Xiang GAO
Institute: Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences
Title: Specially-appointed Professor
Country: China
Period: 2016/4/1 - 2016/9/30
Theme: Role of temperature and fluids on subduction zone earthquakes
Host: Makoto YAMANO
Introduction: My research focuses on geodynamics of subduction zones and related earthquake hazards. I'm particularly interested in exploring physics of subduction zone earthquakes, addressing questions like how fault strength affects subduction zone large earthquakes, how fault zone rheology controls ETS and related phenomena, and how fluids circulation in oceanic crust affects subduction fault temperature and earthquake generation.
I collaborated closely with Dr. Kelin Wang on strength of subduction faults. We numerically simulated frictional heating from various subduction megathrusts and used heat flow measurements as constraints. We found that megathrusts that produce great earthquakes generate less frictional heat than those that creep. The lower frictional heating indicates weaker faults. We explained that megathrust strength and seismogenic behavior are controlled by the ruggedness of the subducting seafloor, with smoother seafloor leading to weaker faults and larger earthquakes. Now we are working on the relationship between the seismogenic zone and the ETS zone by examining fault zone rheology. We seek to explain the observed spatial gap between these two zones and the occurrence of ETS-type phenomena around mantle wedge corner from abundant to absent among the various subduction zones globally.
During my stay at ERI, I will work with Dr. Makoto Yamano on effect of fluids circulation in oceanic crust on subduction zone earthquakes. Recently, along-strike heat flow variations were observed at the Nankai Trough by Dr. Yamano and other colleagues and were attributed to different patterns of fluids circulation. We will investigate how these along-strike variations of fluid circulation patterns cause heterogeneity in the subduction fault temperature and strength and then affect fault slip mode.

It is a great pleasure to be here at ERI. I will be very happy if you stop by and have a chat. My ERI office is 612 in Building#1.
Fiscal Year: 2016