Yellowstone National Park is known for its dramatic geysers and bubbling hot springs, but scientists have recently uncovered a hidden geologic structure that could be the key to keeping its massive volcanic system calm. A team of researchers discovered a porous magma cap about 2.4 miles below the surface, composed of a mixture of molten rock, supercritical water, and gas-filled openings.
The discovery was made using advanced seismic imaging techniques, including a custom wave-equation imaging method developed by researcher Chenlong Duan to clarify scattered signals. The team also used a 53,000-pound vibroseis truck to send low-frequency vibrations into the earth, which helped pinpoint unusual features at depths that few had ever probed before.
According to Brandon Schmandt, one of the researchers, “The cap appears to be a mix of molten silicate materials, supercritical water, and rock with openings that allow gas to flow. This combination forms a barrier that traps deep heat yet still permits venting of volatiles.”
Volatiles like water vapor and carbon dioxide play a crucial role in determining whether magma stays underground or forces an eruption. However, the team’s findings suggest that Yellowstone’s volcanic system is steadily relieving pressure through cracks and channels, allowing bubbles to emerge and vent rather than staying trapped.
The study provides valuable insights into the conditions underground and highlights the importance of monitoring volcanic hazards. By tracking changes in the cap’s melt or gas content, volcano experts can better understand the risk level and make informed predictions about future eruptions.
The discovery also supports broader research on carbon capture and geothermal exploration, with Yellowstone offering a real-world lab to test new ideas about fluid movement in the crust. As researchers continue to study the park’s volcanic system, they aim to develop more advanced seismic methods and better data coverage to gain clearer pictures of structures that help contain magma in other large volcanic areas.
Source: https://www.earth.com/news/magma-layer-keeps-the-yellowstone-supervolcano-dormant