Guinness World Records 2018

Wildfires

EARTH

WILDFIRES

The picture above

shows a wildfire

in Brazil’s Cerrado

ecoregion. Such

conflagrations are

usually man-made,

but wildfires can

also start naturally.

Dry forest debris

can catch fire, and

lightning strikes may

ignite fires. There

are positive aspects

to less destructive

forest fires, however.

Old growth and

weeds are burned

off, stimulating

regeneration. Minerals

and nutrients are

released from burning

plants and returned

to the soil. Forest

canopies are opened

up too, allowing more

sunlight to reach

plants on the ground.

“Fire chaser” beetles (genus Melanophila) use their infra-red sensors to seek

out forest fires. Burnt trees have no chemical defences to attack their eggs.

10.1 million

Wildfires can start

from the spontaneous

combusting of

dead leaves, twigs

and branches

Lightning strikes can

ignite a wildfire under

certain conditions

Wildfires can

travel at speeds

of 14 mph

(23 km/h)

Earliest known wildfire

In Apr 2004, scientists from Cardiff University’s

School of Earth, Ocean and Planetary Science

(UK) found evidence that a low-intensity wildfire

began smouldering c. 419 million years ago, in

the Silurian period. The fire was likely started by

a lightning strike. The discovery was made while

the team was studying charred fossils of small

plants found in rocks near Ludlow, UK.

Longest-burning fire

The fire in a burning coal seam beneath Mount

Wingen in New South Wales, Australia, is believed

to have started 5,000 years ago. It ignited when

lightning struck the seam at the point where it

reached the Earth’s surface. Today, the fire is

burning around 100 ft (30 m) underground, as

it has slowly eaten away at the seam.

First use of a fire shelter

The last resort used by firefighters faced with

wildfires that have surrounded them is to build

a fire shelter. Designed to reflect heat, keep

out convective heat and contain breathable

air, they resemble a shallow one-person tent

and are deployed on the ground or in a dug-out

hollow. The earliest known use of a fire shelter

was noted by explorer William Clark in a journal

entry dated 29 Oct 1804. Reporting the outbreak

of a prairie wildfire near Fort Mandan in North

Dakota, USA, Clark related an incident in which an

American mother threw a “Green buffalow Skin”

[sic] over her son to protect him from the flames.

Most energy released by a burning tree

The heat content of any fire depends upon

wood density, resin, ash and moisture, but

the tree that produces the most heat when

burned is the osage-orange or horse-apple

(Maclura pomifera), a large deciduous shrub-

like plant belonging to the mulberry family,

and distributed widely across North America.

When burned, this species produces some

34.8 billion joules per 20% air-dried

moisture content cord. A cord is defined

as a piece of wood 4 ft wide by 4 ft high

by 8 ft long (1.21 m x 1.21 m x 2.43 m), with an

average 80 cu ft (2.2 m^3 ) of burnable wood,

the remainder being pockets of air.

Longest firebreak

A firebreak is a break in vegetation that acts

to block the progress of wildfires. Man-made

firebreaks are often created in the form of roads

strategically constructed in places at high risk

of wildfires. In 1931, construction began on the

Ponderosa Way on the western slope of the

Sierra Nevada Mountains in California, USA.

Eventually reaching a length of some 800 mi

(1,287 km) – around the same as the Rhine

river – the Ponderosa Way was built by around

16,000 members of the Civilian Conservation

Corps. In 1934 alone, the firebreak was

responsible for containing nine of the 11 large

wildfires that hit the region that year.

Most smokejumpers per country

Smokejumpers are elite firefighters who

are deployed to remote wildfires as soon

as they are identified. They are dropped by

parachute near a wildfire, along with their

equipment, including food and water to

make them self-sufficient for a day or two.

Once deployed, smokejumpers use chainsaws

and other equipment to cut down trees,

scrape away topsoil and create firebreaks.

Russia, which introduced smokejumpers

in around 1936, currently employs

approximately 4,000 of them.

Most coal fires underground (country)

China, the world’s largest producer

of coal, has hundreds of subterranean

fires across its coal belt. Some have been

burning for centuries. Around 20 million

tonnes (19.6 million tons) of coal per year

are destroyed and 10 times that amount

rendered inaccessible owing to the fires.

HIGHEST DEATH TOLL FROM A WILDFIRE

On 8 Oct 1871, forest fires ravaged north-east

Wisconsin and upper Michigan, USA, killing around

1,200 to 2,500 people. More than 1,500 sq mi

(3,885 km²) of forest and farmland were also

destroyed (see illustration, left).

Under certain circumstances, tornado-like

phenomena known as “fire whirls” can occur within

fires. They are caused by heat rising and forming

eddies. The highest death toll from a fire whirl

happened as a result of the Great Kanto Earthquake on 1 Sep

1923, which struck the Kanto region of Honshu in Japan (see

photograph, far left). Tragically, 38,000 people were incinerated by

a fire whirl while packed into a former army clothing depot in Tokyo.

A: Buildings in its path were blown

up, to stop the flames spreading

acres (40,873,249,866 m^2 )

of the USA were destroyed

by wildfires in 2015 –

equivalent to more than...

20,000

American

football fields

every day!

More than 80%

of wildfires

are begun by

humans – either

deliberately or by

accident

The area devastated

by the 1871 wildfire in

Wisconsin and Michigan

(see below right) was

slightly larger than

Belgium – or twice

the^ size of Kuwait.

Q: How was the Great

Fire of London in 1666

finally stopped?