IS OLD FAITHFUL A STRANGE ATTRACTOR

Geysers are systems that exhibit hydrothermal eruptive behavior at irr egular and, occasionally, relatively regular intervals. Because geyser dynamics are governed by strongly nonlinear differential equations, i t is reasonable to expect that these systems are capable of displaying chaotic behavior. Geyser dynamics are shown to be analogous to a simp le conceptual model known to exhibit chaotic behavior. State space rec onstructions of eruption interval data then show that the geyser Old F aithful erupts at chaotic intervals. Establishing the system as chaoti c explains the inability to predict long-term eruptive behavior of Old Faithful.