A couple of mysterious booms Wednesday that rattled residents of the Port Angeles area seemed to be coming from the Strait of Juan de Fuca, but the cause remains undetermined.
The Peninsula Daily News checked with the Clallam County sheriff's office, the Coast Guard, Navy, Joint Base Lewis-McChord, Canadian Forces and the Weather Service, and no one could account for Wednesday's unusual sounds.
One resident, Michelle Kaake, heard two booms at her home. The first vibrated the floor and rattled the windows. She heard another one about five minutes later.
The newspaper reports that loud booms have been reported occasionally on the north end of the Olympic Peninsula for the past nine years without explanation.
Shallow earthquakes can cause loud booms, according to the U.S. Geological Survey website. “No one knows for sure, but scientists speculate that these 'booms' are probably small shallow earthquakes that are too small to be recorded,” the USGS website said.
But no earthquakes were recorded in the Clallam County area Wednesday, according to USGS seismic data
In 2012, a series of mysterious and disconcerting overnight booms and vibrations that kept Clintonville, Wisc. residents awake for three consecutive nights.
“The cracks in my floor, the cracks in my wall are getting worse,” Sharon Binger said Wednesday night at a town hall meeting held at a local high school that attracted about 400 residents. The booms are powerful enough to rattle dishes, say some, while others describe the sounds as underground fireworks, reported The Christian Science Monitor.
The USGS later reported that the mysterious booms that shook the town were the result of a 1.5-magnitude earthquake. Although not a huge event, the earthquake caused a swarm of several small quakes in a short time. Paul Caruso, a geophysicist from the USGS, told the local Fox News affiliate that most people wouldn't normally feel a 1.5-magnitude earthquake, but that the rock in Wisconsin is very old and well consolidated, allowing residents to feel otherwise sensitive rumblings.
The BBC reported in December that "mysteriously loud noises have been reported for hundreds of years across the world. In Italian they are called “brontidi” (thunder-like); in Bangladesh they are “Barisal guns”. US citizens call them “skyquakes”, “moodus noises” and in North and South Carolina, “Seneca guns." "
In a research paper, David P. Hill, scientist emeritus of the U.S. Geological Survey, explored some of the possible causes of the booms heard in various locations worldwide. Among the more plausible scientific are "mud volcanoes and/or explosive venting of gas; tsunamis or large, storm-driven waves; meteors; booming sands; rock bursts; local earthquakes; and distant thunder. The latter are the best documented and best understood natural sources of booming sounds. Linking the sound to the source can be challenging for a variety of reasons. Under appropriate wind conditions and atmospheric thermal (density) profiles, for example, the low-frequency component of a boom can propagate as a guided wave for distances significantly beyond the visible range of the source."