Closer to Earth: A new technique for examining ultralow velocity zones at Earth's core-mantle boundary

The core-mantle boundary (CMB) is crucial for the Earth's magnetic field and rotation. It is known that this boundary harbors complex structures, including ultralow velocity zones (ULVZs), characterized by significantly slowed seismic wave velocities. The origin and structure of these zones are key to unraveling and understanding some secrets in related fields, especially the Earth's science.