Some experts believe that the heavy rainfall which preceded the epidemic that killed as many as 17 million Aztecs in 16th Century Mexico was triggered in part by El Nino…
El Nino is just one of three major weather fluctuations that influence climate in the Americas…
The two other cycles operate in timescales much longer than that of El Nino…
They can be measured as a pattern of sea temperature changes in the two great oceans flanking the Americas…