Some geysers have predictable eruptions that make them ideal for study. Understanding geyser eruption dynamics can provide insight into other intermittent natural processes, such as volcanic eruptions, but most studies of geysers have focused on the processes that trigger geyser eruption.
The eruption jet dynamics are less well characterized.
In one of the most comprehensive studies of geyser eruption dynamics to date, over the course of a 4-day experiment at Lone Star Geyser in Yellowstone National Park, Karlstrom et al. measured water discharge, acoustic emissions, and infrared intensity, and recorded visible and infrared video of the geyser. They selected Lone Star Geyser because it has relatively frequent and vigorous eruptions, about every 3 hours.
They find that the eruption cycle has four distinct phases: first, a main eruptive phase with liquid and steam fountaining and maximum jet velocities of 16 to 28 meters per second (36 to 63 miles per hour), concluded by a period in which the ratio of erupting steam to liquid increases; second, a post-eruption phase with no discharge but periodic acoustic and infrared emissions; third, a recharge period during which the geyser cone refills; and fourth, a "preplay" period characterized by a series of 5- to 10-minute pulses of steam, periodic acoustic emissions, and small volumes of liquid water discharge.
The authors also estimate the total heat output from the geyser to be about 1.4 megawatts, which is less than 0.1 percent of the total heat output from Yellowstone caldera.
Article: Leif Karlstrom, Shaul Hurwitz, Fred Murphy and Malcolm J. S. Johnston:, Robert Sohn, Jean Vandemeulebrouck, Maxwell L. Rudolph, Michael Manga, R. Blaine McCleskey: U.S. Geological Survey, Boulder, Colorado, 'Eruptions at Lone Star Geyser, Yellowstone National Park: Energetics and eruption dynamics', Journal of Geophysical Research-Solid Earth, doi:10.1002/jgrb.50251