Comment on “Coupling semantics and science in earthquake research”



Kelin Wang and Timothy Dixon (Eos, 85(18), 4 May 2004, p. 180) thoughtfully advocate paying close attention to semantics in descriptions of fault zone properties and kinematics, an increasingly important issue given the distinct usages of terms such as “coupling” by separate disciplines involved in the multidisciplinary study of earthquake faulting. We are in full accord with their advocacy of unambiguous language, such as the description of a nonsliding fault segment as being “not slipping” rather than “strongly coupled” in the absence of any information about the frictional or stress state of that segment. While several of Wang and Dixon's recommended “simple expressions” have clear merits, we feel that their advocacy of “locked” to equate to “not slipping” is not an improvement, and that their accompanying illustration of dislocation models of subduction zone megathrusts is potentially misleading.