Photograph compared with thermal image showing a geologist sampling...

This image shows an HVO geologist sampling the lava that was seeping out of the interior of the rootless shield. The lava was placed in a bucket of water to quench the sample. The top frame is a normal photograph, while the bottom frame is a thermal image taken within a fraction of a second of the photograph. As the thermal image shows, the incandescent interior of the flow, which is exposed as lava clinker spalls off, exceeds 1000 degrees Celsius (1800 degrees Fahrenheit). The geologist is shielding his face from the radiant heat.