Dean M. Chriss
Photography
Snag and Algae, Grand Prismatic Spring, Wyoming
(Click image to enlarge)
Yellowstone's Grand Prismatic Spring is the largest hot spring in the United
States and the third largest in the world. The hot water plumbing of these
enormous thermal areas changes over time, moving hot water to new places and
diverting it away from others. The tree shown in this photograph was once alive
and vibrant, but died when its roots were surrounded by hot water. The
land area shown in this photograph, except the brightest areas near the top, is
covered with shallow hot water. Hydrothermal features like this are
habitats for a wide variety of heat loving microscopic organisms called
thermophiles. The most visible exist in the mats of algae and bacteria that give
color to hot springs and pools. Colors can range from nearly white to yellow to
dark reds, greens, and browns, and different colors are associated with
different temperatures. You can read more about this
here
and see a more colorful photograph
of Grand Prismatic Spring here.