How the weather amplified the loud ‘booms’ heard across the Salt Lake Valley
SALT LAKE CITY ( ABC4 ) — This afternoon, loud 'booms' shook the Salt Lake Valley, spreading widespread confusion across several communities, even those located far from the source.
The booms were attributed to the Tooele Army Depot which said they had conducted a regular operation to detonate old and unsafe munition. However, this time, the weather conditions amplified the vibrations of the detonations.
ORIGINAL STORY: Large booms felt and heard throughout Salt Lake Valley – Here's what we know
Utahns reported hearing the booms as far east as Kamas and as north as Layton, where some Tooele residents said they did not hear or feel anything at all.
The Tooele Army Depot released a statement saying the detonations "propagated further than normal" due to the current weather conditions, as "increased moisture in the ground" can amplify the vibrations.
ABC4's Chief Meteorologist Alana Brophy further explained that weather affects how sound travels as it can distort sound waves and affect the speed at which they travel.
"Our conditions today could have played a role into why those loud booms had a far reach," Brophy said.
Brophy said one possible factor is temperature as it plays a role in how quickly sound travels.
"Sound travels faster with warmer air because molecules move more quickly. Less dense air will also allow for sound to move faster and we see less dense air when we have lower humidity levels like today," Brophy explained.
Another factor is low-level cloud cover — which was seen in Salt Lake, Utah, and Tooele Counties today — as Brophy said it can "refract sound waves or bend them toward the ground, which actually makes them sound louder to folks who hear them."
She added that wind can also refract sound waves and bend them over long distances.
"Wind can change the speed of sound waves as they travel, distort the sound waves by speeding them up or slowing them down," Brophy said. "The wind [can] even cause refraction, which causes the sound waves to bend over long distances."
Wade Williams, Tooele Army Depot public affairs officer, said this was the ninth time they detonated obsolete munition this year. He said while what they did today is what they normally do, the weather played a role in magnifying the effects of the detonations.
"We only conduct these operations when weather conditions are right to mitigate the sounds and shaking from the detonations," he said. "We do our best to be good neighbors while also accomplishing our mission."
