Comment on the paper 'Normal and shear stress acting on arbitrarily oriented faults, earthquake energy, crustal GPE change, and the coefficient of friction' by P. P. Zhu

摘要

In his paper "Normal and shear stress acting on arbitrarily oriented faults, earthquake energy, crustal GPE change, and the coefficient of friction", Zhu (2013) tried to theoretically solve the calculation of the fundamental parameters in seismology. These parameters include the normal and shear stresses acting on arbitrary oriented faults, the earthquake energy, crustal gravitational potential energy(GPE) change (hereon abbreviation or symbol in parenthesis is that used in Zhu's paper), and the coefficient of friction. He especially emphasized the importance of gravitational potential energy (GPE) change, and stated that "many geophysicists accepted the idea of partitioning earthquake energy into radiated seismic energy (ER), friction energy (EF), and rupture energy (ERP) without consideration of crustal gravitational potential energy(GPE) change (e.g. Kanamori 2001; Abercrombie et al.2006; Kanamori and Rivera 2006)," and that "the research on the earthquake energy budget stayed in qualitative analysis for a long time (e.g. Abercrombie et al.2006)." In this short note, I will comment on the fundamental idea presented in Zhu's paper (Zhu 2013) andwill point out that his statement is incorrect.