The famous Steamboat Geyser in Yellowstone National Park has begun erupting far more frequently than it has for years, but don't panic, the attraction’s resident geologists have been quick to reassure the public that the activity does not necessarily reflect any sort of impending disaster.
According to the park’s network of monitoring sensors, Steamboat – the largest active geyser in the world – has belched out three bursts of water and steam in the past six weeks, ending a period of dormancy stretching back to 2014. The latest of the three events occurred on Friday.
During the geyser's more spectacular eruptions, superheated water jets up to 91 meters (300 feet) in the air for up to 40 minutes, followed by a plume of steam that continues for several days.
None of the 2018 eruptions have been quite that massive, though the two most recent ones still discharged approximately 10 times the amount of water as an Old Faithful eruption.
And unlike Old Faithful, most geysers don’t stick to a predictable schedule. Michael Poland, the lead scientists at the US Geological Survey Yellowstone Volcano Observatory told IFLScience that it is not unusual for geysers to switch from cycles of few to no eruptions for decades on end to phases of ramped up activity.
Case in point: No eruptions were noted at Steamboat between 1911 and 1961, yet 1982-1984 and 2013-2014 were marked with regular events. Then, in 2003, the Norris Basin showed a surge of exciting activity. Several of the area’s geysers sputtered with renewed vigor, ground temperatures soared, and a cluster of vents that opened up and spewed steam and burning rock fragments. This period of “thermal disturbance” smothered the surrounding vegetation and forced rangers to close the area to visitors.
The same year, Steamboat erupted three times.
“It's unclear why this happened, but the Norris area is known for having thermal changes over time,” said Poland. “Steamboat’s eruption pattern is quite random, so it's entirely possible that the eruptions had nothing to do with the disturbance.”
As of now, Poland and his colleagues are unsure whether Steamboat’s eruptions represent a fresh flurry of geothermal changes under Norris basin, or if the geyser is simply venting several years’ worth of pent-up pressure.
The one thing that Yellowstone geologists can be quite sure of is a lack of imminent danger from the Yellowstone supervolcano, which last erupted about 70,000 years ago. Currently, the magma driving geothermal activity at Norris basin is 4.8-9.7 kilometers (3-6 miles) deep, and any tectonic activity moving it closer to the surface would be readily detected on seismographs. Plus, if magma were rising, the water accumulated above would quickly boil away, meaning that as long as the geysers are flowing, lava won't be doing the same any time soon.