Scientists find 79-million-gallon reservoir beneath Yellowstone's Old Faithful

Old Faithful Geyser EruptionPhoto: CanvaOld Faithful may be the world’s most famous geyser, but until recently, no one had a clear picture of the “plumbing” that powers its eruptions. In a landmark 2017 studytitled 'Anatomy of Old Faithful From Subsurface Seismic Imaging of the Yellowstone Upper Geyser Basin', University of Utah scientists deployed 133 small, portable seismometers around Old Faithful and nearby Geyser Hill for two weeks, listening to the faint hum of the ground between eruptions. By turning everyday micro-vibrations, caused by wind, water, tourists, and the geyser’s own boiling, into a usable signal, the team mapped a hidden reservouir of hot water beneath the surface. Their analysis suggests the reservoir can hold roughly 300,000 cubic meters of water, or about 79 million