This week, seismologists were met with the unfortunate news that North Korea probably tested a nuclear weapon. (For more technical details on the detonation, see here.) The task of seismologists in the free world has been to confirm whether the North Korean government was truthful when they claimed they tested a nuke. Whether they realize it or not, scientists currently working to verify if North Korea has conducted a nuclear test are actually engaging in an exercise in intelligent design. They are trying to distinguish between naturally caused seismic energy and seismic energy which was artificially produced by an explosion caused by intelligence. Such studies are possible because explosions, particularly large ones like nuclear blasts, produce a distinctly different seismic signature from natural earthquakes:
Seismic sensors can register the strength and pattern of an explosion, and a nuclear blast gives off a clear signature — a graph of peaks and curves — that differentiates it from other kinds of shocks, according to Friedrich Steinhaeusler, a professor of physics at Salzburg University.
(Verifying Nuclear Test Blasts FAQ, Associated Press, in the Washington Post, Monday, October 9, 2006)
In short, nuclear explosions produce strong compressionary waves (called p-waves) with energy that travels like compressions along a slinky, and weak shear waves (called s-waves) with energy that moves up and down, like the motion created when one snaps one end of a rope. Naturally occurring earthquakes produce the opposite signature: stronger s-wave energy but weaker p-waves.
(Linked from “Monitoring Clandestine Nuclear Tests” at Lawrence Livermore National Laboratory)
Making such design inferences can require much scientific analysis. For example, “if an underground blast is smaller than one kiloton, it’s difficult to distinguish between the natural sounds of the earth and an actual explosion,” and “it takes a long time to interpret data” (see Verifying Nuclear Test Blasts FAQ).
But difficulties in detecting intelligent causation in seismic energy don’t prevent scientists from trying to detect, or reject design. When they do verify a nuclear explosion, they have made a design inference. One scientist stated in the overtly anti-ID Seed Magazine that the recent North Korean seismic event was not a natural event, but was designed: “The peculiarity of the seismic waves indicated there was an artificial explosion, not a natural earthquake.”