The Yellowstone National Park in the USA with its geysers and hot springs is a great attraction for tourists.
The Yellowstone National Park in the USA with its geysers and hot springs is a great attraction for tourists. However, especially in times of little news, the media often focusses on the Yellowstone Supervolcano, which last erupted about 630,000 years ago. Inevitably, then the question of the underlying geological structures will be posed. A recent study by Bernhard Steinberger of the German GeoForschungsZentrum and colleagues in the USA helps to better understand the processes in the Earth's interior. The paper will soon appear in the journal "Geochemistry, Geo-physics, Geosystems" published by the American Geophysical Union. It is based on modelling the Earth's mantle.
According to the model, beneath the Yellowstone volcano lies a so-called mantle plume: a chimney-like structure that reaches thousands of kilometres deep to the border of the Earth's core and mantle. The origin of the plume lies under the "Baja California", more than a thousand kilometers southwest of the national park. Evaluations of earthquake waves had already suggested something like this, but the idea of such a "mantle plume" did not fit in with the movement of the Earth's lithospheric plates.
It is clear that Yellowstone is a so-called intraplate volcano. Most volcanoes in the world are located at the borders of continental plates, either where material from the Earth's interior rises, as along the mid-Atlantic ridge, or where one continental plate submerges under the other and melts, as is the case along the South American west coast. In contrast to plate boundary volcanism, intraplate volcanism goes back to "hotspots" under the Earth's crust. This can be imagined as a welding torch that melts the lithosphere from below - where a hole is virtually burned through, a volcano grows. This is how Hawaii, for example, came into being.
Read More at: GFZ Geoforschungszentrum Potsdam, Helmholtz Centre
The model results show high similarity with interpretations from seismic waves. The circles mark the old Yellowstone crater remnants (calderas) indicating that the continental crust moved westwards. The mantle plume below the hot spot is tilted with its origin below Baja California. (CCBY 3.0: Steinberger/GFZ) (Photo Credit: Steinberger et al.)
