The last time I wrote about the Yellowstone supervolcano, an earthquake about 100 miles from the famous caldera renewed some concerns about a potential eruption.
Now speculation has started again after Yellowstone’s Echinus Geyser, the largest acidic geyser on Earth, has erupted again for the first time since 2020.
Located in the Back Basin of the Norris Geyser Basin, the geyser unexpectedly erupted on Feb. 7 after nearly six years of dormancy, marking its first eruption since December 2020, with subsequent bursts on Feb. 9, 12 and 15.The activity shifted into high gear on Feb. 16, with eruptions occurring every two to five hours, according to the U.S. Geological Survey (USGS).The agency noted the rarity of acid geysers, as the acidic water can break down the rock that makes up a geyser’s plumbing system.“At Echinus Geyser, however, the composition is due to mixing between acidic gases and neutral waters, and the acidity is not sufficient to eat away at the rock,” the USGS said.
The eruptions tend to be cyclic, and there are signs the geyser is already slowing down.
The eruptions have been lasting two to three minutes and reaching about 20 to 30 feet in height. After each eruption, the water level decreases significantly and does not return to normal for about an hour. The overall pattern resembles activity seen in late 2017.People can track Echinus Geyser’s activity through temperature graphs on the Yellowstone Volcano Observatory website. Spikes that reach about 70 degrees Celsius, or 158 degrees Fahrenheit, indicate eruptions, while spikes reaching 40 to 50 degrees Celsius, or 104 to 122 degrees Fahrenheit, indicate surges.Whether the eruptions will continue into the summertime remains uncertain. The geyser has a tendency to become active for a month or two before going quiet again, and there were no eruptions during the last few days of February, suggesting it may already have calmed.
Presently, the United States Geological Survey (USGS) assures everyone that the current level of seismic activity is normal.
During February 2026, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, located 74 earthquakes in the Yellowstone National Park region. The largest event of the month was a microearthquake of magnitude 2.4 located about 12 miles north of Pahaska Tepee, Wyoming, on February 24 at 1:11 a.m. MST.February seismicity in Yellowstone was marked by a swarm of 12 earthquakes that occurred approximately 6 miles north of West Yellowstone, Montana, during February 7–8. The largest earthquake in the sequence was a magnitude 2.2 event on February 7 at 1:07 a.m. MST.Earthquake activity in Yellowstone is at background levels.
However, given the kind of year 2026 has already been, a Yellowstone eruption would be on brand.
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