New research shows the Hawaiian mantle plume has gotten hotter by about 250°C (480°F) over the past 47 million years.
New research shows the Hawaiian mantle plume has gotten hotter by about 250°C (480°F) over the past 47 million years. Led by Earth scientists at the University of Hawaiʻi at Mānoa, the study published in Earth and Planetary Science Letters, reverses the long-held idea that hotspots start out very hot and progressively cool with time. Researchers also found that heat surges produced the two largest volcanoes along the Northwestern and Main Hawaiian Island chain.
The Hawaiian Ridge consists of 65 volcanoes spread over 3,500 km (2,179 miles) that were formed during the past 47 million years as the Pacific plate slowly moved over the Hawaiian hotspot, where a plume of molten material flows out of Earth’s crust. A team of researchers, led by Michael Garcia, Emeritus Professor of Earth Sciences in the UH Mānoa School of Ocean and Earth Science and Technology, set out to evaluate hypotheses that might explain the 100-fold fluctuation in lava volume along this ridge. By examining olivine basalts from 16 volcanoes, the researchers assessed four testable causes, including changes in lithosphere thickness, magma source composition, rate of the Pacific plate movement and plume temperature.
“It was a major surprise to find such a strong, direct correlation between mantle temperatures and volcano size,” said Garcia. “Other potential explanations simply failed to explain the data.”
Read More: University of Hawaii
Photo Credit: AStoKo via Pixabay
