Schematic model showing a cross section of Old Faithful's plumbing
Schematic model showing a cross section of Old Faithful's plumbingSchematic model showing a cross section of Old Faithful's plumbing system as determined from seismic studies. The red circles (t0-t3) show the location of the tremor source over time, and how the tremor source migrates upward prior to an Old Faithful eruption. Times between red circles are based on a 93-minute eruption interval.