James Dean

Florida Today

MELBOURNE, Fla. — A seismic jolt on the other side of the planet had a team of experts huddled at Patrick Air Force Base before dawn Sunday, alerting U.S. and international leaders of their alarming findings.

A global network of 3,600 sensors monitored around the clock by the Air Force Technical Applications Center, headquartered at Patrick, had picked up North Korea’s underground test of a nuclear bomb.

The center helped confirm that the blast registering 6.3 on the Richter scale was 10 times more powerful than North Korea’s previous nuclear test a year ago, and one of the most powerful nuclear tests detected since a ban took effect more than 20 years ago, Air Force officials told Florida Today.

“It lit up the international network, for sure,” said Glenn Sjoden, the center’s chief scientist. “There’s no mistaking the fact that there was a very large event in North Korea at their nuclear test site.”

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As Hurricane Irma approaches Florida, AFTAC, as the center is known, continues to analyze last weekend's test while watching out for any new activity.

A team may soon be dispatched to Texas — to a location unaffected by Hurricane Harvey — to take over the surveillance if Irma forces local personnel to ride out the storm with reduced staffing.

“It doesn’t matter if the hurricane hits us or not, we will have that 24-7 coverage,” said Chief Master Sgt. Michael Joseph. “Wherever we go, we will make sure the mission’s getting done.”

Patrick AFB is best known for the 45th Space Wing, which on Thursday will support SpaceX’s attempt to launch a rocket from Kennedy Space Center. Patrick’s 920th Rescue Wing recently helped rescue more than 230 Harvey victims in Houston.

AFTAC is perhaps a less visible tenant at the base, but its electronic eyes on the ground, under water, in the air and in space play a critical role in reporting nuclear explosions to the Department of Defense and the Comprehensive Nuclear Test Ban Treaty Organization.

About 850 of the center’s roughly 1,000 employees, about half military and half civilian, work at Patrick. Their motto: "In God we trust. All others we monitor."

The team often detects seismic events that don’t rate as national security concerns, such as earthquakes and mine explosions. One exception was the 2011 the Fukushima Daiichi nuclear reactor meltdown in Japan, which prompted a major response.

But after Saturday night’s blast in a mountainous region of northeastern North Korea, an AFTAC team briefed leaders on preliminary findings by 2:15 a.m. ET Sunday at Patrick.

“It’s safe to say that we knew very quickly and could characterize that signal very rapidly in order to have a very good idea of what likely occurred,” said Col. Steven Gorski, the AFTAC commander.

Analysis of the test continues, with a WC-135 aircraft sampling international airspace for any radioactive debris released.

The test by itself doesn't prove an ability to weaponize such a bomb. But it came on the heels of missile tests that have heightened fears that North Korean missiles might now be able to reach the U.S.

“Everybody should be concerned about North Korea and the threat that they pose to their neighbors and to the United States,” Gorski said.

Now AFTAC, like the rest of the

Florida coast, must also contend with a major hurricane's potential arrival in the coming days.

“A hurricane and a North Korean nuclear test in the same week is a significant test, and they’re doing extremely well,” Gorski said of his team.

Follow James Dean on Twitter: @flatoday_jdean