Tuesday, October 09, 2007
Mega-Disasters: Methane Explosion (History Channel)
On Tuesday October 9, 2007 The History Channel presented “Mega-Disasters: Methane Explosion.” (or "Methane Eruption"). The one-hour show documented a theory by Northwestern University professor Gergory Ryskin to the effect that at a few times in geologic history (particularly 250 million years ago with the Permian Mass Extinction) methane (C-H4) may have bubbled out of the oceans from some stagnant areas and then been ignited by lightning, producing a global firestorm. In fact, the bubbling could cause huge tsunamis comparable to those from the largest volcanic landslides.
Other scientists question the theory. It takes a huge amount of methane at once to produce an explosive mixture, which can happen only over a large area of stagnant ocean, probably filled with frozen methane hydrates at the bottom. Methane hydrates are a form of ice with embedded methane molecules surrounded by water in odd ring structures. It forms only at very great pressure and low temperature at great depths. Methane hydrate crystals will burn despite the water content (and so would vapor with a high enough concentration of methane); it seems to be a real covalent compound and not just a colloid. That could make an interesting high school chemistry laboratory experiment (under supervision of course).
There was a geyser of carbon dioxide at Lake Nyos in Cameroon, released by volcanism, with the carbon dioxide sliding down and killing villagers and animals.
Release of methane from hydrates could cause extreme global warming. This may have happened 55 million years ago with the Paleocene Eocene Thermal Maximum.
The History Channel also had a show on Jupiter, whose weather is an extreme blowup of earth’s, as well as a detailed discussion of Europa and the possibility of life under its global icecap