Caldera chronicles: Understanding what's under your feet in hydrothermal areas

Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week’s contribution is from Jeff Havig, researcher in Earth and Planetary Science, and Plant and Microbial Biology, at the University of Minnesota.

When visiting Yellowstone National Park you may spend time exploring places where neutral to alkaline pH hot springs (those with pH values that are from around 7 — or neutral — to approaching 10 — about the value of bleach) are dominant features, precipitating silica (SiO2) to produce sinter deposits. This includes the Upper Geyser Basin (where Old Faithful and dozens of its geysing compatriots reside), the Midway Geyser Basin (home of Grand Prismatic Spring), the Lower Geyser Basin, and the West Thumb area, to name a few of the most popular.

While the charismatic geysers and bubbling hot springs may immediately draw the eye and consume your focus, take a moment to look at the bleach-white siliceous sinters that surround the springs and geysers. The sinters form due to dissolved solids in the hot spring water precipitating as the thermal waters cool. To the naked eye, they may not seem all that exciting, but when we use imaging techniques to zoom in

View Source