Deck 13: Wildfires

Question 1

Were there wildfires before humans? (Choose the best answer.)

A) Yes, but they were very small because they had natural causes.
B) Yes and they were caused by natural igniters like lightning strikes or asteroid impact.
C) No. Humans are the only cause of wildfires.
D) No. There weren't trees before humans and so there couldn't be wildfires.
E) Maybe, but there is no record to find out.

Answer 1

B

Question 2

Which of the following is NOT released during wildfire?

A) Heat
B) Water vapor
C) Oxygen
D) Carbon dioxide
E) Light

Answer 2

C

Question 3

Which of the following wildfire types is dominated by fires moving along treetops?

A) Ground fires
B) Surface fires
C) Crown fires
D) Tree fires
E) Swamp fires

Answer 3

C

Question 4

Which type of wildfire would you most likely see moving through dry grasses during a drought?

A) Ground fires
B) Surface fires
C) Crown fires
D) Tree fires
E) Fast fires

Question 5

Which of the following best describes what happens during the combustion phase of wildfires?

A) Fuel is heated and ready to be ignited.
B) Fuel is ignited, leading to flames and smoldering.
C) Fuel explodes causing the wildfires to extinguish.
D) Fire reaches a source of water where it reacts strongly.

Question 6

If you have a wildfire coming, but you don't see big flames, what are you probably looking at?

A) Flaming combustion
B) Smoldering combustion
C) Pyrolosis combustion
D) Cool combustion
E) Internal combustion

Question 7

What is the difference between preheating and pyrolysis?

A) Preheating is caused by added heat, pyrolysis is caused by added chemicals.
B) Preheating is a natural process, pyrolysis is man-made.
C) Preheating involves drying of the fuel, pyrolosis involves a chemical change in the fuel.
D) Only preheating is necessary for a wildfire.
E) Preheating changes the fuel, pyrolosis changes the products in a fire.

Question 8

Which of the following is NOT a factor in how mountains increase wildfire incidence or intensity?

A) Air dries as it descends down mountains.
B) Mountains circulate winds causing fires to move more quickly.
C) Fires moving upslope preheat materials ahead of fire making them easier to burn.
D) Drier materials are found on slopes that face sunlight during the day.
E) Mountains have higher oxygen contents that promote rapid wildfire development.

Question 9

Which of the following statements is FALSE about wildfires?

A) Before humans evolved, fires that were ignited by lightning or volcanic eruptions would burn until they ran out of fuel or were extinguished naturally.
B) Wildfires date back more than 350 million years when trees evolved and spread across the globe.
C) Some species of trees have seed cones that open only after a fire.
D) Early European settlers of North America brought the ability to use fire for heat, light, and cooking to Native Americans.
E) Wildfires became more frequent and grew quicker about 20 million years ago when grasses evolved.

Question 10

Which of the following is NOT one of the main phases of wildfire?

A) Preignition
B) Extinction
C) Conductive radiation
D) Combustion

Question 11

Which of the following best describes what happens during the preignition process in wildfire development?

A) Fuel is heated, it loses water and is ready to be ignited.
B) Fuel at the front of a fire is ignited.
C) Fuel gains carbon dioxide and is ready to burn.
D) Gases heat and expand into fuel.
E) Gases cool and contract to produce fuel.

Question 12

Which of the following is NOT required for a fire to burn?

A) Heat
B) Fuel
C) Oxygen
D) Carbon dioxide

Question 13

Which of the following is NOT an important indicator of whether a region is prone to wildfires?

A) Humidity
B) Topography
C) Vegetation type
D) Temperature
E) Bedrock composition

Question 14

Which of the following describes convection, which is one kind of heat transfer process during the combustion phase of wildfire?

A) Transmission of heat through molecular contact
B) Heat transfer though electromagnetic waves
C) Heat transfer by the movement of heated gases driven by temperature differences in air
D) Heat transfer by endothermic chemical reactions
E) Heat transfer by splitting large fuel molecules into smaller ones

Question 15

What is the role of convection in wildfires?

A) Rising hot air in the fire pulls in fresh air to fuel the flames.
B) Rising hot air in the fire pulls in fresh air to extinguish the flames.
C) Sinking hot air in the fire pushes air out the fire to extinguish the flames.
D) Sinking hot air in the fire pushes air out of the fire to fuel the flames.
E) Rising and falling air within the fire causes the fire to reuse air as fuel.

Question 16

Which of the following describes conduction, which is one kind of heat transfer process during the combustion phase of wildfire?

A) Transmission of heat through molecular contact
B) Heat transfer though electromagnetic waves
C) Heat transfer by the movement of heated gases driven by temperature differences in air
D) Heat transfer by endothermic chemical reactions
E) Heat transfer by splitting large fuel molecules into smaller ones

Question 17

Which of the following statements about wildfire combustion is TRUE?

A) Wildfires ignite repeatedly in order to keep moving.
B) All lightning strikes, if they have enough energy, will cause a wildfire to ignite.
C) Human activity is the only thing that can ignite a wildfire.
D) Combustion involves the absorption of energy in a fire.

Question 18

Which of the following describes radiation, which is one kind of heat transfer process during the combustion phase of wildfire?

A) Transmission of heat through molecular contact
B) Heat transfer though electromagnetic waves
C) Heat transfer by the movement of heated gases driven by temperature differences in air
D) Heat transfer by endothermic chemical reactions
E) Heat transfer by splitting large fuel molecules into smaller ones

Question 19

Which type of wildfire would you most likely see moving through a dry swamp during a drought?

A) Ground fires
B) Surface fires
C) Crown fires
D) Tree fires
E) Drought fires

Question 20

What is the role of radiation in keeping a wildfire burning?

A) Radiation from flames decreases the heat of the fire, leading to extinction.
B) Radiation from the Sun adds heat to the fire, causing it to burn more quickly.
C) Radiation from flames pre-heats fuel ahead of the fire, causing the fire to move forward.
D) Radiation from the Earth heats fire, causing it to burn more quickly.
E) Radiation from flames causes disease in trees and wildlife near the fire zone.

Question 21

Which of the following is a good reason for a prescribed burn?

A) Too much fuel is available and needs to be removed to prevent a larger fire.
B) Animals that are invading a habitat need to be moved to another location.
C) Shrubland needs to be cleared for new housing.
D) Vegetation on hillsides needs to be cleared before the rainy season.
E) The ground needs to be fused to prevent erosion.

Question 22

Wildfires are a phenomenon caused only by human interaction.

Question 23

The presence of mountains has a very strong influence on wildfire activity in an area.

Question 24

Fires will occur whether or not people start them, and humans play a relatively minor role in affecting large wildfires.

Question 25

Convection in a wildfire adds more fresh air to fuel the flames.

Question 26

The Great Chicago Fire of 1871 is the deadliest fire in U.S. history.

Question 27

In which of the following regions are wildfires LEAST likely to begin?

A) Grasslands
B) Woodlands
C) Marshes
D) Rainforests
E) Sand dunes with no vegetation

Question 28

Before a wildfire actually starts to burn, the fuel needs to be at a favorable temperature and humidity.

Question 29

Large wildfires that occur regularly in a location every 50 to 100 years will not become established unless sufficient fuel is present.

Question 30

Why do wildfires increase landslide activity?

A) Burning the anchoring vegetation leaves the ground exposed.
B) Burning the soil makes it heavier, making landslides more likely.
C) Wildfires move downhill, pulling soil and trees with it.
D) Wildfires dry the soil, which reduces its shear strength and makes it likely to slide.

Question 31

Which of the following is NOT an example of how wildfires are beneficial to the environment?

A) May trigger a release of seeds for some species
B) Remove surface debris for grasses
C) Recycle nutrients in the ecosystem
D) Increase the amount of plants that can grow
E) Fires create deeper river channels that reduce flooding hazards.

Question 32

Which of the following locations in the U.S. has the lowest risk of wildfires?

A) California
B) Nevada
C) New Mexico
D) Maine
E) Alaska

Question 33

Weather, especially temperature, precipitation, relative humidity, and wind, has a dominant influence on wildfire.

Question 34

Ignition by a lightning strike will always lead to a wildfire.

Question 35

Some of the heat in a fire is transferred by radiation.

Question 36

Only people can prevent wildfires.

Question 37

People on hillsides are usually safe from wildfires because the fires cannot climb hills.

Question 38

Which of the following is NOT an example of why warming of the climate would increase the wildfire hazard?

A) Temperature increases and humidity decreases will leave fuel dry and warm.
B) Grasslands replacing forests will provide more fuel.
C) Increased storm activity will increase the number of lightning strikes, increases ignitions.
D) Increased insect activity will leave trees and other vegetation more vulnerable to burning.
E) Increased volcanic eruptions will trigger more wildfires.

Question 39

Which of the following is NOT an effect of wildfires?

A) Increased landslide activity
B) Increased earthquake activity
C) Increased smog
D) Decreased water quality
E) Destroyed animal habitats

Question 40

Flaming combustion usually involves higher temperatures than smoldering combustion.

Question 41

In some areas, park rangers or other officials may intentionally set fires in order to manage the forests.

Question 42

Most animals are able to escape from the actual flames of a wildfire, but are harmed by destruction to their habitats.

Question 43

Because wildfires occur above ground, they have little impact on soil.

Question 44

Little can be done in the area of public education about wildfire due to the technical nature of that information.

Question 45

Requiring fire insurance is the single best strategy to reduce damage from wildfire.

Question 46

Florida is the only U.S. state that has never experienced wildfire.

Question 47

What are the three requirements for fire to start and for combustion to continue? What happens when one of these requirements is removed?

Question 48

Even large crown fires are relatively easy to extinguish because those fires only burn the very uppermost parts of trees.

Question 49

In southern California it is common for an area to experience flooding and debris flows after major wildfires have occurred.

Question 50

Wildfires are mostly caused by people and can be prevented through more education.

Question 51

In the long run, wildfires are actually beneficial to the ecosystems in which they occur.

Question 52

Prescribed burns to reduce the fuel load have been extremely successful in stopping large wildfires in southern California.

Question 53

Global warming is expected to increase both the frequency and intensity of wildfires.

Question 54

State-wide zoning laws in California prevent residential development in areas at risk for wildfire.

Question 55

Burning of plant material recycles nutrients in the system by quickly decomposing organic matter and allowing new plants to grow.

Question 56

For the past century, wildfire suppression in the U.S. has been remarkably successful in suppressing damage from wildfire.

Question 57

Wildfires decrease the possibility of landslides because they burn off most of the vegetation on the hillsides.

Question 58

Large wildfires create their own clouds and release smoke, soot, and invisible gases that contribute to air pollution.

Question 59

Alaska and the Pacific Northwest have a low incidence of wildfires because it is too wet and too cold there.

Question 60

Explain what happens to fuel during the preignition phase.

Question 61

Describe the three wildfire phases and give examples of each.

Question 62

Describe the three wildfire types and describe environments that would facilitate their growth.

Question 63

Describe the three processes control the transfer of heat as wildfire moves across the landscape.

Question 64

Explain why global warming would increase wildfire activity.

Question 65

Describe some of the positive effects of wildfires.

Question 66

Which North American regions are most vulnerable to wildfire? Why does the risk shift from year to year?

Question 67

It is possible to have wildfires in the rainforest. How is this possible? Under what conditions will wildfires occur?

Question 68

How does topography influence a wildfire?

Question 69

Describe the events surrounding the Yellowstone fires of 1988. Based on your understanding of wildfires, do you think that the Yellowstone Natural Burn Policy is an appropriate policy or not? Describe the pros and cons of a natural burn and explain why you chose the side that you did.

Question 70

Wildfires are frequent in some areas of Southern California. Explain why wildfires are frequent here. What conditions will cause wildfire activity. Explain what Californians could do to decrease the effects of the fires.