Sarah Henton and Melissa Pfeffer trying to collect samples "black scum" that floats on the surface of the main pool at Shrub mud volcano. Temperature on this day was 44.1°C; about 5°C higher than in 2005.
Image courtesy of AVO/USGS.
Please cite the photographer and the Alaska Volcano Observatory / U.S. Geological Survey when using this image. Full Resolution.