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40 terms

GEO CH 16

STUDY
PLAY
Sinkholes are a concern primarily for residents whose dwellings are constructed atop __.; a. sandstone; b. shale; c. limestone; d. granite;
c
The majority of Earth's liquid freshwater exists in __.; a. lakes; b. rivers and streams; c. pores within rock and sediment; d. atmospheric clouds; ;
c
Unconsolidated sediment typically has greater porosity than the lithified rock that forms from it.; a. true; b. false; ;
a
Primary porosity may be reduced by the __.; a. compaction of grains; b. cementation of grains; c. Both A and B are correct.; d. None of the above is correct.;
c
Groundwater __.; a. does not affect the porosity of the rock and sediment through which it flows; b. uniformly increases porosity due to dissolution of grains; c. uniformly decreases porosity due to deposition of minerals into pores; d. may increase or decrease porosity through dissolution or deposition; ;
d
As a rule, groundwater always flows from areas __.; a. of greater elevation to those of lesser elevation; b. of greater permeability to those of lesser permeability; c. of greater hydraulic head to those of lesser hydraulic head; d. near streams to areas beneath mountain ranges; ;
c
Material through which water readily flows is termed __.; a. fluent; b. porous; c. permeable; ;
c
If a material is porous, it __.; a. will be permeable as well; b. will be impermeable; c. may be permeable or impermeable; ;
c
If a material is highly permeable, it __.; a. must be porous; b. cannot be porous; c. must be fractured; d. must either have substantial porosity or be fractured; ;
d
. In unfractured rock and sediment, water molecules usually take a __.; a. straight path; b. wandering path; c. circular path; ;
b
A layer of rock or sediment with exceptionally low permeability is termed a(n) __ in hydrogeologic contexts.; a. aquitard; b. confined aquifer; c. unconfined aquifer; d. unsaturated zone; ;
a
Rock or sediment with water-filled pores, wherein upward percolation is blocked by an overlying, impermeable layer, is termed a(n) __.; a. aquitard; b. confined aquifer; c. unconfined aquifer; d. unsaturated zone; ;
b
Permeable rock or sediment between the water table and the land surface represents a(n) __.; a. aquitard; b. confined aquifer; c. unconfined aquifer; d. unsaturated zone; ;
d
A body of permeable rock or sediment that possesses a water table is termed a(n) __.; a. aquitard; b. confined aquifer; c. unconfined aquifer; d. unsaturated zone; ;
c
In a humid climate, the topography of the water table __.; a. is unaffected by local surface topography; b. precisely mimics the topography of the ground surface; c. is a subdued (less steeply sloping) mimic of surface topography; d. is an exaggerated (more steeply sloping) mimic of surface topography; ;
c
Unless it has recently rained, there is no water within pores in the unsaturated zone.; a. true; b. false; ;
b
Perched water tables occur __.; a. above the regional water table, within permeable rock or sediment; b. above the regional water table, within impermeable rock or sediment; c. below the regional water table, within impermeable rock or sediment; d. below the regional water table, within permeable rock or sediment; ;
a
Which statement about recharge areas is INCORRECT?; a. They typically are elevated with respect to neighboring areas.; b. They are regions of relatively high precipitation.; c. They are the same as discharge areas.; d. They are areas where water infiltrates the sediment from above.; ;
c
Freshwater lakes are always discharge areas.; a. true; b. false; ;
b
The rate of groundwater flow through a body of rock or sediment depends __.; a. only on the slope of the water table locally; b. only on the porosity of the rock or sediment; c. on the slope of the water table and the porosity of the rock or sediment; d. on the slope of the water table and the permeability of the rock or sediment;
d
The relationship governing the rate of groundwater flow was discovered by __.; a. Alfred Wegener; b. Isaac Newton; c. Henry Darcy; d. Charles Richter; ;
c
. In groundwater, __.; a. dissolved ions are rarely, if ever, found; b. calcite (in limestone) is more soluble than quartz (in sandstone); c. minerals may be dissolved but will never precipitate out of solution; d. precipitation may take place but only if the mineral in question is undersaturated; ;
b
23. Hard water results from relatively high concentrations of dissolved __.; a. calcium and magnesium; b. francium and cesium; c. sodium; d. potassium; ;
a
An ordinary (water-producing) well will result whenever the base of the well extends below the water table.; a. true; b. false; ;
a
The elevation of the water table __.; a. is a constant for a given area so long as the topography remains the same; b. may rise during times of drought and sink during rainy periods; c. may rise during rainy periods and sink during droughts; ;
c
A dry well will result whenever the base of the well is above the water table.; a. true; b. false; ;
a
Pumping vast quantities of water locally __.; a. raises the local water table; b. lowers the local water table, forming a cone-shaped depression; c. lowers the local water table, forming a cylindrical depression; d. does not affect the water table; ;
b
The majority of large cave and karst systems have resulted from __ etching into __.; a. carbonic acid; limestone; b. ascorbic acid; dolostone; c. phosphoric acid; shale; d. sea water; rock salt; ;
a
Any place where groundwater naturally flows outward at the surface of Earth is termed a __.; a. flowing artesian well; b. geyser; c. spring; d. recharge area; ;
c
Water flowing from hot springs __.; a. contains more dissolved minerals than water flowing from cool springs; b. contains fewer dissolved minerals than water flowing from cool springs; c. is never hotter than 40°C, so it is always safe to bathe in; d. only occurs in regions of active volcanism; ;
a
A periodic explosive eruption of steam and water from within the ground up through; the surface is termed a __.; a. flowing artesian well; b. geyser; c. spring; d. recharge area; ;
b
. Land subsidence is likely whenever __.; a. groundwater is used nonrenewably from aquifers composed of rock; b. groundwater is used nonrenewably from aquifers composed of sediment; c. groundwater is used renewably from aquifers composed of rock; d. groundwater is used renewably from aquifers composed of sediment; ;
b
If groundwater is clear, it can be assumed that it is drinkable.; a. true; b. false; ;
b
Most dissolution of bedrock to form caves takes place __.; a. above the water table; b. just below the water table; c. greater than 10 m below the water table; ;
b
. An artesian well is one that __.; a. induces an upward flow of groundwater without any pumping; b. has its intake sited within the saturated zone of an unconfined aquifer; c. has its intake sited within the unsaturated zone of an unconfined aquifer; d. has its recharge area at an elevation below sea level; ;
a
Topography dominated by depressions formed by the collapse of caves is termed __.; a. valley and ridge; b. karst; c. horst and graben; ;
b
Well-sorted sediments typically have __ porosity compared to poorly sorted sediments.; a. greater; b. less; c. approximately the same; ;
a
Extensive pumping of fresh groundwater from a coastal aquifer can induce __.; a. saline intrusion; with time the well will start to deliver saline water; b. saline expulsion; with time the freshwater/saline water interface within the aquifer will be pushed downward and seaward; ;
a
Dissolution of grains in the burial environment produces __.; a. primary porosity; b. primary permeability; c. secondary porosity; d. a reduction in primary porosity; ;
c
Bioremediation of contaminated groundwater involves __.; a. introducing laboratory-cultured viruses that can dissolve the plume; b. pumping oxygen and nutrients into a contaminant plume to help local bacteria metabolize the plume; c. pumping out the contaminated groundwater and using it to irrigate genetically modified crops; ;
b