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 volcano away from the Hawaii hotspot, the volcano falls silent, erodes, and slowly 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 formation of the older, north–south Emperor Seamounts, named for the 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 red marks the transition to the Hawaiian chain, which extends southeast toward the islands and active volcanoes of Hawaiʻi today.

Every feature on this map was built by this same evolving volcanic system, from the oldest drowned seamounts near the Kuril–Kamchatka Trench off Russia to the volcanoes still growing around Hawaiʻi.