Interestingly, the yield is in considerable debate. With a quake magnitude of 4.2 (USGS), I can't derive a yield as low as the South Korean claim of 550-800 tons (TNT equivalent). Such a yield would either be a fizzle (if it has a sharp leading edge in time) or a hoax (using a LOT of chemical explosives). For magnitude 4.2, I get a yield of kilotons, though it depends a lot on geological conditions for which I don't know how to compensate or calculate.
Thumbing around the web, I find Jane's Defense Weekly agrees that it needs to be "2-12 kton" to match up with the 4.2 magnitude. The Russians 5-15 kton. Other reports come in with lower figures and possible fizzles.Posted by duver001 at October 9, 2006 11:36 AM