The El Nino phenomena is the result of the east-to-west flowing equatorial planetary winds along with the accompanying ocean currents. These equatorial ocean currents impinge the Asian landmass and there accumulate and actually build-up. The Asian landmass, coupled with the Indonesian Island Arc to the south, form an entrapping cul-de-dac to approaching waters from the west. The periodic lessening of equatorial winds would unleash the built-up waters pressed against Asia. The short-lived two to three year long eastward flow would lap against the western shores of the Americas, with particular intensity along the Peruvian continental margin. The closing of the Isthmus of Panama over the past several million years strengthens the El Nino effect. Once there, the well-warmed equator abiding waters promote great evaporation and result in devastating torrential rains upon a normally arid land. Rapid and destructive erosion occurs from high Andean crests across the coastal plain. This is the standard description of the El Nino associated with the Holocene, the present and continuing highstands of sealevel.

El Nino conditions during the multiple Ice Ages and lower sealevels appear to have been more energetic than those characteristic of Holocene-type highstands. Such an alternating climatic paradigm seems to have lasted for the past one to two million years. With lower sealevels, the porous nature of the Indonesian Island Arc is reduced and the entrapping aspects are increased. Paleontological evidence reveals that the tropical conditions of the equator persisted through the lowstand Ice Ages. With greater thermal gradient along a latitudinal traverse, the meridianal gradient should also be accelerated, creating stronger equatorial currents. Stronger east-to-west flow and greater water masses entrapped against Asia make more powerful El Nino events.

The growth of the Indonesian Island Arc continues to the present. The generative mechanism is subduction of the Indian Plate. New Guinea is a resultant of that subduction along with the northernmost extent of the Australian landmass. This subduction phrase, begining 20 to 30 million years (my) ago, interruted the paleo-globial ocean current structure of the Tethys Sea.

A working hypothesis is that the El Nino phenomena has been active for the past 20 to 25 my with an ever-strengthening east-to-west current structure.