Tokyo Tech News

Unprecedented insights into the mysteries of materials and dynam


Published: May 31, 2011

The details of research

Since it is not possible to access and bring up materials from depths greater than 200 km, the deep Earth is still largely uncertain.

Here, Kei Hirose describes the development of the experimental device called laser-heated diamond-anvil cell using a pair of single crystal diamonds, which generates the high-pressure and -temperature conditions that exist inside the Earth.

Hirose and colleagues recently succeeded in producing more than 364 gigapascals and 5000 degrees Celsius inside this device—conditions corresponding to those expected at the center of the Earth.

Recently, such apparatus enabled the important discovery of the so-called ‘post-perovskite’—a new mineral—above 120 gigapascals at the Earth’s lowermost mantle. “Our discovery is the first evidence for materials constituting this enigmatic part of the Earth.” says Hirose. “Its existence enhances the solid-state convection in the mantle and resulting volcanic activity at the surface.”

The discovery of post-perovskite is a tremendous advance in the understanding of the Earth’s mantle. In the future Hirose and his colleagues plan to investigate properties of the lumps of iron constituting the Earth’s core below the mantle.

Kei Hirose

Kei Hirose
Earth-Life Science Institute