Determining the viscosity of bridgmanite, the most abundant mineral in the Earth’s interior – Advances in elucidating mantle dynamics that affect volcanoes and earthquakes –
Summary
A joint research group of Assistant Professor Noriyoshi Tsujino, Associate Professor Daisuke Yamazaki, Professor Takashi Yoshino of the Institute for Planetary Materials, Okayama University, Professor Yu Nishihara of the Geodynamics Research Center, Ehime University, Senior Scientist Yuji Higo and Senior Scientist Yoshinori Tange of the Japan Synchrotron Radiation Research Institute (JASRI), determined the viscosity of polycrystalline bridgmanite, which is the most abundant mineral in the lower mantle in the Earth’s interior, through deformation experiments under high temperature and high pressure conditions. This revealed that the high viscosity of the lower mantle, which had been previously reported through geophysical observations, can be well explained by the viscosity of bridgmanite. Furthermore, it has become possible for the first time to estimate the differential stress and mineral grain size deep in the Earth’s mantle, which had not been able to be sufficiently constrained until now, and it has been shown that most of the lower mantle is convecting independently from the upper mantle. It became clear.
This is expected to be a major constraint when considering models of Earth’s internal evolution. The results of this research will be published in the American scientific journal Science Advances at 3:00 a.m. on Thursday, March 31st (2:00 p.m. on Wednesday, March 30th US time).
For more details, see the Okayama University press release [ JP | EN ].
Reference
Title: Viscosity of bridgmanite determined by in situ stress and strain measurements in uniaxial deformation experiments
Journal: Science Advances
Authors: Noriyoshi Tsujino, Daisuke Yamazaki, Yu Nishihara, Takashi Yoshino, Yuji Higo, Yoshinori Tange
DOI: 10.1126/sciadv.abm1821
