Seismologists are starting to dig deeper into the nuclear weapon testing in North Korea by measuring waves emitted through the earth from the explosions, just like a method for measuring earthquakes. By replicating some of the explosions within the earth here in the U.S. (not using nuclear explosions), scientists have been able to determine the magnitude and location of 5 different nuclear weapon tests coming from North Korea since 2006, and each test is continuing to get bigger.

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