Volcano is Acting Up #3: Pele is Smoking!

[Les C]

So I did a little googling and found that what I read was incorrect, or I interpreted it incorrectly. SO2 IS a component of vog, so is SO3, and the rest are referred to as other volcanic particulates. The other parts about the smell, or lack thereof, and the acidity seem to be correct.

http://pubs.usgs.gov/fs/fs169-97/

http://tinyurl.com/3vfj48

edit: changed the initial posting of the Science Direct URL to a TinyURL. I hate it when long URLs make you have to scroll left and right on a web page.

[missydog1]

hi Les, yes everything you said before seemed correct according to my reading (I've done a fair amount of that), with the one exception that you thought S02 might be more dangerous than hydrogen sulfide. H2S is the more deadly. A few breaths of it at high levels can cause death.

http://www.atsdr.cdc.gov/tfacts114.html#bookmark05

[ArtM]

Sulfur dioxide is decidedly not odorless. You can prove it to yourself because it is what you get when you burn pure sulfur, that is, the "burning sulfur smell" [xx(] The material safety data sheet describes it thus:

"Colorless gas with a highly irritating, pungent odor."

ArtM

(Now posting as "Da Kine"! [8D])

[missydog1]

right, Art, but a lot of people think they can tell if sulfur dioxide is high by the smell, and the smell they're checking for is the rotten egg smell much of the time. Civil Defense is trying to get people to understand that S02 safety levels can't be determined by an individual call, but rather, people need to pay attention to the monitored levels and take the issue seriously when there's an advisory or alert instead of blowing it off.

[ArtM]

Yes, quite right. Rotten eggs is the wrong thing to be smelling for. Also...

Some additional research indicates that the odor threshold for SO2 is 500 ppb to 1200 ppb or even as high as more than 2000 ppb. 500 ppb is in the "warning" range and 1200 ppb is in the "unhealthy" range so it's quite likely, given the variability of peoples' olfactory sense, that by the time you smell it, you're already in trouble.

In other worlds, "if you can't smell it, you're OK" is false.

ArtM

[DanielP]

"Jetting" observed at Halem'uma'u vent last night! WoooHooo![:0]

[Fishboy]

I found a neat collection of eruption photos that I think you'll all enjoy at this address: http://earthobservatory.nasa.gov/Natural...p?id=36090

Aloha pumehana,
Brian and Mary
Lynnwood, WA\Discovery Harbour