A North Korean nuclear bomb test was detected in Alaska. State seismologist Michael West said Alaska Earthquake Information Center seismometers clearly registered the underground blast Saturday.
“An explosion of magnitude 6.3 is something that can be viewed or recorded, really all around the globe,” West said.
West says the center seismometers, which regularly detect earthquakes, also pick up other disturbances, like landslides and detonations at mines. He says signals from explosions like the underground North Korean nuke test, are completely different from those of an earthquake.
“During an earthquake, the Earth sheers in very complicated ways and that creates a whole mix of very different looking seismic waves that propagate out in all different directions,” West said. “An explosion is actually a much, much simpler source. It has one very simple motion. Everything is outward from the source.”
Wests notes that the nuke test, although significant at magnitude 6 point 3, was not strong enough to effect the balance of tectonic plates.
Dan Bross is a reporter at KUAC in Fairbanks.