N. Korea nuclear test recorded
This plot shows two raw seismograms recorded at the Global Seismic Network station MDJ in China. In blue is the May 25, 2009 North Korean nuclear test, and in red is the record of the most recent explosion on February 12, 2013. These records are nearly identical, except that the amplitude of the most recent event is substantially larger. This is consistent with reports that the latest nuclear test in North Korea was more powerful than its predecessors. (Figure: Andrew Frassetto, IRIS)
Creepy lava tube picture