answer divide You Answered drainage network natural levee none of these Question 16 1 / 1 pts In which of the following locations would one most likely find a braided stream? Correct! at the edge of a melting glacier on a gently sloping plain of fine-grained sediment in a narrow gorge cut into bedrock all of the above Question 17 1 / 1 pts Where does a stream channel begin? where rainwater infiltrates into the subsurface weakening the underlying bedrock where there are active faults that create cracks in the underlying bedrock Correct! where rainwater flows over the surface so fast that it carves into the underlying units where there are pre-existing weaknesses in the bedding planes in the underlying units Question 1 1 / 1 pts After oceans, which of the following reservoirs contains the most water? Correct! the glaciers and polar ice caps the lakes and rivers the underground waters the atmosphere Question 2 1 / 1 pts The process by which surface water becomes groundwater is called transpiration. discharge. evaporation. Correct! infiltration. Question 3 1 / 1 pts What powers the hydrologic cycle? Correct! solar energy mantle convection magnetism radioactive decay Question 4 1 / 1 pts The largest freshwater reservoir in the hydrologic cycle is groundwater. the biosphere. Correct! glaciers. the atmosphere. Question 5 1 / 1 pts The release of water vapor from plants is called infiltration. Correct! transpiration. evaporation. precipitation. Question 6 1 / 1 pts Groundwater represents how much of the world's fresh water? approximately 35% approximately 1% Correct! approximately 29% approximately 12% Question 7 1 / 1 pts Layers that transmit groundwater are called Correct! aquifers. influent streams. aquicludes. unsaturated zones. Question 8 1 / 1 pts Which of the following unfractured rocks has the highest porosity? granite shale Correct! sandstone schist Question 9 1 / 1 pts Which of the following statements regarding porosity and permeability is true? Correct! High porosity rocks generally have high permeability. High porosity rocks generally have low permeability. Porosity and permeability have identical meanings. Low porosity rocks generally have high permeability. Question 10 0 / 1 pts Which of the following sandstones will have the highest porosity? a well-sorted, cemented sandstone Correct Answer a well-sorted, uncemented sandstone You Answered a poorly sorted, uncemented sandstone a poorly sorted, cemented sandstone Question 11 1 / 1 pts Permeability is the Correct! ability of a solid to allow fluids to pass through. percentage of pore space in a rock. amount of water vapor in the air relative to the maximum amount of water vapor the air can hold. process by which plants release water vapor to the atmosphere. Question 12 1 / 1 pts In the unsaturated zone, pore spaces in the soil and rock contain air. Correct! air and water. water. neither air nor water. Question 13 0 / 1 pts Which of the following combinations make for the best groundwater reservoir? low permeability and low porosity low permeability and high porosity You Answered high permeability and low porosity Correct Answer high permeability and high porosity Question 14 1 / 1 pts What is the difference between the saturated and unsaturated zones of groundwater? The saturated zone has a lower porosity than the unsaturated zone. The pore spaces in the saturated zone are not full of water; the pore spaces in the unsaturated zone are full of water. The saturated zone has a higher porosity than the unsaturated zone. Correct! The pore spaces in the saturated zone are full of water; the pore spaces in the unsaturated zone are not full of water. Question 15 1 / 1 pts Which of the following statements about the groundwater table is true? Correct! The groundwater table has the same general shape as the topography. The groundwater table changes when discharge is balanced by recharge. The groundwater table is well below the land surface beneath lakes. The groundwater table is elevated near high-volume pumping wells. Question 16 1 / 1 pts Which of the following statements is true? Influent streams recharge groundwater and are characteristic of humid regions. Influent streams discharge groundwater and are characteristic of arid regions. Correct! Influent streams recharge groundwater and are characteristic of arid regions. Influent streams discharge groundwater and are characteristic of humid regions. Question 17 1 / 1 pts Which of the following represents the boundary between the saturated zone and the unsaturated zone? aquiclude porosity aquifer Correct! groundwater table Question 18 1 / 1 pts Which of the following statements regarding effluent streams is true? Effluent streams recharge groundwater and are characteristic of humid regions. Effluent streams recharge groundwater and are characteristic of arid regions. Correct! Effluent streams are fed by groundwater and are characteristic of humid regions. Effluent streams are fed by groundwater and are characteristic of arid regions. Question 19 1 / 1 pts What type of aquifer is bounded above and below by relatively impermeable beds? saturated Correct! confined unconfined aquiclude Question 20 1 / 1 pts If the amount of discharge in an aquifer exceeds the amount of recharge, the groundwater table may rise or drop depending on the permeability. Correct! will drop. will remain the same. will rise. Question 21 1 / 1 pts Which of the following is not caused by overpumping groundwater? development of cracks and fissures at the surface intrusion of salt water into coastal aquifers Correct! raising of the land surface depletion of an aquifer Question 22 1 / 1 pts Which of the following statements about groundwater in coastal regions is true? Fresh water is denser than seawater; therefore, salty groundwater floats on top of fresh groundwater. Correct! Seawater is denser than fresh water; therefore, fresh groundwater floats on top of salty groundwater. Seawater is denser than fresh water; therefore, salty groundwater floats on top of fresh groundwater. Fresh water is denser than seawater; therefore, fresh groundwater floats on top of salty groundwater. Question 23 1 / 1 pts How fast does most groundwater move in aquifers? Correct! a few centimeters per day a few tens of kilometers per day a few kilometers per day a few meters per day Question 24 1 / 1 pts In what type of rock do most caves form? granite Correct! limestone shale sandstone Question 25 1 / 1 pts Sinkholes are a possible danger in regions underlain by what type of bedrock? shale Correct! limestone sandstone granite Question 26 1 / 1 pts ________ is the infiltration of water into the saturated zone, and _______ is the exit of groundwater to the surface. Hydration; outflux Permeation; evaporation Seepage; outflow Correct! Recharge; discharge Question 27 1 / 1 pts The main difference between a hot spring and a geyser lies in the chemistry of the water. bedrock the water flows through. Correct! regularity of the underground plumbing system. temperature of the water. Question 28 1 / 1 pts Geysers have ____________ than regular hot springs. colder water hotter water Correct! more irregular plumbing systems a higher recharge rate