Did North Korea detonate a nuclear bomb yesterday?

Yesterday, the U.S. Geological Survey registered a 4.9 tremor in North Korea that originated roughly one kilometer underground, suggesting the test of a nuclear bomb. Read the full text here: http://mentalfloss.com/article/48881/6-other-major-discoveries-us-geological-survey#ixzz2Kj1qkCwp --brought to you by mental_floss!