A report at the Seismological Society of America’s annual meeting shows that the volcano under Yellowstone National Park is bigger and much better connected than previous scientific reports.

“The magma reservoir is at least 50 percent larger than previously imagined,” Jamie Farrell of the University of Utah stated.

Farrell studied a series of earthquakes to measure the magma chamber based on sound wave speed. The speed of sound waves change when they move through molten rock versus solid rock.

The sound wave study produced a picture of the underground magma chamber in the shape of a “mutant banana” with a ball at the northeast corner of the Park and the reach angling southwest. The chamber is 37 miles long and at some points only 3 miles deep.

All previous research led scientists to believe that the magma was in separate blobs and not one pocket. The scientists believe that additional magma exists deeper under the park than could be found in the sound wave study.