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Hill AFB conducts large detonations; Nearby residents report earthquake-like rattling

Posted at 8:13 PM, Aug 31, 2020
and last updated 2020-08-31 22:13:15-04

HILL AIR FORCE BASE, Utah — Hill Air Force Base officials conducted major detonations Monday afternoon, which they confirmed after some Utahns reported hearing and feeling what they thought may have been an earthquake.

Monday's detonation operation, which included destroying a rocket motor and solid propellant of a Navy ballistic missile, took place at 12:11 p.m. at the Utah Test and Training Range.

The detonation "may have been the cause of the shaking and rumbling that local residents noticed this afternoon," said Michelle Cottle, chief of the 75th Civil Engineer Group’s environmental branch.

The base previously announced that it would conduct detonation operations from June through September about two or three times a week.

Cottle added that they take atmospheric readings to determine if conditions are "acceptable" before such detonations, which include more than 10,000 pounds of net explosive weight.

"If the model predicts that noise is going to be louder than permitted levels at locations along the Wasatch Front, a detonation will be delayed," she said Monday, adding: "With the variability of upper atmospheric weather conditions this time of the year, the model does not always accurately predict sound levels along the Wasatch Front."

Cottle said similar instances occurred in 2014 and 2017.

The range is the only location in the United States capable of these specific detonations to destroy the rocket motors, Cottle added.