Scientists have discovered a “breathing” magma cap beneath the Yellowstone supervolcano, offering new clues about its eruption potential. This layer, located about 2.6 miles below the surface, acts like a lid on the magma reservoir. While this cap traps significant heat and pressure, it’s not completely sealed. Researchers found it to be porous, allowing for a gradual release of pressure. This natural venting mechanism may explain why Yellowstone hasn’t experienced a major eruption in hundreds of thousands of years.
Using seismic waves the team mapped the upper boundary of the magma system. Their analysis indicates the cap consists of molten minerals and supercritical water bubbles within porous rock. Instead of building up to a critical point, the bubbles appear to be escaping through the cap’s pores, preventing a dangerous pressure surge. Professor Brandon Schmandt of Rice University compares this to “steady breathing,” noting that the volatile content is below levels typically preceding an eruption. The efficient venting of gas through cracks in the cap aligns with Yellowstone’s numerous hydrothermal features that release magmatic gases.
This discovery provides a clearer picture of Yellowstone’s magma system and suggests that the risk of an imminent massive eruption might be lower than previously considered. The “breathing” cap offers a valuable insight into the volcano’s dynamics and highlights the ongoing processes that shape this remarkable geological wonder.