Black Sand Pool Hot Spring
June 03, 2004
The photo above shows the Black Sand Pool in Yellowstone National Park, Wyoming. Unlike their more famous hydrothermal counterparts, geysers, hot springs are non-erupting geo-thermal features. Whereas geysers have constricted areas in the sub-surface plumbing, hot springs typically are larger and more open, allowing convection and greater circulation of heated water.
Over the years several of the famous hot springs have succumbed to vandalism. Coins and other debris have clogged the water circulation causing dramatic cooling of these springs. Black Sand Pool is off the paved trail in the Upper Geyser Basin. Surrounded by obsidian sand, this pool shows a rich blue color that indicates fewer bacterial colonies and higher water temperatures.