A firestorm is a conflagration which attains such intensity that it creates and sustains its own wind system. It is most commonly a natural phenomenon, created during some of the largest bushfires and wildfires. Although the term has been used to describe certain large fires, the phenomenon's determining characteristic is a fire with its own storm-force winds from every point of the compass towards the storm's center, where the air is heated and then ascends.
The Oakland firestorm of 1991 was a large suburban wildland–urban interface conflagration that occurred on the hillsides of northern Oakland, California, and southeastern Berkeley over the weekend of October 19–20, 1991, before being brought under full control on October 23. The official name of this incident by Cal Fire is the Tunnel Fire. It is also commonly referred to as the Oakland Hills firestorm or the East Bay Hills fire. The fire ultimately killed 25 people and injured 150 others. The 1,520 acres destroyed included 2,843 single-family dwellings and 437 apartment and condominium units. The economic loss from the fire was estimated at $1.5 billion.
A controlled or prescribed (Rx) burn is the practice of intentionally setting a fire to change the assemblage of vegetation and decaying material in a landscape. The purpose could be for forest management, ecological restoration, land clearing or wildfire fuel management. A controlled burn may also refer to the intentional burning of slash and fuels through burn piles. Controlled burns may also be referred to as hazard reduction burning, backfire, swailing or a burn-off. In industrialized countries, controlled burning regulations and permits are usually overseen by fire control authorities.
The fire triangle or combustion triangle is a simple model for understanding the necessary ingredients for most fires.
A fuel ladder or ladder fuel is a firefighting term for live or dead vegetation that allows a fire to climb up from the landscape or forest floor into the tree canopy. Common ladder fuels include tall grasses, shrubs, and tree branches, both living and dead. The removal of fuel ladders is part of defensible space 'firescaping' practices.
This glossary of wildfire terms is a list of definitions of terms and concepts relevant to wildfires and wildland firefighting. Except where noted, terms have largely been sourced from a 1998 Fireline Handbook transcribed for a Conflict 21 counter-terrorism studies website by the Air National Guard.
A fire retardant is a substance that is used to slow down or stop the spread of fire or reduce its intensity. This is commonly accomplished by chemical reactions that reduce the flammability of fuels or delay their combustion. Fire retardants may also cool the fuel through physical action or endothermic chemical reactions. Fire retardants are available as powder, to be mixed with water, as fire-fighting foams and fire-retardant gels. Fire retardants are also available as coatings or sprays to be applied to an object.
Smouldering or smoldering is the slow, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a condensed-phase fuel. Many solid materials can sustain a smouldering reaction, including coal, cellulose, wood, cotton, tobacco, cannabis, peat, plant litter, humus, synthetic foams, charring polymers including polyurethane foam and some types of dust. Common examples of smouldering phenomena are the initiation of residential fires on upholstered furniture by weak heat sources, and the persistent combustion of biomass behind the flaming front of wildfires.
Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts depend on many factors such as the available fuel, the local atmospheric conditions, the features of the terrain, and the size of the wildfire. Because of this wildfire suppression in wild land areas usually requires different techniques, equipment, and training from the more familiar structure fire fighting found in populated areas. Working in conjunction with specially designed aerial firefighting aircraft, fire engines, tools, firefighting foams, fire retardants, and using various firefighting techniques, wildfire-trained crews work to suppress flames, construct fire lines, and extinguish flames and areas of heat in order to protect resources and natural wilderness. Wildfire suppression also addresses the issues of the wildland–urban interface, where populated areas border with wild land areas.
The Cerro Grande Fire was a prescribed-burn forest fire in Los Alamos, New Mexico, United States of America, that occurred in May of 2000. The fire started as a controlled burn on May 4, 2000, and became uncontrolled owing to high winds and drought conditions. Over 400 families in the town of Los Alamos, New Mexico, lost their homes in the resulting 58,000 acre fire. Structures at Los Alamos National Laboratory were also destroyed or damaged, although without loss or destruction of any of the special nuclear material housed there. No loss of human life occurred. The US General Accounting Office estimated total damages at $1 billion.
Established in 1917, the Presidio Fire Department provides primary emergency response to the Presidio of San Francisco.
Fire-retardant gels are superabsorbent polymer slurries with a "consistency almost like petroleum jelly." Fire-retardant gels can also be slurries that are composed of a combination of water, starch, and clay. Used as fire retardants, they can be used for structure protection and in direct-attack applications against wildfires.
A defensible space, in the context of fire control, is a natural and/or landscaped area around a structure that has been maintained and designed to reduce fire danger. The practice is sometimes called firescaping. "Defensible space" is also used in the context of wildfires, especially in the wildland-urban interface (WUI). This defensible space reduces the risk that fire will spread from one area to another, or to a structure, and provides firefighters access and a safer area from which to defend a threatened area. Firefighters sometimes do not attempt to protect structures without adequate defensible space, as it is less safe and less likely to succeed.
Wildfire suppression in the United States has had a long and varied history. For most of the 20th century, any form of wildland fire, whether it was naturally caused or otherwise, was quickly suppressed for fear of uncontrollable and destructive conflagrations such as the Peshtigo Fire in 1871 and the Great Fire of 1910. In the 1960s, policies governing wildfire suppression changed due to ecological studies that recognized fire as a natural process necessary for new growth. Today, policies advocating complete fire suppression have been exchanged for those who encourage wildland fire use, or the allowing of fire to act as a tool, such as the case with controlled burns.
The wildland–urban interface (WUI) is a zone of transition between wilderness and land developed by human activity – an area where a built environment meets or intermingles with a natural environment. Human settlements in the WUI are at a greater risk of catastrophic wildfire.
Wildfires are outdoor fires that occur in the wilderness or other vast spaces. Other common names associated with wildfires are brushfire and forest fire. Since wildfires can occur anywhere on the planet, except for Antarctica, they pose a threat to civilizations and wildlife alike. In terms of emergency management, wildfires can be particularly devastating. Given their ability to destroy large areas of entire ecosystems, there must be a contingency plan in effect to be as prepared as possible in case of a wildfire and to be adequately prepared to handle the aftermath of one as well.
The Soberanes Fire was a large wildfire that burned from July to October 2016 in the Santa Lucia Mountains of Monterey County, California. It destroyed 57 homes and killed a bulldozer operator, and cost about $260 million to suppress, making it at the time the most expensive wildfire to fight in United States history. At the fire's peak, over 5,000 personnel were assigned to the blaze. The fire was the result of an illegal campfire in Garrapata State Park. By the time it was finally extinguished, the fire had burned 132,127 acres (53,470 ha) along the Big Sur coast in the Los Padres National Forest, Ventana Wilderness, and adjacent private and public land in Monterey County, ranking it 18th on the list of the largest California wildfires in terms of acreage burned.
Fire adaptations are traits of plants and animals that help them survive wildfire or to use resources created by wildfire. These traits can help plants and animals increase their survival rates during a fire and/or reproduce offspring after a fire. Both plants and animals have multiple strategies for surviving and reproducing after fire. Plants in wildfire-prone ecosystems often survive through adaptations to their local fire regime. Such adaptations include physical protection against heat, increased growth after a fire event, and flammable materials that encourage fire and may eliminate competition.
The Ikes Fire was a 2019 wildfire that burned 16,416 acres (6,643 ha) in Grand Canyon National Park and Kaibab National Forest in Arizona. A lightning strike on July 25, 2019, was determined to be the cause. The Ikes Fire was also being utilized to fulfill its natural role within a fire-dependent ecosystem while providing for point protection of identified sensitive natural and cultural resources. Resource objectives included reducing hazardous fuels, promoting forest regeneration, improving wildlife habitat, and restoring more open forest understory. These objectives will lead to a healthier and more resilient landscape.
The 2020 Dome Fire was a large and ecologically destructive wildfire in the Mojave National Preserve in California's San Bernardino County. Caused by a lightning strike on August 15, the fire began near Cima Dome and exhibited rapid growth over the following 36 hours, aided by weather conditions and a lack of available firefighting resources. During this period the Dome Fire destroyed only 6 structures, but burned more than a quarter of the Cima Dome Joshua tree forest, one of the largest and densest populations of Joshua trees known in the world. The fire killed as many as 1.3 million Joshua trees. No injuries or fatalities were reported among firefighters or civilians. The fire cost $2.2 million to suppress, and burned 43,273 acres (17,512 ha) before being fully contained on August 24.
