Now, a new study has found evidence of a “ghost plume”—a mantle plume that shows no sign of volcanic activity on the surface—under eastern Oman. Understanding these ghost plumes, and especially developing ways to find more of them, will help geologists better understand how much heat is escaping the core-mantle boundary. This means that temperatures were much higher in this region, indicating the presence of a mantle plume. “The more we gathered evidence, the more we were convinced that it is a plume,” Pilia told New Scientist. Not only could that change Earth’s geologic history, but mantle plumes provide many real-world benefits.