Earthquake Booms, 'Seneca Guns', and Other Sounds - Earthquake "booms" have been reported for a long time, and in the US they tend to occur more in the Northeastern US and along the East Coast. There have been many reports of "booms" that cannot be explained by man-made sources. No one knows for sure, but scientists speculate that these "booms" are probably small shallow earthquakes that are too small to be recorded, but large enough to be felt by people nearby. In New Madrid, Missouri, there are accounts of "artillery-like" sounds that were said to have occurred before or during the New Madrid earthquakes of 1811-1812. [Mystery booms coming from deep in the plate boundary were reported in Indonesia for many months before the December 2004 quake and tsunami.]

Meteors exploding in the atmosphere are a possible cause of other unexplained booms, which are sometimes described as skyquakes.

There does not appear to be any agreement on what causes the booms of the 'Seneca guns'. They have been occurring in several places around the eastern U.S. and in India for at least a century or two.


MYSTERY BOOMS - November 2013

Arizona - 11/25 & 11/26/13 - Residents hear, feel earthquake-type booms. Residents around Chino Valley reported hearing one or two loud booms and feeling their homes or business buildings shake on the mornings of Nov. 25-26. The Arizona Earthquake Information Network Director said the network's sensors didn't detect any earthquakes here, so if they occurred they probably were smaller than a magnitude of 2.5. And it would be hard for people to feel one smaller than a 2.0 magnitude.
Chino Valley police and fire officials, and the Yavapai County Sheriff's Office all received calls, but none of the three agencies reported any damage or injuries to residents. The U.S. Geological Survey website, which lists earthquakes recorded around the world, reported none for this area, either. However, by the afternoon of Nov. 26, 17 Chino Valley residents responded on the website that they had felt something that they thought was an earthquake. The Drake Cement plant north of Paulden said they had not done any blasting either of the two days, and a spokesperson said that employees working in the plant office yards away "hardly hear" noise from their blasts, and generally see only a puff of dirt. People who heard the boom on Nov. 25 said it sounded like something fell on the roof of the building they were in or like a sonic boom. More people responded Nov. 26 to hearing a boom or booms, windows rattling and then feeling the floor move.
One resident heard the Nov. 26 boom at about 8:35 a.m. and felt the floor of his office move. "I was sitting here at the office and all of a sudden, the floor moved up and down under my feet." He immediately called his wife at home three miles away, and she also heard the loud bang, but initially thought their dogs knocked over something inside the house. She also said the dogs began barking.
One rsident said she first noticed a change in her cats' behavior before the Nov. 26 booms hit while she was getting ready for work about 8:40 a.m. "They were acting really goofy, running all around and then hid under my bed." Also, her windows began to shake prior hearing the two booms. She then heard the booms and her tile floor moved back and forth under her bare feet. For12 years of her childhood, she lived in Highland, Calif., only a mile from the San Andreas fault, and felt many earthquakes. She described the movement of those shakes as a rolling motion, like standing on pipes. The movement here was different, she said. "This one shook back and forth. It shook me up." She has a theory that the long-period comet currently reported near the Earth, which she's learned is causing different kinds of disturbances around the world, could be the cause of the booms and shaking here.

Arizona - 11/26/13 - Mysterious booms rock Verde Valley. More mysterious 'booms' reported in Verde Valley area. Last year, about this same time, residents in Verde Valley heard some mysterious, unexplained booms.
"It was a whole series of booms. Up to six or seven. It was fast, it went loud. We were quiet and then my daughter down the hall screams really loud, ‘Did you hear that?' I sat there for a second and I heard another set." Residents in communities in and around Verde Valley and as far as Flagstaff called 911 or their police and fire departments to report the strange booming sounds. "It sounded like thunder, but underground. Like muffled thunder. And all the dogs in the neighborhood, all of them that were outside all started barking at once."
CBS News first received reports of the explosion-like noises shortly after 5 p.m. Tuesday and began checking with law enforcement and government sources. The U.S. Geological Survey reports no significant earthquake activity in Arizona that could have created the booms. The Yavapai County Sheriff's Office had deputies in the area who either heard it or tried to respond to resident calls. They found nothing.
Last year around this same time, similar mysterious booms were heard by other residents in the Verde Valley. There is some military activity that takes place with the U.S. Air Force flying planes over the area. "It is kind of strange that it would be re-occurring and, in that case, maybe it indicates some sort of man-made source. Who knows?"
The Sedona Fire District dispatched a crew to check a report of a strange odor, but that was unfounded and may not be related to the sounds. The Camp Verde Marshal also received a number of phone calls about the booms. Officers found no evidence of any explosions. But the Verde Valley contains large expanses of uninhabited land. "Maybe when the light comes back they'll find something." "It was just, ‘boom-boom-boom-boom-boom all over the Verde Valley."
Reports of similar booms are once again being called in to the Yavapai County Sheriff's Office. This time, primarily from the town of Chino Valley. "The way to describe it is like a hammer being slammed down next to the house. It was two hard hits and the house jumped, if felt like a jump, and I could hear the windows rattle a little bit, some glasses rattled." The first mysterious sound happened Monday around 10:20 a.m. and the second one at 8:40 a.m. Tuesday. It was a vertical jolt and after having lived through plenty of earthquakes while a resident in Southern California, a resident was sure it wasn't one. No earthquakes were reported in Arizona by the U.S. Geologic Survey on Tuesday.
The Verde Valley area had the same type of mysterious sounds about this time last year near Sedona. Last year, the calls went to the sheriff's office and the fire department. The Yavapai county Sheriff's Office on Tuesday said it checked out the reports. "Deputies conducted searches on both sides of Mingus Mountain, Prescott and Verde basins, and the source of the booms is classified unfounded."

Washington - 11/26 through 11/28/13 - What are they? Rumblings, 'booms' heard anew on parts of the Peninsula. Residents between Port Angeles and Sequim reported hearing low, sustained rumblings and in some instances loud booms from Tuesday to Thursday last week. At least 15 people posted comments to the Peninsula Daily News’ Facebook page describing the sounds, which some say have been heard up and down the Strait of Juan de Fuca for months, if not longer.
“Yeah, it’s kind of strange. Everybody around here hears it. It rattles windows.” They never see any ships in the Strait nor planes overhead accompanying the rumbling sounds, which one described as being heard “just about every day” last week. “If you’ve never heard it before, it almost sounds like a big ship maybe reversing propeller.”
Others living in the Graysmarsh area of Sequim and up on Black Diamond Road also reported the rumblings Tuesday and Wednesday night. “It’s just another peculiarity of the North Olympic Peninsula." A Diamond Point resident said that people in that area hear “this all the time.”
the public affairs officer at Naval Air Station Whidbey Island said Navy jets were practicing all last week, except on Thanksgiving, and for most of November at the station’s Ault Field, just north of Oak Harbor and about 60 miles east of Port Angeles. “I can’t say definitely that that’s what they heard. All I can do is confirm that we’ve been having operations.”
EA0-6B Prowlers and EA-18G Growlers pilots practicing day and night for aircraft carrier landings at the air station might sound like rumbling, though no aircraft flying to and from the station would produce booms. “We aren’t doing anything you could really characterize as a loud boom. That’s not characteristic of normal aircraft operations.” Questions from the PDN about rumblings in the area came not too long after similar inquiries from a news website on Orcas Island. “I can tell you that over [on] Orcas Island, they were hearing rumbling in the distance, and we were doing operations at that time.”
The public affairs officer for Canada’s Maritime Forces Pacific based at the Canadian Forces Base in Esquimalt, B.C., said no Canadian naval ships were practicing firing on any of the base’s test ranges. Once such range is in the Strait of Juan de Fuca area. “The ranges were not active this week at all." The sounds he’s heard have not been booms and have not sounded like aircraft. “It doesn’t sound like jet aircraft to me. I’ve heard a lot of jet aircraft, and that’s not the way I would describe it.”
Last week was just one in a long list of multiple reports of mysterious booms or rumblings in the central part of the Peninsula. Rumblings earlier in August were thought to be Navy jets at Whidbey Island, while booms heard along the Dungeness River in April 2012 were attributed to a propane cannon set up to protect newly planted fields from birds. “We have not pulled [the cannon] out to use [on] Thanksgiving or anytime recently. No, it wasn’t us.”
A series of booms around Port Angeles in 1982 was blamed on naval exercises in the Strait. Unexplained booms were reported in Port Angeles in 2006 and 2007. Booms were heard in Dungeness, with houses shaken and a report of at least one broken window. In 2009, Port Angeles was again shaken by unexplained booms. In 2011, reported booms were determined to have been thunder.

Canada - 11/26/13 - People on Montreal's West Island and in the Vaudreuil region reported a loud boom followed by a vibration at about 8 p.m. Tuesday. A strange bang and flash of light sighted near Montreal on Tuesday night may have been a meteor. Hundreds of people took to Twitter and Facebook on Tuesday around 8 p.m. (ET) to report the sight. And though researchers have yet to confirm it – either through sonic radar or surveillance video – they say that it was most likely a meteor.
Reports have come from throughout the Ottawa region, through Montreal, Laval, and as far south as upper New York state, near the city of Plattsburgh. There have been no reports of damage. And, although a meteorite strike can often be detected by seismographs, Earthquake Canada said it had not registered any such event. The United States Geological Survey also said it had no recent reports of any quakes in the region.
At this point, researchers are hoping to gather video or photos of the event in hopes of figuring out where possible meteorite fragments may have landed. “The fact that there was a large sonic boom indicates that it was larger than average. Most meteors we see at night are the size of a grain of sand. This was much larger – anything between the size of a La-Z Boy chair to the size of a car. The question now is, what happened to it?”

South Carolina - 11/25/13 - Reports of mysterious “booms” light up Twitter on Monday evening. Twitter came alive with reports of loud booms off of James Island. It happens at least once a year: Residents along the coast report hearing and feeling booms that rattle their windows and shake their walls. The media investigates, calling local seismologists and the Air Force asking if they might know the source of the explosion and – nothing. Everyone shrugs their shoulders and mutters “Seneca Guns”, an unexplained phenomenon that dates back more than 100 years.

Pennsylvania - 11/30/13 - Residents report hearing "boom" in Wellsville, other counties. York County residents reported hearing a loud "boom" on Saturday that may have been York County's latest earthquake. "A lot of reports have come out of the Wellsville area." The reports ranged from Lower Allen Township in Cumberland County to Biglerville in Adams County. Although that's a sizeable area, the seismograph at Millersville University -- the closest one to the area -- did not register anything.
The explosion happened around 9:20 p.m. They checked in with Fort Indiantown Gap to see if they had been firing any heavy artillery at that time, and found out they had not. The shifting rock under the affected area might be diabase, the type of igneous rock that runs under the very seismically active Dillsburg area. "Diabase is so dense, when it shifts, everybody knows about it. Diabase, "literally explodes from pressure."
As for what caused it, the earthquakes in recent years might be tied to heavy rainfall. York County received 9.11 inches of rain in two days last month. "That's a theory."

Pennsylvania - 11/23/13 - Police say source of booms still unexplained. Police are puzzled by reports of booms heard throughout Philadelphia last week. Reports came in last week from some residents of the Woodland Hills neighborhood about hearing booms late at night. "We got a call on Saturday about booms around Azalea Drive and Chaney Avenue. Our officers went out there but couldn't find anything." The sounds might have originated in the country but were picked up by city residents.
Earlier this year it was discovered that a similar boom was caused by an explosive target used to blow up a beaver dam in the Williamsville community. The targets, which are often available for purchase at pawn shops and gun shows, explode when hit by a high-powered rifle round.

Connecticut - 11/29/13 - Mysterious "Booms" Heard in Southeastern Connecticut. Police in several southeastern Connecticut towns were flooded with calls. Stonington police said they received several calls from people across the town who reported hearing at least four loud "booms".
The mysterious booms turned out to be an earthquakes. Two organizations that track seismic activity have confirmed that the region experienced an earthquake on Friday, answering questions raised about the mysterious booms heard by residents from Montville to Mystic. The U.S. Geological Survey recorded a 2.1 magnitude earthquake at 9:05 a.m. Friday that was centered about 2 miles east of Conning Towers-Nautilus Park. The Weston Observator reported two earthquakes, one at 9:05 a.m. and another at 9:42 a.m..
The quakes were recorded somewhere in the area of the Thames River, close to Ledyard. The noises produced by the earthquakes led to numerous calls to local police and fire departments, which searched the area looking for signs of an explosion. Residents were reporting that their houses shook from the booms. There were three “just incredible, boom, like explosions,” in thirty minutes.