Lava’s magnetic polarity sheds light on origins of giant undersea volcano
DOI: 10.1063/PT.5.029393
Nature : Tamu Massif, in the Pacific Ocean some 1600 km east of Japan, is the largest known volcano on Earth: It rises to 4 km in height, and its base sits 6 km beneath the ocean surface. To try to understand how such a massive structure formed, William Sager of the University of Houston and colleagues used the research vessel Falkor to measure the alternating magnetic polarity of Earth’s magnetic field as recorded in the volcano’s cooled lava. Stripes of magnetic material on either side of Tamu Massif, combined with the lack of magnetic polarity found in the main part of the mountain, indicate that the volcano may have been formed through a complex process involving both plate tectonics and mantle plumes of hot rock that erupted from deep within Earth.