By Wendy Corr, Cowboy State Daily
Despite the destructive force of the flooding in Yellowstone National Park on June 13, the complex system of natural water “pipes” that run just under the surface and feed the numerous geysers in the Park were largely unaffected.
That’s according to Mike Poland, Scientist-in-Charge of the Yellowstone Volcano Observatory. But he did note that the flood on June 13 was the most significant event of its kind in the recorded history of Yellowstone National Park.
Biggest Flood
Poland said the stream gauge on the Yellowstone River at Corwin Springs, just north of the park, has been recording data since 1892.
“The previous high watermark at that gauge was 11 ½ feet, and that occurred in 1918, along with the flow rate of about 32,000 cubic feet per second,” Poland reported. “But on June 13 at that gauge, that record high was shattered, as the flood level reached 14 feet and the flow rate was in excess of 50,000 cubic feet per second.”
More Geyser Activity
Poland said scientists have been studying geyser activity in Yellowstone National Park since the 1870s, and research has shown that a year with higher rain and snowfall can increase the frequency of geyser eruptions.
“When we look back at the long record, for example, of Old Faithful eruptions, usually with more precipitation we see a slightly more frequent eruptive interval, and the time between eruptions decreases slightly,” Poland said. “It’s not much, maybe a few minutes, but it is statistically significant.”
Poland said only time will tell whether or not that frequency will increase as a result of the precipitation in June – but any influence would be very subtle.
“We’re not talking like Old Faithful is going to go from erupting every 90 minutes to every 60 minutes,” he said. “These are sort of like, a few minutes here or there. But it’s statistically significant. We can actually see the effects, so that you can tie it to whether the time between eruptions is slightly less than drier years.”
Poland said that most of the water that feeds the geyser system comes from beneath, and doesn’t necessarily percolate down from above – but if there were to be a severe enough drought, Yellowstone’s geyser system might be affected.
“There was a Yellowstone climate assessment that came out, I think it was last year, called the Greater Yellowstone Climate Assessment,” Poland said. “And one of the consequences of changing climate that that report cited was, if there’s less precipitation, and droughts get worse in the region, it is possible that we’re going to see changes in the way Yellowstone geysers behave.”
Too Early To Tell
But Poland said it’s too early to tell whether or not the June flood made enough of an impact in the annual precipitation to cause changes in Yellowstone’s geyser system.
“There was a lot of rain that fell, but does that qualify this as a wet year?” he said. “And I’m not sure that we know the answer to that yet. There was an epic rain-on-snow event that happened in June, but if July and August were super dry, and I know there hadn’t been a whole lot of snow up until the spring, this qualifies as a dry year despite the flood.”
Earthquakes More Likely To Affect Geyser Activity
Poland said there is significant evidence that even small earthquakes can result in changes in the time between eruption intervals, because the “plumbing” systems are fragile.
“I like to think of them as like plumbing in an old house,” Poland said. “You shake a plumbing system like that, and stuff isn’t going to work. You’re going to spring leaks, things like that.”
He said that when a significant earthquake shakes the area, such as the 7.3 magnitude quake that caused death and destruction in 1959 near Hebgen Lake, thermal features may change temporarily.
“That earthquake was associated with a whole bunch of geyser eruptions in Yellowstone,” Poland said. “At least 289 springs erupted as geysers within a day of the earthquake, and of those, 160 were springs with no previous record of eruption.”
Normal Earthquake Year
Earthquake activity in June was fairly normal, according to Poland, with one magnitude 2.4 event occurring in the northern part of Yellowstone just one day before the flood.
“The University of Utah seismograph stations, which track earthquake activity in Yellowstone through the Yellowstone seismic network, located 149 earthquakes, which is pretty average for the Yellowstone region,” Poland said. “The largest event occurred on June 12, and it was a magnitude 2.4 located just to the south of Mammoth Hot Springs.”
Poland, who is also a research geophysicist with the Cascades Volcano Observatory, said the 2.4 earthquake was part of a swarm of about 67 events that occurred in mid-June and in late June, which Poland said is in no way unusual.
“The other day there was a magnitude 2.5 earthquake south of Jackson, and I started to see things pop up on YouTube,” he said. “There’s dozens of magnitude 2.0 earthquakes every year; there have been thousands in the last few decades.”
“Volcanic Boogeyman”
But Poland would like to see the myth that Yellowstone’s “supervolcano” is ready to erupt at a moment’s notice put to bed once and for all.
“I think over the last 20 years, especially, Yellowstone has become something of a volcanic boogeyman,” Poland said. “There’s an awful lot of outright misinformation on YouTube, and even in tabloids.”
Steamboat Wakes Up
After a long stretch of activity in the last few years, the world’s tallest geyser, Steamboat (located in the Norris Geyser Basin), had significantly slowed its frequency since 2020. But an eruption occurred just prior to June’s flood event, and then just ten days later.
“We had two eruptions during the month of June – one on June 10 and one on June 20,” Poland said.
Poland said that scientists don’t necessarily think that the availability of water is what triggers Steamboat to go into its phases of eruption, but it’s possible that once it is in an active phase, the availability of water modulates how frequently the geyser erupts.
“Steamboat sort of woke up in 2018 and had 32 eruptions that year, and then it had 48 each in 2019 and 2020,” Poland said. “And then in 2021, I think it had maybe 20 eruptions. So a significant drop the previous three years, and that kind of suggested, well, maybe Steamboat is going to go back to sleep.”
Steamboat’s behavior during its active periods is consistent with what scientists have observed about the influence of precipitation on geysers throughout Yellowstone.
“One thing we have noticed about Steamboat over this period, especially in 2018, 2019 and 2020, is the time between eruptions was shorter in the summer than it was in the winter,” Poland said. “So we sort of had maybe an average of 10 days between eruptions in the winter, but it was down to about five days during the summer. And that may be because the groundwater was getting recharged by all of the snowmelt.”
But Poland pointed out that there isn’t enough evidence to theorize that Steamboat’s activity in June was related to the high water event.
“You never really know whether it’s coincidence or whether there’s a causality,” he said, “because we just don’t have enough information to answer that question.”
