Geyser Awakens After 4.6 Quake at Yellowstone

A geyser that has not been active for more than 80 years has begun erupting again and three other geysers and a number of hot springs have shown significant changes in activity since a March 26 earthquake in Yellowstone National Park, a park scientist reports.

The 4.6 magnitude quake near the Norris Geyser Basin was not of a particularly uncommon strength for Yellowstone, the site of a 600,000-year-old volcanic caldera. But it has had unusual effects, said Rick Hutchinson, a research geologist with the National Park Service.

The Monarch Geyser, which used to send water shooting up close to 200 feet but had not erupted since 1913, has become active, periodically expelling rocks, mud and water to a height of about 15 feet, Hutchinson said. The temperature of the water now often is at the boiling point.

Also stirring to life after 15 years of inactivity has been the Ledge Geyser, which has begun shooting water up to 130 feet high at a 30-degree angle every week or 10 days, he said.

The geologist said that the Steamboat Geyser, the park’s tallest, shooting water nearly 400 feet high, has had a decrease in some of its side splashing.

“Since the earthquake, the amount of splashing has diminished in frequency and intensity,” Hutchinson said. “Now, there’s virtually no runoff, whatsoever, whereas in the past it occurred every two to five minutes.”

Monarch, Ledge and Steamboat are in the Norris Basin about 30 miles north of Old Faithful Geyser, the park’s most famous, which was not affected by the quake.

A two-week resurgence of activity was also noted at the Morning Geyser, in the Fountain Paintpot area of the Lower Geyser Basin, just eight miles from Old Faithful, Hutchinson said.

The scientist said that the water level suddenly dropped after the earthquake in some hot springs, while temperatures rose in others.

All of the geysers with changed activity are within easy walking distance of paved roads and accessible to park visitors.

Altogether, Yellowstone has between 200 and 250 active geysers in any given year. Magma or lava deeply underlying the park is believed to heat water through a vast underground plumbing system, causing the activity.

Hutchinson said that the last earthquake activity to cause noticeable changes in Yellowstone geysers and hot springs was “sympathetic” temblors that followed the 1992 Landers earthquake in California, hundreds of miles away.