Craig R. Bina 氏 (Northwestern University)

「Phase transitions in subduction zones:
Stresses, seismicity, stagnation, and structure」　

2006年5月10日

　Mineralogical phase relations in subducting lithosphere
differ from equilibrium phase relations in the surrounding
mantle, due to low temperatures in the slab.
These perturbations juxtapose high-density and low-density
material, yielding petrological buoyancy anomalies.
The resulting buoyancy forces contribute to the stress fields
in subducting slabs, as can be seen in regional and global
patterns of seismic moment release.
　These buoyancy forces should also affect the plate velocities
of subducting plates, and they may also contribute to deflection
or stagnation of subducting slabs within the transition zone.
In addition to buoyancy anomalies, such thermal perturbation
of phase relations also contributes to complexity in seismic
velocity structures.