Geysers have loops in their plumbing

Early morning at one of several geyser fields in the El Tatio region of Chile's Atacama desert. Michael Manga photo. Geysers like Old Faithful in Yellowstone National Park erupt periodically because of loops or side-chambers in their underground plumbing, according to recent studies by volcanologists at the University of California, Berkeley. Volcanologist Michael Manga and student Esther Adelstein use a laboratory geyser they built to explain how geysers like Old Faithful work. Video by Roxanne Makasdjian and Phil Ebiner, with geyser footage by Eric King and Kristen Fauria. The key to geysers, said Michael Manga, a UC Berkeley professor of earth and planetary science, is an underground bend or loop that traps steam and then bubbles it out slowly to heat the water column above until it is just short of boiling. Eventually, the steam bubbles trigger sudden boiling from the top of the column, releasing pressure on the water below and allowing it to boil as well.