Hawaiian mantle plume heats up

New research led by Michael Garcia at the University of Hawaiʻi at Mānoa reveals that the Hawaiian mantle plume has increased in temperature by about 250°C over the past 47 million years, challenging the long-held belief that hotspots cool over time. The study, published in Earth and Planetary Science Letters, used a novel geothermometer on olivine basalts from 16 volcanoes along the Hawaiian Ridge. Two heat surges were identified: one 14-20 million years ago forming Gardner Pinnacles, the largest shield volcano in 60 million years, and another 0-6 million years ago forming the Main Hawaiian Islands. The findings suggest that dense, hot material in the lowermost mantle may be drifting beneath the Pacific plate, driving the temperature increase.