JoNova

A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).


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Massive Eltanin Meteor 2.5 million years ago set off mass tsunami, changed the climate?

From the file of “Things that would really be catastrophic”. Did a meteor have a role in a major shift in Earth’s Climate?

The start of the Quaternary period (2.588 million years ago, where the Pliocene became Pleistocene) coincides with evidence of a mega tsunami in the South Pacific.

The Eltanin Meteor fell into the South Pacific 2.5 million years ago setting off a (likely) tsunami that was hundreds of meters high and theoretically pushed mass material into the atmosphere which may have contributed to the cooling the globe had already started on. This meteor was hard to detect because it hit the ocean rather than the land. But researchers have pieced together evidence of the mass tsunami on continents around the pacific rim.

Figure 1. Possible effects of the Eltanin megatsunami. (A) Composite model of wave amplitudes for the South Pacific [modified after Ward and Asphaug (2002) but with a greater decay rate of wave amplitude away from the impact point; this produces lower wave amplitudes on affected coasts, more in line with recent findings but not as low as those proposed by Shuvalov and Trubetskaya (2007)]: ANT, Antarctica; AU, Australia; NZ, New Zealand; SA, South America. (B) […]

The deep oceans drive the atmosphere

Ever wondered how the whole planet could suddenly “get warmer” during an El Nino, and then suddenly cool again? William Kininmonth has the answer. As I read his words I’m picturing a major pool of stored “coldness” (bear with me, I know cold is just a lack of heat) which is periodically unleashed on the surface temperatures. The vast deep ocean abyss is filled with salty and near freezing water. In years where this colder pool is kept in place we have El Ninos, and on years when the colder water rises and mixes up near the surface we have La Ninas. The satellites recording temperatures at the surface of the ocean are picking up the warmth (or lack of) on this top-most layer. That’s why it can be bitterly cold for land thermometers but at the same time the satellites are recording a higher world average temperature, due to the massive area of the Pacific.

In other words, just as you’d expect, the actual temperature of the whole planetary mass is not rising and falling within months, instead, at times the oceans swallow the heat on the surface and give up some “coldness”. At other times, the cold […]