Studying the dynamics of volcanoes and their origins beneath the Earth’s crust is important for understanding the Earth’s mantle and its geochemical processes.
One proposed mantle mystery that has been the subject of debate is the existence of deep mantle plumes that could explain the the hotspot beneath the famed Yellowstone Caldera.
Researchers from the University of Texas may have finally proven that mantle plumes exist and that the one beneath Yellowstone reaches as far as Mexico.
A magma plume is a theorized mushroom-shaped thermal anomaly with a thin trail of magma rooted in the boundary between the Earth’s core and mantle.
The volatile conditions that occur at the core-mantle boundary (CMB) are the supposed cause of mantle plumes, but their existence is not widely accepted.
Many have theorized that a mantle plume lies beneath Yellowstone’s supervolcano which could explain the array of geothermal features and surface activity around Yellowstone National Park.
The researchers analyzed data from the USArray network which records and tracks seismic activity around North America.
By focusing specifically on the seismic activity around Yellowstone and using new imaging techniques, the study gives compelling evidence for a plume of magma underneath Yellowstone.
The researchers discovered a 45 by 34 mile channel below the earth’s surface where seismic waves are slower.
If this were a mantle plume, according to the study’s calculations the mantle would be hotter than anything around it and could reach temperatures of 800 degrees Celsius.
The researchers conclude in their paper that this plume is the likely “driving source” behind the volcanic activity around Yellowstone.
“Our results strongly support a deep origin for the Yellowstone hotspot, and also provide evidence for the existence of thin thermal mantle plumes that are currently beyond the resolution of global tomography models,” write the researchers.
—
By Kay Vandette, Earth.com Staff Writer