Ch. 9 and 17 Geology

In which state would you NOT expect to find karst?

California

How can a homeowner create a defensible space in order to obtain fire insurance?

Clear ground duff and brush and cut down trees on all sides of the house.

A burned tree with white residue on the west side and black residue on the east side indicates the fire came from the east.

False

A fire progresses more quickly downslope than upslope

False

Erosion is less likely in forest areas after a fire because of the build-up of burned organic material.

False

Rainwater becomes acidic as it dissolves limestone.

False

Which precaution is NOT suggested during evacuation due to a fire?

Open all interior doors in your house.

​_______________ is soil containing frozen groundwater.

Permafrost

_______________ clay is most involved with swelling soils.

Smectite

A narrow firebreak is usually enough to provide a defensible fireline.

True

Sinkholes are formed as a result of the collapse of a limestone cavern.

True

Landslides due to the melting of permafrost ____.

create rotational slumps as deeper thawed areas loosen the connection of permafrost to the supporting layers

Which is NOT a potentially harmful air pollutant created by wildfires?

dihydrogen oxide

Burning embers are also called _______________.

firebrands

​Land subsidence increases the hazard of ____.

flooding

Exposure of limestone rock creates an uneven and potholed surface called _______________.

karst

Low brush and branches are known as _______________ fuels because they ignite first and then allow the fire to climb into higher treetops.

ladder

What condition does NOT contribute to more fire-prone forests?

larger trees

The most dangerous part of the day for firefighting is _____, when weather is hottest and winds often blow the fire in unpredictable directions.

late afternoon

The three components of the fire triangle are fuel, heat, and _______________.

oxygen

Sunlight can react with pollutants generated by a wildfire to form _______________.

ozone

Deliberate deforestation by fire has occurred in Indonesia, where forests are burned to clear space for growing _______________.

palm oil, commercial crops

The effects of land subsidence due to groundwater extraction are generally ____.

permanent and irreversible

A controlled fire set intentionally is called a(n) _______________.

prescribed burn

Why do grass, needles, and shrubs burn easier and faster than trees?

They have a large surface area compared with their total mass

Swelling soils are typically due to ____.

smectite clay increasing in volume as it absorbs water

In addition to limestone, evaporites like ____ and ____ can create underground cavities.

smectite; salt

With climate change, more frequent and larger wildfires emit greater amounts of carbon into the atmosphere.

True

​In order to dissolve limestone, groundwater must be slightly _______________.

acidic

What creates caverns in limestone rock?

acidic rainwater dissolves limestone rock, leaving empty caverns

A sinkhole is most likely to form ____.

at the end of a dry season

The damage due to swelling soils results in losses of ____ in the United States.

billions of dollars, primarily through damage to highways and streets,

Limestone consists of rock made from ____.

calcium carbonate

Land subsidence that results from petroleum mining ____.

can be mitigated by pumping fluid into the well

Clays play a role in land subsidence by ____.

collapsing into compact layers when dried, increasing subsidence

Water and soil percolating through karst fissures can create a small depression through the process of _______________.

dissolution

Wildfires benefit forests in many ways. Which is NOT one of these?

improving landscape views for inhabitants

Thawing permafrost _______________.

increases climate change dangers by injecting warm water into the Arctic Ocean

What public policy change followed the tragic Melbourne, Australia fire of 2009?

instituting a nationwide fire alert system involving telephone and text messaging

Which source of information is NOT typically used by fire investigators in determining a fire's cause?

records of past fires in the area

Which measure is NOT used to minimize erosion following a fire?

removing dead trees

Highly trained firefighters who parachute into remote areas of lightning-caused spot fires to exterminate them before they spread out of control are called _______________.

smokejumpers

A(n) _______________ hangs from the ceiling of a cavern.

stalactite

Fires that spread along the ground fueled by grasses and low shrubs are called _______________.

surface fires

What is NOT a primary consideration in establishing fire risk for an area?

the amount of available firefighting resources

Which area of the U.S. generally has the highest (worst) fire weather potential?

the desert southwest

In California, between 2001 and 2009, what was the largest cause of wildfires?

unsafe use of power equipment

A convective _______________ of heat draws in new air from all sides and fans flames.

updraft

What distance of space cleared of any fuels around a house is recommended?

30 m

The uneven, potholed surface of karst is caused by ____.

erosion from ancient streambeds

The amount of burnable material available to a fire is called _______________.

fuel loading

The level to which _______________ rises in a well is the location of the water table.

groundwater

The decomposition of peat layers in soils ____.

happens during abnormally dry seasons

Which factor does NOT contribute to the intensity of a wildfire?

the initial cause of the fire

In order for limestone to collapse to form a major sinkhole, the ground above must be ____.

thick and rich in cohesive clay to allow a cavern to form