50 Fun Facts About Wildfires

Roughly what share of wildfires in the United States are started by human activity?

Over 85% of US wildfires are human-started, led by campfires, power-line failures and equipment sparks; arson may account for over 20% of those.

Which of these is listed as a natural cause of wildfire ignition?

Sparks from rock falls round out the list of natural igniters alongside lightning, volcanic eruptions and spontaneous combustion.

What is a fire that burns suspended material at the treetop level called?

A crown fire burns suspended material — needles, leaves and branches — at canopy level; ignition of the canopy is termed crowning and depends on canopy density, height and continuity.

Ground fires that smolder slowly for months are typically fed by what?

Ground fires are fed by peat, buried roots and duff and can smoulder for months; the 1997 Kalimantan peat fires started after the Mega Rice Project drained and dried the peatland.

Fires that carry flames from low vegetation into the tree canopy via small trees and vines are called what?

Ladder fires carry flames from low vegetation into the canopy via small trees, downed logs and vines; invasive climbers such as kudzu and Old World climbing fern encourage them.

Together with heat and fuel, which element completes the fire triangle needed for a wildfire?

Oxygen completes the fire triangle with heat and fuel; high moisture stops ignition because energy goes into evaporating water before the fuel reaches its fire point.

Roughly how fast can a wildfire advance through grassland?

Wildfires can advance at about 22 km/h (14 mph) through grassland, roughly double the 10.8 km/h forward rate of spread typical in forests.

What is it called when wind carries burning embers ahead of the fire front to start new fires?

Spotting is when wind carries burning embers ahead of the front to ignite new fires; in Australian bushfires, spot fires have been recorded as far as 20 km from the main front.

Large wildfires can generate spinning columns of flame with tornado-like force at speeds above what?

Large wildfires can spawn fire whirls, spinning columns of flame with winds above 80 km/h (50 mph); together with pyrocumulus clouds and strong convection columns they signal extreme fire behaviour.

US wildfire suppression operations are organised around a 24-hour 'fire day' that begins at what time?

The US 24-hour fire day begins at 10:00 a.m., when daytime warmth drives intensity up; burn rates of smouldering logs can be five times higher by day thanks to lower humidity and stronger winds.

Roughly what share of Australia's land mass burned in the record 1974-75 wildfire season?

About 117 million hectares, roughly 15% of Australia's land mass, burned in the 1974–75 season; most were remote, low-intensity grassland fires that caused few deaths and limited property damage.

Over the past century, roughly what share of global carbon emissions have come from wildfires?

Wildfires have accounted for roughly 20–25% of global carbon emissions over the past century; fires worldwide release around 2 billion tonnes of carbon a year, though regrowth reabsorbs much of it.

Aerial fire retardants use ammonium phosphates and sulfates, the same agents found in what?

Retardant salts — ammonium phosphates and sulfates — are the same agents used in fertilizers, which is why retardant washing into streams or lakes can cause eutrophication.

Communities in the Philippines maintain fire lines of what width between the forest and their village?

Philippine villages keep fire lines 5 to 10 metres wide between the forest and the settlement, and villagers patrol them during the summer months and dry seasons.

Charcoal fossils of which giant organism are the earliest evidence of wildfire on Earth?

Charcoalified fragments of Prototaxites, a fungus that grew up to 8 metres tall, found in Late Silurian rocks from about 420 million years ago, are the earliest evidence of wildfire.

Charred peaks on Lepidodendron forests from which geological period are evidence of ancient crown fires?

Charred crowns on Carboniferous Lepidodendron forests, about 300 million years ago, point to ancient crown fires; Jurassic gymnosperm forests by contrast show frequent, light surface fires.

Which president launched a 1937 fire prevention campaign that later featured Uncle Sam and Disney's Bambi?

Franklin D. Roosevelt launched a nationwide fire-prevention campaign in 1937 stressing human carelessness; later posters used Uncle Sam, Bambi characters and the Forest Service's bear mascot.

Which invasive tree, introduced to California, has increased wildfire intensity there?

Eucalyptus, brought to California from Australia in the 1850s, sheds oily bark and leaves that intensify wildfires; invasive gamba grass plays a similar role in northern Australia.

Early fire lookout towers reported fires by telephone, heliograph and what living messenger?

Lookouts locate smoke with an Osborne Fire Finder and also plot lightning strikes to watch for later ignition.

What is the sighting device in a lookout tower, used to pinpoint the bearing of a smoke column, called?

The Osborne Fire Finder, devised by William Osborne of the US Forest Service around 1911, is a rotating sighting ring over a map that gives the bearing of a smoke column; the tower's small room is the cab.

Smokejumpers, wildland firefighters who mount the initial attack on remote fires, reach them how?

Smokejumpers parachute into remote fires to attack them while they are still small; the United States has used them since 1940, and Russia's Avialesookhrana runs the world's largest smokejumper force.

The first operational smokejumper fire jumps in the US were made in July 1940 in which national forest?

Rufus Robinson and Earl Cooley made the first operational fire jump on 12 July 1940 at the Marten Creek fire in Idaho's Nez Perce National Forest, flying from the Ninemile base near Missoula.

How many smokejumpers and firefighters died in the 1949 Mann Gulch fire in Montana?

13 men — twelve smokejumpers and a fire guard — died at Mann Gulch on 5 August 1949; foreman Wagner Dodge survived by lighting an escape fire and lying in its burned patch as the blaze passed.

Which author's posthumously published book Young Men and Fire investigated the Mann Gulch fire?

Maclean, a University of Chicago English professor, also wrote A River Runs Through It.

Whose slogan was updated in April 2001 from 'Only You Can Prevent Forest Fires' to '...Prevent Wildfires'?

Smokey Bear's new wording acknowledged big outbreaks in grasslands and made clear he was not against prescribed burns.

In which year did the US Forest Service authorise its bear mascot, now counted as his birthday?

The Forest Service authorised Smokey Bear on 9 August 1944, the date kept as his birthday; artist Albert Staehle delivered the first poster that October, showing Smokey pouring water on a campfire.

The living mascot cub of the US fire-prevention campaign was rescued from a 1950 wildfire in which state?

The cub was found clinging to a burned tree after the Capitan Gap fire in New Mexico's Lincoln National Forest in May 1950; with burned paws, he was first nicknamed Hotfoot Teddy.

The Forest Service's mascot bear got so much mail that in 1964 he was given what?

Smokey was given his own ZIP code, 20252, in 1964, when he was receiving more than 13,000 letters a week; the live bear at the National Zoo was famous for loving peanut butter sandwiches.

The cones of which conifer are sealed with resin that only melts in a fire, releasing the seeds?

Lodgepole pine cones are sealed with resin that melts at around 45–60 °C in a fire, releasing seeds onto the cleared ground; this heat-triggered release, pyriscence, is the best-studied form of serotiny.

Which shade-intolerant tree needs fire to open gaps in the canopy so its seedlings can compete?

Giant sequoia seedlings need bare mineral soil and full sun; without fire, shade-tolerant white fir and incense cedar crowd them out beneath a closed canopy.

Fire-tolerant plants that regrow from surviving tissue after a burn are called what?

Resprouters regrow from surviving tissue: after an Australian bushfire the Mountain Grey Gum sends out epicormic shoots along the whole trunk, fed by energy stored in its roots.

Which southeastern US ecosystem had the highest fire frequency, burning once a decade or more?

Longleaf pine savanna historically burned every one to ten years; without fire, deciduous trees invade and shade out both the pines and the orchid- and pitcher-plant-rich understory.

Which invasive grass has increased fire frequency in the western United States?

Cheatgrass (Bromus tectorum), an annual from Eurasia, dries early and carpets the Great Basin with fine fuel, creating a feedback loop of more fire, more cheatgrass, more fire.

The deadliest wildfire in recorded history struck which US state on 8 October 1871?

The Peshtigo fire in north-eastern Wisconsin killed an estimated 1,500 to 2,500 people and burned about 1.2 million acres on both sides of Green Bay, including parts of Door County.

The Peshtigo blaze is largely forgotten because it shared a day with which famous disaster?

The Great Chicago Fire broke out the same night, 8 October 1871, and took the headlines; Holland, Manistee and Port Huron in Michigan also burned that day.

The Great Fire of 1910, or Big Burn, scorched about three million acres mainly in which two states?

The Big Burn of 20–21 August 1910 swept about three million acres of Idaho and Montana, plus part of Washington, killed 87 people and cemented the young Forest Service's fire-suppression mission.

During the 1910 Big Burn, Ranger Ed Pulaski saved most of his crew by herding them into what?

Pulaski herded about 45 men into an abandoned mine tunnel near Wallace, Idaho, and held his pistol on anyone who tried to flee; five died inside, and the site is now listed as the Pulaski Tunnel.

Approximately what percentage of Yellowstone National Park burned in the fires of 1988?

The 1988 fires burned about 793,000 acres, roughly 36% of Yellowstone; on 8 September the entire park was closed to non-emergency personnel for the first time in its history.

From 1972, Yellowstone let lightning-caused blazes burn under controlled conditions as what?

Under Yellowstone's 1972 natural-fire policy, lightning fires were allowed to burn as 'prescribed natural fires'; between 1972 and 1987 only 235 such fires burned a modest 33,759 acres.

Which hot, dry winds drive Southern California's autumn wildfires?

Santa Ana winds are hot, dry north-easterlies that blow from the Great Basin toward the Southern California coast in autumn, drying fuels and fanning blazes such as the 2017 Thomas Fire.

Australia's Black Saturday bushfires of 7 February 2009 killed how many people in Victoria?

Black Saturday killed 173 people in Victoria, Australia's deadliest bushfire disaster; as many as 400 separate fires were recorded that day, and a Royal Commission under Justice Bernard Teague followed.

What temperature did Melbourne reach on Black Saturday, 7 February 2009, then a city record?

Melbourne hit 46.4 °C (115.5 °F) on 7 February 2009, its highest reading on record at the time; with winds above 100 km/h the Forest Fire Danger Index passed 200, beyond Black Friday 1939 and Ash Wednesday 1983.

Australia's 2019-20 bushfire season is widely known by what name?

Black Summer burned more than 24 million hectares, and an estimated three billion terrestrial vertebrates were killed or displaced.

Failed hardware from which utility ignited California's deadliest wildfire, the 2018 Camp Fire?

A worn hook on a Pacific Gas and Electric (PG&E) transmission line started the Camp Fire; PG&E filed for bankruptcy in January 2019 and in 2020 pleaded guilty to 84 counts of involuntary manslaughter.

Which town in Butte County was mostly destroyed by the Camp Fire in November 2018?

The Camp Fire destroyed most of Paradise, a town of about 26,000 in the Sierra foothills, killing 85 people, displacing over 50,000 and destroying more than 18,000 structures.

A towering thunderstorm cloud generated by the heat of a wildfire is called what?

A pyrocumulonimbus is a fire-generated thunderstorm cloud that can reach the lower stratosphere and produce lightning, hail and even tornadoes, sometimes dousing the fire that made it.

Canada's record-breaking 2023 wildfire season burned roughly how many hectares?

About 18 million hectares burned in Canada in 2023, more than double the previous record season; smoke plumes degraded air quality as far away as the US East Coast and western Europe.

Firebreaks were used for wildfire protection as early as the 14th century on which Mediterranean island?

Sardinia used firebreaks for wildfire protection as early as the 14th century; centuries later, explorers from HMS Beagle recorded Aboriginal Australians using fire for clearing and hunting, later dubbed fire-stick farming.

At roughly what temperature does wood start to pyrolyse, releasing the flammable gases that actually burn in a wildfire?

230 C (450 F) is where wood's pyrolysis releases flammable gases; heat radiating ahead of a fire front can warm the air to about 800 C, pre-drying fuels before the flames arrive.

Satellites have traced wildfire smoke plumes staying intact for distances exceeding how far?

1,600 km, or 1,000 miles, is how far satellites have traced smoke plumes intact; Canadian and US wildfires together burn an average of about 54,500 square kilometres a year.