In June of this year, I got to tour Yellowstone National Park, specifically the Biscuit Basin. I got to tour all around it, seeing the boiling water simmer at the surface and the water flowing all throughout the system. I even got to see some steam release out of one of the vents at the Biscuit Basin.
I also got to explore Old Faithful and Mammoth Hot Springs. I could also feel the intense heat and the smell of sulfurous, rotten egg-like smell release through the vents.
Mammoth Hot Springs.
I would never expect something so strange to occur just a month later. Or was it so strange?
On July 23, 2024, a sudden hydrothermal explosion rocked the Biscuit Basin in Yellowstone National Park, ejecting a significant amount of rock and debris from beneath the surface. This unexpected event temporarily blocked pathways used by tourists to explore the basin. As news spread, many people jumped to the conclusion that this incident was related to volcanic activity, fearing an imminent eruption of Yellowstone’s famous supervolcano. While it’s true that this type of event is somewhat linked to volcanic forces, it doesn’t signal that a massive eruption is on the horizon. In fact, this explosion was a hydrothermal eruption, which is a far less common and less dangerous form of nonvolcanic activity.
Post-explosion Biscuit Basin.
Hydrothermal Explosions
Hydrothermal eruptions occur when trapped steam, water, and rocks are violently expelled due to a sudden drop in pressure. Unlike volcanic eruptions, which are driven by molten magma, these explosions are triggered by the pressure buildup in underground water systems. In this case, the explosion was likely caused by the accumulation of sinter, a mineral deposit formed from geothermal water. Over time, sinter can clog the vents in hydrothermal structures, leading to a buildup of pressure that, when released, results in an explosion. While this 2024 event was significant—being the largest hydrothermal eruption since 1986—it doesn’t indicate that volcanic activity is imminent. The explosion was typical of the natural processes at work in Yellowstone’s massive caldera, where such eruptions occur every few years at varying levels of intensity. Despite the dramatic nature of this incident, Yellowstone’s volcano remains stable, with its magma chamber containing an insufficient amount of molten material to trigger a large-scale volcanic eruption. As a result, the alert level for Yellowstone remains at green, indicating normal activity.
A hydrothermal eruption at Wall Pool.
Hydrothermal eruptions, though less understood by the public, are not uncommon in geothermal areas like Yellowstone. They are caused by a combination of geothermal pressure and geological buildup, which can result in steam explosions rather than eruptions of lava. Because Yellowstone is a large caldera, these eruptions can happen sporadically and are part of the natural cycle of the park's geothermal features. The build-up of sinter, in particular, plays a crucial role in blocking vents, leading to explosive discharges when pressure from the boiling water and steam below the surface becomes too great. Such explosions, however, pose little risk in terms of larger volcanic activity and are simply a dramatic display of Yellowstone's geothermal power.
Yellowstone is Incapable of Producing an Eruption at the Moment
It’s important to note that while Yellowstone is home to a supervolcano, its magma chamber currently lacks the necessary amount of melted rock to create a large-scale volcanic eruption. The overall structure of the volcano is stable, and scientists continuously monitor the region for signs of any significant changes. This 2024 explosion, like many before it, is not a precursor to a volcanic eruption. The geothermal and volcanic systems in Yellowstone are well studied, and this hydrothermal event falls within the range of expected, though infrequent, occurrences. While this event caught the attention of many and caused a surge of online speculation, there are no indications that a volcanic eruption is imminent, and park officials have assured the public that Yellowstone remains safe for visitors.
To the right of this picture would be Black Diamond Pool and Black Opal Pool. This is Sapphire Pool.
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