Volume 8, Issue 4
Seismic tomographic studies have determined three-dimensional (3D) velocity structures, in detail, of the crust and the upper mantle of the Earth. Yet, simple two-dimensional (2D) sections have generally been used to present 3D tomographic results. Here we show 3D views and animations of the Earth's structure that are made as easy as 2D sections by using Mathematica. As an example, low-velocity zones in the upper mantle are shown in three dimensions together with major volcanoes, mid-crustal reflectors, earthquake hypocenters, the Moho discontinuity, and the upper plane of the subducted slab that are observed in northeastern Japan. Low velocities in volcanic areas generally correspond to high temperature and indicate possible presence of magma. The 3D animations enable us to investigate the special correlation between low-velocity zones, volcanoes, reflectors, earthquakes, and the slab, and thus enable us to study magma ascent pathways in detail.
(If you don't have a copy of Mathematica, you can view notebooks with Mathematica Player.)
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