Chapter 10 Earth and Water Study Guide
To obtain water, a(n) 1)_ must tap into an aquifer. The difference between the original water-table level and the water level in the pumped well is called the 2)_. In order for the water supply of the wells to be replenished, water from precipitation and run-off must 3)_ the zone of saturation. A(n) 4)_ contains water that is under pressure, which may cause the well water to spurt into the air.
1) well 2) drawdown 3) recharge 4) artesian well
Water under pressure from a confined aquifer.
Artesian well
What is capillary water?
Capillary water is water that is drawn upward through capillary action above the water table and is held in the pore spaces of rocks and sediment because of surface tension. It is found in the zone of saturation and the zone of aeration.
How are dripstone columns formed?
Dripstone columns are formed when stalagmites and stalactites form together.
True or False: Confined aquifers cannot become polluted.
False
True or False: It is very difficult to cause drawdown in an aquifer, no matter how many wells are tapped into the aquifer.
False
True or False: Most chemical containments can be removed easily from the groundwater aquifers.
False
True or False: Subsidence is caused by flooding caves.
False
True or False: To produce water, a well must be drilled deep into aquicludes.
False
True or False: Wells which contain pressurized water are called ordinary wells.
False
True or False: The combination of water (H20) and carbon dioxide (CO2) produces 'hydrogen (H)'.
False; Carbonic acid (H2C03)
True or False: Groundwater is slightly acidic and 'evaporates' limestone.
False; dissolves
True or False: Only a small portion of precipitation becomes 'groundwater' and is returned to the oceans though streams and rivers.
False; runoff
True or False: The flow velocity of groundwater depends on the 'height' of the water table.
False; slope
What is gravitational water?
Gravitational water is water that trickles downward as a result of gravity in the zone of saturation and the zone of aeration.
Major source of freshwater for human use.
Groundwater
What do we call water containing high concentrations of calcium, magnesium, or iron?
Hard water
Heated water discharged from the ground.
Hot spring
Limestone regions with sinkholes and sinking streams.
Karst topography
_, mostly in the form of rain and snow, falls into the oceans and on the land.
Precipitation
Where does radon originate?
Radon originates in the radioactive decay of uranium in rocks and sediment.
What are two natural pollutants?
Salt and radon
What are four common sources of groundwater pollution?
Sewage, landfills, waste disposal sites, and agriculture
How can salt get into freshwater supplies?
The overpumping of wells can cause the underlying salt water to rise into the wells and contaminate the freshwater aquifer.
What is the depth of the water table on hilltops?
The water table can be tens to hundreds of meters or more beneath the surface.
What is the depth of the water table in stream valleys?
The water table can only be a few meters deep.
What is the depth of the water table in swampy areas?
The water table is at the surface.
What kind of limestone is found in dripstone formations?
Travertine limestone
True or False: 'Common sources' of groundwater pollution include sewage and harmful chemicals.
True
True or False: An important artesian aquifer in the United States is the Ogallala aquifer.
True
True or False: Groundwater recharge is faster during periods of heavy precipitation.
True
True or False: If the recharge areas of confined aquifers are polluted, then the aquifer becomes polluted, too.
True
True or False: If the water tables drop, shallow wells can go dry.
True
True or False: Most pollution plumes spread extremely slowly, and time is available for alternate water supplies to be found.
True
True or False: Overpumping of groundwater can form a cone of depression around a well.
True
True or False: The depth of the water table in stream valleys is 'close' to Earth's surface.
True
True or False: Water in an aquifer with high porosity and high permeability flows faster than in an aquifer with low porosity and low permeability.
True
How are stalactites formed?
Water drips from the ceiling and loses carbon dioxide but precipitates calcite. The water freezes and gets longer over time.
How are stalagmites formed?
Water from the cave ceiling drips to the floor of the cave and slowly builds mound-shaped dripstones.
A major role in the formation of limestone is the _ a. dissolution and precipitation of calcium carbonate b. reaction of carbon dioxide with calcium carbonate c. reaction of water with limestone d. flooding of sinkholes
a. dissolution and precipitation of calcium carbonate
Most groundwater flow takes place through _, which are permeable layers of material.
aquifers
Which of the following statements is NOT true about groundwater? a. Most groundwater contains some acid b. Groundwater is made up mostly of H2O ions, which is why it readily dissolves limestone c. Carbonic acid forms when groundwater percolates through decaying organic material d. Calcium carbonate precipitates out when groundwater evaporates
b. Groundwater is made up mostly of H2O ions, which is why it readily dissolves limestone
Carbon dioxide and water form _ a. precipitated calcium carbonate b. carbonic acid c. underground limestone deposits d. calcium bicarbonate
b. carbonic acid
In order for caves to form in limestone, there must be _ a. runoff from surface streams b. no zone of saturation c. groundwater percolating through the cracks and joints of limestone d. sinkholes present
c. groundwater percolating through the cracks and joints of limestone
Many _ are three-dimensional underground passages, shafts, and chambers that stretch for many kilometers.
caves
Most _ of significant size are formed in limestone by the dissolving activity of groundwater.
caves
Some caves are _, while others contain underground streams and lakes.
dry
Only a very small amount of all of Earth's liquid _ is contained in rivers, streams, and lakes.
freshwater
About 97 percent of the _ is contained in the oceans.
hydrosphere
Precipitation that falls on land enters the ground through the process of _ and becomes groundwater.
infiltration
Through the process of _, much of the precipitation that falls on land becomes groundwater.
infiltration
Limestone regions with sinkholes, sinks, and sinking streams are said to have _.
karst topography
Materials, such as sand, with large, connected pores have a high _.
permeability
The _ and glaciers hold between 70 and 80 percent of Earth's freshwater.
polar ice caps
Small openings in subsurface Earth materials are pores, and the percentage of pore space in a material is its _.
porosity
The percentage of pore space, or _, of well-sorted sand is about 30 percent.
porosity
A depression in the ground caused by the collapse of a cave or by the direct dissolution of bedrock by acidic rain or moist soil is a(n) _.
sinkhole
Localized natural discharges of groundwater at Earth's surface are called _.
springs
Calcium carbonate deposits that hang from the ceiling of a cave are called _.
stalactites
Dripstone formations are composed of _, which is a type of limestone.
travertine
The upper boundary of the zone of saturation is the _.
water table
Water evaporates from seawater and forms invisible _ and visible clouds
water vapor
The winds and _ move the atmospheric water all over Earth.
weather systems
The _ is an area below Earth's surface that is completely saturated with water.
zone of saturation