How often does Old Faithful erupt?
Old Faithful erupts on average every 92 minutes. Intervals can range from as short as 35 minutes to as long as 120 minutes, depending on the duration of the prior eruption.
Questions about Old Faithful
Short answers, pulled from the story.
When was Old Faithful named and who named it?
Old Faithful was named on the 18th of September, 1870, by members of the Washburn-Langford-Doane Expedition. It was the first geyser in Yellowstone National Park to receive a name.
How high does Old Faithful shoot water?
Old Faithful's eruptions reach heights of 106 to 185 feet, with an average height of 145 feet. Each eruption discharges between 3,700 and 8,400 US gallons of boiling water and lasts between one and a half and five minutes.
Why is Old Faithful so predictable compared to other geysers?
Old Faithful is not connected to any other thermal features in the Upper Geyser Basin, meaning its underground water supply operates as an isolated system. This insulation from neighboring features prevents outside disturbances from disrupting its eruption cycle.
Have earthquakes affected Old Faithful's eruption intervals?
Yes. After the Borah Peak earthquake in central Idaho in October 1983, Old Faithful's eruption intervals noticeably lengthened. The average interval, which was 66.5 minutes in 1939, has climbed to around 90 minutes since 2000, a change researchers attribute partly to seismic activity altering subterranean water levels.
How hot is the water inside Old Faithful's conduit?
Probes lowered to a depth of 72 feet between 1983 and 1994 recorded water temperatures of 244 degrees Fahrenheit, matching measurements taken in 1942. Superheated steam entering the conduit reached temperatures as high as 265 degrees Fahrenheit.