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