Anomalous tremor before 2008 Ms8. 0 Wenchuan earthquake: a review

:In this paper we give a review of several previously published papers on anomalous tremors observed before the 2008 Ms8. 0 Wenchuan earthquake. Based on the observed time and frequency shifts between coastal and inland stations, we discussed some methods to distinguish different kinds of microseisms, and speculated that a pre-earthquake typhoon might have caused a “mainland-originated microseism” which in turn triggered the earthquake.