An empirical correlation between the occurrence of earthquakes and typhoons in Taiwan: a statistical multivariate approach

This study looks at 102 typhoons that passed nearby or traversed Taiwan from 1995 to 2011 and their potential association with ordinary earthquakes. The study found an overall association of 63.75 %. Interestingly, prior to the September 21, 1999, M (w) = 7.6 Chi-Chi earthquake, only 4 of 24 typhoons (16.67 %) were potentially associated with the earthquakes. This figure increased substantially after the Chi-Chi earthquake to 78 typhoons being possibly associated with earthquakes (78.21 %). From the results of the chi-square test, both correlations between the typhoons and their possible triggered earthquakes before and after Chi-Chi earthquake have significant difference. The results are discussed in terms of changes in crustal conditions after the Chi-Chi earthquake and potential mechanisms, for example, heavy rainfall and atmospheric pressure causing the ordinary earthquakes. The atmospheric pressure effect predominates over the rainfall effect during the typhoon time period by statistical multivariate approach. However, to test rainfall effect is a non-neglected mechanism; seven small earthquakes without typhoon occurring near a region experiencing heavy rainfall and earthquake activity related to accumulated rainfall values from January 1995 to July 2012 are examined.