Science Forums 2

[Michaelangelica]

i was promted to start this thread when i read a letter to the Editor in the local paer insting that methane was NOT agreen house gas.

The Methane Clathrates were a nasty suprise.

The seafloor off Santa Barbara just burped up a huge eruption of methane - and scientists caught it on video. Now, at about 5,000 cubic feet at the surface, this methane cloud was huge by people-watching-with-videocameras standards. That’s not to say massive by vast-limitless-ocean standards. But still, it gave the scientists a chance to do some number-crunching on an imaginary massive eruption of methane.

And why are the scientists stretching their imaginations in this way, you might ask? Well, it turns out that there are actually massive (not just huge) deposits of methane on the ocean floor (and in Arctic permafrost, too, but that’s another story). The ocean deposits are quiescent at the moment, frozen into sort of waterlogged crystals called methane hydrates, a.k.a. clathrates (here’s a bit more blogging on clathrates).

Pulling the Clathrate Trigger surf.bird.scribble.

Gas Hydrates (Clathrate Hydrates)

Clathrate hydrates constitute a class of solids in which the guest molecules occupy, fully or partially, cages in host structures made up of H-bonded water molecules. The usually unstable empty clathrate is stabilised by inclusion of the guest species. In case of guest molecules which are gaseous at ambient conditions the resulting clathrate hydrate is often called a gas hydrate. These compounds are interesting for several reasons: much could be learned about water-water interactions in these topologically rather complex systems, especially if one could follow the pressure dependency of the host structure over a wide pressure range. Likewise, much could be learned about the guest-host interactions in a wide range of guest species from noble gas atoms to large (and polar) organic molecules. Clathrates are believed to occur in large quantities on some outer planets binding gas at fairly high temperatures, which is an interesting issue for planetologists.

Werner F. Kuhs: Clathrate Hydrates