A recent study by Jonathan Wolf and Maureen Long uses earthquake waves and high-performance computing to analyze material flow deep in Earth's mantle, near the outer core boundary, around 3,000 km below the surface. Researchers found ancient slabs drive flow beneath the northeastern Pacific and detected upward flow at the Yellowstone plume. They also discovered that mysterious mantle features called ultralow velocity zones (ULVZs) can be moved by mantle flow, especially under the Himalayas. These findings link deep mantle dynamics to surface events like plate tectonics, volcanism, and Earth's magnetic field.