1,500lb TNT-force earthquake rocks Utah before surprise source reveal

A 3.1-magnitude earthquake rattled Utah on Wednesday evening, sparking questions over what caused the sudden tremor.

Moments later, reports of the apparent earthquake began circulating on social media. 

Data from the US Geological Survey (USGS) revealed that it was not a natural earthquake, but an explosion at a mining site. Data showed that it occurred at a depth of zero feet, indicating that the blast took place at the surface.

The blast, equivalent to 1,500 pounds of TNT, was recorded outside Maeser, an area surrounded by 3,205 mines and mining claims.

News about the earthquake being linked to an explosion sparked a flurry of comments online, with one person saying: ‘That must have been a pretty big amount of explosives.’

Another asked: ‘Was it normal or an accident, and was anyone hurt?’

People living nearby, however, reported feeling no shaking. 

One person within Vernal city limits, about nine miles from the epicenter, said they ‘did not feel this earthquake,’ while another added: ‘I live here and didn’t feel a thing.’

A 3.1-magnitude earthquake rattled Utah on Wednesday evening, sparking questions over what caused the sudden tremor

The USGS detected the seismic event at 4:59pm ET, with only one person reporting shaking to the agency.

Utah experiences frequent seismic activity and is home to more than 200 active faults, including the Wasatch Fault Zone, which runs beneath major population centers such as Salt Lake City.

Wednesday’s explosion occurred about 171 miles east of Salt Lake City.

Mining explosions can produce seismic waves that resemble those generated by earthquakes, causing monitoring equipment to register the blast as a magnitude event.

However, explosions typically occur at or near the surface, while natural earthquakes originate deeper underground when built-up stress causes rocks to rupture along a fault.

It remains unclear which mining operation caused Wednesday’s blast or whether the explosion was planned. No injuries or damage had been reported.

The Utah blast came just days after another manmade seismic event was recorded off Florida’s coast. 

On Tuesday, the USGS detected a 3.9 magnitude earthquake east of Flagler Beach.

On Tuesday, USGS detected a 3.9-magnitude earthquake east of Flagler Beach. The agency labeled it as an ‘experimental explosion’ 

It was listed with a depth of zero feet, indicating the seismic source was at or very near the surface, a characteristic more consistent with an explosion than a typical tectonic shake.

The location is about 20 miles from where another event was recorded on July 16, east of Ponce Inlet, an area where the US Navy is known to conduct Full Ship Shock Trials (FSST).

These controlled underwater detonations test how new or upgraded warships, like aircraft carriers or combat vessels, withstand battle-like explosions near mines or torpedoes.

A Navy spokesman said after the July 16 event that the future USS Ted Stevens had successfully completed the first of two planned trials, part of the certification process for its DDG 51 Flight III destroyer program.

In 2021, a test explosion occurred near its new aircraft carrier, the USS Gerald R Ford, also off the coast of Ponce Inlet.

The USGS records experimental explosions because its network of highly sensitive seismographs detects the ground vibrations they produce.

Seismologists then analyze the signals to distinguish human-made blasts from natural earthquakes.

Such events are typically linked to controlled military exercises, including underwater ship shock trials, as well as scientific seismic research and industrial mining operations.

These Navy tests use large explosive charges, such as tens of thousands of pounds in past cases, to simulate battle conditions like nearby mines or torpedoes and test warship resilience.

No damage or injuries are expected or reported, as these are planned, permitted tests with environmental considerations for marine life.

The Navy has been conducting them for decades after discovering that nearby explosions can knock out critical ship systems without inflicting significant physical damage.