A recent study of earthquake data in the Pacific area could have seismic implications for the long-held assumption about how the Hawaiian Islands were formed.

Although never conclusively proven, it had been widely accepted that the islands were formed by a single plume of hot rock originating from the earth’s core. The theory held that movement of the earth’s crust via plate tectonics caused the formation of mounts, mountains and eventually islands.

However, in a study just published in the journal Science, a team of geophysicists led by Qin Cao of MIT report that they have discovered an 800-mile-wide area of hot rock in the Hawaiian region and that it is hundreds of miles from the nearest Hawaiian island. This would appear to disprove the assumption that the so-called hot spot that formed the island chain was currently located beneath the island of Hawaii, which is still being formed by active volcanic eruptions.

The study’s authors are reluctant to discount the hot-spot theory entirely. They say it is possible that a narrow plume of hot rock may be branching off the larger mass, pooling between the upper and lower mantle before snaking its way below the Hawaiian archipelago and feeding the ongoing Kilauea eruptions.