Comforting news coming out of the U.S. Geological Survey (via the NYTimes.com):
The test explosion in North Korea registered just slightly higher than the rogue nation's fizzle-y nuke test in 2006. Whereas Hiroshima was a 15 kiloton explosion, the data from the North Korean explosion corresponds to an atom bomb of about 4 kilotons.
From the Times:
"Was it another fizzle?" asked Hans M. Kristensen, a nuclear expert at the Federation of American Scientists. "We'll have to wait for more analysis of the seismic data, but so far the early news media reports about a â€˜Hiroshima-size' nuclear explosion seem to be overblown."