Thermal Photo showing stream flow in excess of 500 gallons

Figure 1. Thermal image displayed as an inset of the true-color photograph taken in the field. The photograph looks upstream from the mouth of a large spring, where flow is in excess of 500 gallons per minute. A thrust fault lines the base of the hill in background. The thermal image spans an area about 4 feet across. The unprocessed image (which shows the range of temperature in degrees Celsius) has not been calibrated to actual water temperature at this location. Image courtesy Kurt McCoy/USGS Virginia Water Science Center.