Earthquakes as a potential contributing factor to climatechange at multi-decadal scale

Climate changes at the multi-decadal scale are often associated with multi-decadal phase shifts of the dominant sea surfacetemperature (SST) pattern, such as the Pacific Decadal Oscillation (PDO). The PDO may be associated with the NorthPacific branch of the Thermohaline Circulation (THC). Great earthquakes (M >8), particularly along the route of the THC,might modulate the vertical mixing and bring deep, cold water to surface, contributing to multi-decadal changes in surfacecurrents and the PDO. This may eventually lead to multi-decadal climate changes. We tested this hypothesis for the PacificOcean where great earthquakes have been frequently recorded. We found associations between the PDO and recurrentearthquakes along the route of the deep currents of the THC in the modern period since 1900, and relationships betweenhydroclimate change in Monsoonal Asia and historical earthquakes since 1300. However, it should be noted that thishypothesis is very preliminary and has many gaps that needs further evidences from more observational records andmodeling studies.