FACT FOCUS: Conspiracy theories falsely blame Colombia earthquake on Alaska research program

An enduring conspiracy theory has resurfaced on social media after a 7.4 magnitude earthquake hit western Colombia on Monday , with users blaming a research program in Alaska for the disaster.

Posts falsely claim that the earthquake, which has killed at least 270 people and left widespread damage, was caused by the High-frequency Active Auroral Research Program, or HAARP, which studies the properties and behavior of the upper atmosphere.

But the earthquake was caused by natural movements in the Earth's crust. Experts say it had nothing to do with human activities.

Here's a closer look at the facts.

CLAIM: HAARP caused the 7.4 magnitude earthquake in western Colombia on Monday.

THE FACTS: This is false. The U.S. Geological Survey says that the Colombia earthquake was caused primarily by “strike-slip faulting” — when two sections of Earth’s crust move horizontally past each other. The epicenter of the earthquake is within the country's Pacific region, which lies along the “Ring of Fire,” a line of seismic faults encircling the Pacific Ocean where most of the world's earthquakes occur.

“No human endeavor caused this earthquake,” said Suzan Van der Lee, a seismologist and professor at Northwestern University. “The Colombia earthquake occurred in a region with many natural earthquakes.”

She said there are cases where human activity in shallow parts of the Earth's crust such as gas extraction or waste water injection has caused small- to moderate-magnitude earthquakes. But the earthquake in Colombia occurred at a depth of 110 kilometers — at least 10 times deeper than any caused by humans, Van der Lee noted.

The University of Alaska Fairbanks has operated HAARP since 2015. It was previously run by the U.S. military, which still owns the land where the program is located.

HAARP has been the subject of conspiracy theories since the military started building it in the early 1990s. In addition to allegations that it can cause earthquakes, believers have falsely claimed that it is a mind-control device and that it can control the weather.

Researchers at HAARP study the physical processes occurring in the highest parts of Earth's atmosphere — the thermosphere and ionosphere — by using high-frequency radio transmitters to heat small regions and observing the effects.

The program uses many scientific instruments, but the one that is often at the heart of conspiracy theories is its Ionospheric Research Instrument (IRI), the world's most powerful high-frequency radio transmitter.

“I can confidently state that there is ZERO physical basis for radio-frequency transmissions having any effects on the occurrence of earthquakes,” said Dean Whitman, a geophysicist at Florida International University, who called hypotheses about HAARP's supposed impact “ridiculous.”

He pointed to a number of reasons the claims are not valid. One, the energy released by the Colombia earthquake was “much larger than that released by even the largest hydrogen bombs” and “millions of times larger than the energy produced by the HAARP array.” Two, HAARP's equipment is pointed upward, not downward toward where earthquakes occur. And three, the radio transmitters it uses produce electromagnetic waves that would not be able to cause earthquakes because they “involve a completely different set of physics."

The search for those buried in the rubble of the Colombia earthquake is ongoing . Tons of aid from regional partners began to roll into the country on Wednesday.

Find AP Fact Checks here: https://apnews.com/APFactCheck .