Since 2017, California has experienced a succession of wildfires that caused historic levels of destruction. At the start of this year, U.S. firefighters were helping battle the Australian bushfires for the first time in a decade. Presently, teams are diligently working to suppress wildfires raging up and down the West Coast, from Washington and Oregon to California.

Given the extreme and unpredictable nature of these incidents, first responders must use a variety of specialized tactics to beat back the blazes. Understanding what happens on the fireground and how skilled firefighters manage and suppress these outbreaks year after year is an important way to recognize their efforts and honor their sacrifices.

Establishing control lines to manage the spread of wildfires

Firefighters strategically create and use boundaries to keep wildfires in containment. These can be natural boundaries, such as rivers, or engineered ones where teams manipulate the landscape to remove any potential fire fuel sources and limit its spread.

Creating a true fire line involves stripping the land down to the soil, but teams often create preliminary scratch lines when they need to work quickly. They'll also establish temporary wet lines by applying water or fire-retarding chemicals to the ground. Explosives are also used to quickly taking down flammable trees and brush.

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Suppressing flames and embers to keep wildfires in check

When faced with a sizeable wildfire, firefighting teams have to make tactical decisions about how, when and where they will work to extinguish the flames. They will work on the fireground and conduct aerial attacks to keep the fire under control.

Often, the first step will be hotspotting. This involves assessing the overall behavior of the fire and suppressing specific points that pose the highest threat of spreading quickly or causing damage. Teams will also knock down or reduce the heat and flames in particularly active parts of the fire's outer edge using water, soil and fire-retarding chemicals.

Once areas have been contained, firefighters will still work diligently to ensure that the control line remains intact. A mop-up is when embers and burning materials near the control line are removed or extinguished. Cold trailing is a technique where firefighters inspect the "dead" fire edge for any signs of heat. They'll often feel around with their hands to locate and dig out any embers or hot spots.

Using strategic, controlled fires to support containment efforts

It might be surprising to learn that firefighters actually light small fires as a way to manage larger blazes. For instance, teams might conduct a burn out within a new control line to use up the available fuel and bolster the effectiveness of the created boundary. Similarly, firefighters will create backfires downwind of a major fire to change its direction. These advanced techniques require a great deal of experience and careful attention the wildfire's movements.

Initiating prescribed fires to promote healthy ecosystems and reduce risk

Wildfires are a force of nature, and they play a role in keeping ecosystems healthy. A significant amount of scientific research goes into understanding that role and how it can be accomplished in a contained manner that doesn't endanger human lives. The U.S. Forest Services explains that strategic prescribed fires throughout the year help maintain the right balance and reduce the risk of unwanted, uncontrolled outbreaks.

After a major wildfire is successfully extinguished, the work continues with Burned Area Emergency Response efforts. Teams of soil scientists, vegetation specialists, hydrologists, engineers and other experts will evaluate a scorched area. Their assessment will help determine how to stabilize and rehabilitate the environment so it remains safe for the plants, animals and people that inhabit the region.