A 6.3 magnitude earthquake, according to both the U.S. Geological Survey and the China Earthquake Administration, was detected in North Korea Sunday, just hours after the North revealed what it claimed is a thermonuclear device, specifically a hydrogen bomb. The testing of a thermonuclear device would be a significant step forward for North Korea, which is in the process of developing an effective nuclear deterrent against the U.S. and its allies. If North Korea tested the device revealed earlier, the North Korean nuclear crisis is about to get significantly more complicated.