The Hawaiian–Emperor chain

For 85 million years, molten rock rising from deep within Earth has broken through the Pacific Plate, building volcano after volcano across the ocean floor. As the plate carries each one away from the hotspot, it falls silent, erodes, and sinks beneath the sea, while a new volcano rises in its place. Together, these volcanoes form a 6,000-kilometre trail across the Pacific.

But the hotspot itself has not always stood still. Evidence suggests it migrated substantially during the formation of the older, north–south Emperor Seamounts, which are named for emperors of Japan. This submarine chain, shown in purple, records the combined motion of the Pacific Plate and the hotspot beneath it.

About 47 million years ago, that motion changed dramatically. The bend, shown in orange, marks the transition to the Hawaiian chain, which extends southeast toward the islands and active volcanoes of Hawaiʻi today.