The supervolcano in Yellowstone national park was in the news this week, with new research based on ‘geoelectric’ measurements indicating the plume of partially molten rock is much larger than previously thought. An earlier study based on seismic waves showed molten rock extending 150 miles west north-west, reaching at least 410 miles deep. The new work from Geophysicists at the University of Utah puts the conductive part of the plume at 400 miles, aligned in an east west direction, however the imaging was only able to see 200 miles deep.
The difference in size is explained by the use of two different imaging techniques. As principle author, Professor Michael Zhdanov puts it:
It’s like comparing ultrasound and MRI in the human body; they are different imaging technologies.
The press release includes two images. In the first, yellow and red indicate higher conductivity:
This other compares the map from the new study (left), with a conventional seismic image: