Can thermoluminescence be used to determine soil heating from a wildfire?

The Silverado wildfire occurred from September 12 to 20, 2014, burning 960 acres in Orange County, California. Soil samples from within the burn area were obtained and the thermoluminescence (TL) properties of those samples were compared against a control sample to understand wildfire heating. We performed a series of experiments investigating the degree to which the control differed from the wildfire soil samples. This work showed that soil heated by a wildfire had a distinctly different glow curve shape than the unburned soil sample. Moreover, it was possible to see changes in the TL signal as a function of soil depth in wildfire-heated samples. Our experiments suggest that minimal soil heating occurred below approximately 10 cm. Estimates of wildfire temperatures, however, were nuanced.