Limnic Eruption

[1969912 0]

I recently watched a documentary about an incident near Lake Nyos in Cameroon where 1700 people and a bunch of livestock suddenly died within minutes. Some victims had burns on their skin and the survivors reported sulfur odors. The victims were asphyxiated. The area near the lake is volcanically active, so I immediately thought that a bunch of sulfur dioxide gas was burped up through the lake forming SO2 clouds and aeroslized sulfuric acid. That was wrong. What happened was what's called "Lake Overturn."

In some deep, narrow lakes in tropical areas near active volcanoes, carbon dioxide gas released from magma pockets below the lake dissolves in the water. The water in those lakes is very cold at the bottom and warm at the surface, so little mixing of the two takes place. The CO2 dissolves in the cold water at the bottom, which is at a much higher pressure than the water at the surface. What you have is a layer of water near the bottom that is highly carbonated, and just like a bottle of beer, the only thing keeping the CO2 in solution is the pressure and temperature.

In the Lake Nyos incident, it is postulated that a landslide running into the lake pushed some of the carbonated deep water upwards, where under lower pressure the CO2 came out of solution and formed bubbles. The bubbles, being bouyant, accelerated upwards drawing more of the deep water into their plume. What resulted was an explosion of CO2 gas bubbles at the surface as most of the deep water goth dragged to the surface.

The HUGE cloud of CO2 (heavier than air) then raced downhill, asphyxiating nearly every air-breather in its path. The burns may or may not have been caused by the fact that the CO2 would be VERY cold after coming out of solution and expanding. The sulfur odor?: It turns out that during O2 deprivation events, humans can sense smell incorrectly, often believing that they smell buring matches/gunpowder odors.

They have equipment in place at the lake now that is designed to prevent such a huge accumulation of dissolved CO2.

Fascinating shit. http://en.wikipedia.org/wiki/Limnic_eruption

"Once we got to the point where twenty/something's needed a place on the corner that changed the oil in their cars we were doomed . . ."
-NickDG

[Squeak 17]

Cool

You are not now, nor will you ever be, good enough to not die in this sport (Sparky)
My Life ROCKS!
How's yours doing?