Hotspot Volcanoes

Not all volcanoes form at plate boundaries. Hotspots are plumes of unusually hot mantle material that rise from deep within the Earth, melting through the crust like a blowtorch. The Hawaiian Islands formed as the Pacific Plate drifted over a stationary hotspot, creating a chain of volcanic islands stretching over 2,400 kilometers.

The oldest Hawaiian island (Kauai, 5.1 million years old) is at the northwest end of the chain, while the youngest (Hawaii's Big Island) sits directly over the hotspot today. A new island, Kamaehuakanaloa (formerly Loihi), is already forming underwater southeast of Hawaii, about 975 meters below the surface.