Harperdog writes "A great article detailing how GPS can help detect secret nuclear tests, giving the US more reason to ratify the Comprehensive Test Ban Treaty. Here's a quote about the recent North Korea test: "At the time, however, the May 25 bomb also sent a different signature, this one into the atmosphere. It did not release radioactive gas or dust, as would be the case for a bomb detonated on the Earth's surface. Rather, it released a shockwave — a bubble of disturbed air that spread out from the test site across the planet and high into PDF the ionosphere. ""
Link to Original Source