Mop-up teams fight the fires that might flare up behind the fire line
Battling wildfires is an enormously involved process, and it continues on long after the walls of flame have been extinguished. The first goal of dealing with large wildfires is to contain them, creating a perimeter where there is no more fuel, or fire, to burn, keeping things from spreading further. Once that perimeter has been established, it needs to be maintained, which is where the mop-up teams go to work.
Mop-up teams are in charge of making sure fires don’t get restarted behind the fire line. Forest fires can burn hot enough to leave smoldering embers and ash buried under dirt and rocks, even without the presence of visible flames. Since a shift in the wind or hotter day can push these hidden heat sources back into the danger zone, mop-up teams have to carefully sift and dig through burned areas to make sure everything is really extinguished.
Rather than fire trucks, mop-up teams rely on a less mechanized tool set for their work. Pulaski, which are a sort of ax-pickax hybrid, is used to chop and break up soil and clumps of foliage. To see how hot soil may be at any particular location, these firefighters simply pull off a glove to feel the temperature with the back of their hand. If a hot spot is found, it might be “dry mopped” by mixing in cooler soil, or “wet mopped” by spraying additional water to cool things off.
While these teams shouldn’t be facing walls of flame when mopping up a burn site, they’re certainly not out for a picnic either. Firefighters may still deal with long, physically exhausting shifts as they dig and hack their way through smoking forests. Burned trees are often structurally unsound, and prone to collapse, possibly revealing fires hidden in their branches or trunks. Ash pits are another common hazard, as trees and roots that have burned away may leave hidden cavities underground. As a firefighter walks through the area, they may suddenly find themselves waist deep in hot ash, as the ground beneath their feet collapses.
Even after the mop-up work is done, the fire management still isn’t complete. To help get burned areas back to normal as quickly as possible, teams of soil specialists move in to assess the damage, and prescribe next steps to rehabilitate the lost flora. Some of this is to restore the woods quickly, but a more immediate concern is to fend off erosion and possible mudslides, as the burned plants and their stabilizing root structures will be sorely missed at the next windy or rainy day.
Source: Unglamorous ‘Mop-Up’ Duty Keeps Fires Extinguished by Sharon McNary, KQED News