North korea supposedly has a WMD that can deplete oxygen in the surrounding area of the blast cite. So this could possibly lead to suffocation for a large radius surrounding the blast site.
http://www.fas.org/irp/world/rok/nis-docs/hwang1.htm
Three are unconfirmed reports of bombs capable of depleting oxygen within a limited area upon explosion (most likely fuel-air explosives), in North Korea’s weapons inventory.
Is a weapon like this possible, or are there too many mols of oxygen for this to really be feasable? Even if it has chemicals on it that bind to oxygen and make it worthless for respiration, even a few tons would still only negate a few tons of oxygen
http://www.physlink.com/Education/AskExperts/ae650.cfm
1 cubic foot of air is 0.0807 lbs and 21% oxygen, so 0.017 pounds of oxygen per cubic foot. A square mile one foot deep would be 28 million cubic feet. So even that would require 474 tons of oxygen to be neutralized, and that is assuming a one foot deep area. The real area would need to be much deeper, tens of feet. Warheads are only a few tons.
is this a possible WMD or is there some other way that it would neutralize oxygen?