One highly debated topic about Earth's interior is mantle plumes. These are theorized to be rising magma, which is responsible for the hotspots in the world, like Hawaii. Originally the theory was that mantle plumes rose up in a direct path, but now there is evidence that the plumes may deflect by small degrees as they rise.[7] It was also found that the proposed hotspot underneath Yellowstone may not be related to a rising mantle plume.