So we know this stuff is bad, but...

April 20, 2010 10:56 AM

How many tons of ash has the volcano in Iceland erupted?

I'm looking for numbers about what exactly Eyjafjallajoekull is shooting out. I've found 150-300,000 tons of CO2/day, but gas isn't nearly as fun as solids.

This will tell me what's in the ash, and this will tell me about the magma, but nothing about how much ash! (Although maybe that's "Tephra fallout from eruption plume"?)

posted by jenmess to Science & Nature (11 answers total)

About 100 million cubic meters of airborne tephra, most of which was very fine grained [pdf] and therefore classifiable as ash.
posted by jedicus at 11:06 AM on April 20, 2010

That's for the first 72 hours of the eruption, by the way. Presumably more has been released since.
posted by jedicus at 11:07 AM on April 20, 2010

Oh, to convert to tons we can use some general information about the density of volcanic ash. Since the tephra in question is very fine-grained, we'll use the values for pumice fragments, which are the lightest kind of ash in that table. At 100 million cubic meters and 700-1200 kg/cubic meter, we get something like 17 billion - 120 billion kg. If you want tons (the 2000 lb variety), that's 18.7 million - 132 million short tons.

For comparison, the 1980 eruption of Mt. St. Helens released 540 million tons of ash.
posted by jedicus at 11:16 AM on April 20, 2010

aside: the total surface (land only) of the EU is about 4.32 millions sqkm; neglecting mountains, and considering an altitude of up to 37,000ft (11km) for the airspace I get an approximate volume of 47.52 millions cubic km. (1 cubic km = 10^9 cubic m) which, divided by the above quoted volume of eject (tephra, ash, etc) gives me an average volume ratio of 1 part ash over 475 millions parts air.
It's obvious that the distribution is very inequal, but I'm starting to suspect that all this was a little overestimated by the EU authorities.
posted by _dario at 12:47 PM on April 20, 2010

Caveat: I know nothing about jet engines, not good at physics, and very naive assumptions are made below.

Berlin to Paris is ~1000 km = 10⁶ m.
Jet engine intake is ~2 m in diameter, 3.14 m².
So during this travel, the air intake is 3.14*10⁶ m³ per engine.
Using 1 part ash / 475 million parts air gives 0.0066 m³ ~ 6.6 liters ash.
posted by flif at 2:05 PM on April 20, 2010 [1 favorite]

Eruption ejecta totals are usually expressed in cubic kilometers, simply because units like "kilograms" are so ridiculously small. Mt. St. Helens released about a cubic kilometer of ash.
posted by Chocolate Pickle at 5:14 PM on April 20, 2010

flif, you make an excellent point.
posted by _dario at 8:32 PM on April 20, 2010

flif, you miss one important argument. Air intake is not equal to area x distance travelled.
Air flow through GE-90 (Boeing 777 engine) is 1350kg/sec. Density of air at 35000ft is .1841kg/m3. This engine moves 7,300m3/sec of air through it.
1 hour flying..2.6x10^7 m3 of air.
posted by defcom1 at 9:41 PM on April 20, 2010

defcom1: exactly. According to flif's calculation, a theoretical plane, flying across from Paris to Berlin in my theoretical "same density of ash everywhere" sky, with its engines turned off would intercept 6.6 liters ash. Per engine.
posted by _dario at 12:58 AM on April 21, 2010

huh? I must be missing something :( (I'm not disagreeing with your statement, just puzzled...?) Ash BAAAAD. And off topic. Sorry OP.
posted by defcom1 at 5:56 AM on April 21, 2010

well why don't we up and make an infographic about it
posted by soma lkzx at 2:14 PM on April 21, 2010