Since scientists can't drill 2,900 km (1,800 miles) to the boundary between Earth's core and deep mantle, they must use information relayed by seismic waves recorded during earthquakes to study this region. In a new study published in the journal JGR Solid Earth, a group of scientists used deep learning to study a large set of a specific type of seismic wave. The analysis revealed six continuous bands of irregularities at the core-mantle boundary (CMB) that had previously appeared only as sparse patches.