Two SMU geology researchers have discovered a symmetrical distribution for the "hot spots" on the Earth's surface.

Scientists have located 47 places on the Earth's surface where volcanic activity unrelated to plate tectonics occurs, including Hawaii, Yellowstone, Iceland, and the Galapagos Islands. Hot spots mark the sites of ancient "mantle plumes" where huge amounts of volcanic material rose from deep within the Earth. Today, residual material representing the tails of these mantle plumes still comes up at these hot spots.

Although previous studies have reported that hot spots tend to occur in broad clusters, an orderly arrangement in their distribution had not been recognized. SMU geologists Rebecca Ghent and Douglas Oliver studied the location of major hot spots and determined that a disproportionate number occur at latitudes between 20 and 30 degrees north and south of the equator. Their observation became much more significant when the hot spots were weighted according to the amount of volcanic material that they produced. Statistical analysis shows that the likelihood of this distribution arising by chance is less than one percent.

"This hints that there is something going on deep within the Earth that hasn't been suspected before," Oliver says.

Oliver and Ghent are investigating processes within the Earth that may be responsible for this phenomena. Oliver presented their research at the 112th annual meeting of the Geological Society of America in November.

For more information: Doug Oliver
oliver@mail.smu.edu