S-190 Intro to Wildland Fire Behavior
Point of origin - ANSWERSThe precise location where a competent ignition source came into contact with the
material first ignited and sustained combustion occurred.
Head of a fire - ANSWERSThe side of the fire having the fastest rate of spread
Flank of a fire - ANSWERSThe part of a fire's perimeter that is roughly parallel to the main direction of spread.
Rear of a fire - ANSWERSPortion of a fire spreading directly into the wind or down slope. Opposite the head.
Slowest spreading portion of a fire edge. Also called the heel
3 main objectives to fight a fire - ANSWERSAnchor, Flank, Pinch
Fire perimeter - ANSWERSEntire outer edge of a fire
Fingers of a fire - ANSWERSLong narrow extensions of a fire projecting from the main body
Pockets of a fire - ANSWERSUnburned indentations in the fire edge formed by fingers or slow burning areas
Island - ANSWERSArea of unburned fuel inside the fire perimeter
Spot fire - ANSWERSFire ignited outside the perimeter of the main fire by a fireband
Smoldering - ANSWERSFire burning without flame and barely spreading
Creeping fire - ANSWERSFire burning with a low flame and spreading slowly
Running fire - ANSWERSBehavior of a fire spreading rapidly with a well defined head
,Spotting - ANSWERSBehavior of a fire producing sparks or embers that are carried by the wind and which start
new fires beyond the zone of direct ignition by the main fire
Torching - ANSWERSThe burning of foliage of a single tree or a small group of trees from the bottom up
Crown fire - ANSWERSFire that advances from top to top of trees or shrubs more or less independent of
surface fire. Sometimes classes as running or dependent to distinguish the degree of independence from the
surface fire.
Flare up - ANSWERSAny sudden acceleration in the rate of spread or intensification. Relatively short-duration.
Junipers cause a lot of these.
Firewhirl - ANSWERSSpinning vortex column of ascending hot air and gases rising from a fire and carrying aloft
smoke, debris, and flame. Can move all over and are unpredictable.
Backing fire - ANSWERSThat portion of the fire with slower rates of spread. Also called the heel
Flaming front - ANSWERSThat zone of a moving fire where the combustion is primarily flaming. Light fuels
typically have a shallow flaming front. Heavy fuels have a deeper front.
Anchor point - ANSWERSAn advantageous location, usually a barrier to fire spread, from which to start
constructing a fireline. Used to minimize the chance of being flanked while line is being constructed.
Control line - ANSWERSAn inclusive term for all constructed or natural barriers and treated fire edges used to
contain a fire
Fireline - ANSWERSThe part of a containment or control line that is scraped or dug to mineral soil
Mop-up - ANSWERSExtinguishing or removing burning material near control lines, felling snags, and trenching
logs to prevent rolling after an area has burned, to make a fire safe, or to reduce residual smoke
, Contained - ANSWERSThe status of a wildfire suppression action signifying that a control line has been
completed around the fire, and any associated spot fires, which can reasonably be expected to stop the fire's
spread.
Controlled - ANSWERSThe completion of control line around a fire, any spot fires, and any interior islands to
be saved. Burn out any unburned area adjacent to the fire side of the control lines. Cool down all hot spots
that are immediate threats to the control line, until the lines can reasonably be expected to hold under the
foreseeable conditions
Chain - ANSWERSUnit of measure in land survey. 1 chain=66 feet. 80 chains=1 mile. 10 square chains=1 acre.
3 elements of the fire triangle - ANSWERSFuel to burn
Air to supply oxygen for the flame
Heat to start and continue the combustion process
3 methods of heat transfer - ANSWERSRadiation, convection, conduction
Radiation - ANSWERSRadiant heat can dry surrounding fuels and sometimes ignite them. Like standing close to
a camp fire warms you up.
Convection - ANSWERSThink of this as a smoke column above the fire. Occurs when lighter warm air moves
upward. The hot gases and embers which compose the smoke column can dry and ignite other fuels
Conduction - ANSWERSHeat is conducted from one fuel particle to another by direct contact.
When is a fire controlled? - ANSWERSWhen its expected to hold under any foreseeable conditions
Topography - ANSWERSThe configuration of the earth's surface including its relief and the position of its
natural and man-made features
Aspect - ANSWERSThe direction a slope is facing (its exposure in relation of the sun
Point of origin - ANSWERSThe precise location where a competent ignition source came into contact with the
material first ignited and sustained combustion occurred.
Head of a fire - ANSWERSThe side of the fire having the fastest rate of spread
Flank of a fire - ANSWERSThe part of a fire's perimeter that is roughly parallel to the main direction of spread.
Rear of a fire - ANSWERSPortion of a fire spreading directly into the wind or down slope. Opposite the head.
Slowest spreading portion of a fire edge. Also called the heel
3 main objectives to fight a fire - ANSWERSAnchor, Flank, Pinch
Fire perimeter - ANSWERSEntire outer edge of a fire
Fingers of a fire - ANSWERSLong narrow extensions of a fire projecting from the main body
Pockets of a fire - ANSWERSUnburned indentations in the fire edge formed by fingers or slow burning areas
Island - ANSWERSArea of unburned fuel inside the fire perimeter
Spot fire - ANSWERSFire ignited outside the perimeter of the main fire by a fireband
Smoldering - ANSWERSFire burning without flame and barely spreading
Creeping fire - ANSWERSFire burning with a low flame and spreading slowly
Running fire - ANSWERSBehavior of a fire spreading rapidly with a well defined head
,Spotting - ANSWERSBehavior of a fire producing sparks or embers that are carried by the wind and which start
new fires beyond the zone of direct ignition by the main fire
Torching - ANSWERSThe burning of foliage of a single tree or a small group of trees from the bottom up
Crown fire - ANSWERSFire that advances from top to top of trees or shrubs more or less independent of
surface fire. Sometimes classes as running or dependent to distinguish the degree of independence from the
surface fire.
Flare up - ANSWERSAny sudden acceleration in the rate of spread or intensification. Relatively short-duration.
Junipers cause a lot of these.
Firewhirl - ANSWERSSpinning vortex column of ascending hot air and gases rising from a fire and carrying aloft
smoke, debris, and flame. Can move all over and are unpredictable.
Backing fire - ANSWERSThat portion of the fire with slower rates of spread. Also called the heel
Flaming front - ANSWERSThat zone of a moving fire where the combustion is primarily flaming. Light fuels
typically have a shallow flaming front. Heavy fuels have a deeper front.
Anchor point - ANSWERSAn advantageous location, usually a barrier to fire spread, from which to start
constructing a fireline. Used to minimize the chance of being flanked while line is being constructed.
Control line - ANSWERSAn inclusive term for all constructed or natural barriers and treated fire edges used to
contain a fire
Fireline - ANSWERSThe part of a containment or control line that is scraped or dug to mineral soil
Mop-up - ANSWERSExtinguishing or removing burning material near control lines, felling snags, and trenching
logs to prevent rolling after an area has burned, to make a fire safe, or to reduce residual smoke
, Contained - ANSWERSThe status of a wildfire suppression action signifying that a control line has been
completed around the fire, and any associated spot fires, which can reasonably be expected to stop the fire's
spread.
Controlled - ANSWERSThe completion of control line around a fire, any spot fires, and any interior islands to
be saved. Burn out any unburned area adjacent to the fire side of the control lines. Cool down all hot spots
that are immediate threats to the control line, until the lines can reasonably be expected to hold under the
foreseeable conditions
Chain - ANSWERSUnit of measure in land survey. 1 chain=66 feet. 80 chains=1 mile. 10 square chains=1 acre.
3 elements of the fire triangle - ANSWERSFuel to burn
Air to supply oxygen for the flame
Heat to start and continue the combustion process
3 methods of heat transfer - ANSWERSRadiation, convection, conduction
Radiation - ANSWERSRadiant heat can dry surrounding fuels and sometimes ignite them. Like standing close to
a camp fire warms you up.
Convection - ANSWERSThink of this as a smoke column above the fire. Occurs when lighter warm air moves
upward. The hot gases and embers which compose the smoke column can dry and ignite other fuels
Conduction - ANSWERSHeat is conducted from one fuel particle to another by direct contact.
When is a fire controlled? - ANSWERSWhen its expected to hold under any foreseeable conditions
Topography - ANSWERSThe configuration of the earth's surface including its relief and the position of its
natural and man-made features
Aspect - ANSWERSThe direction a slope is facing (its exposure in relation of the sun
