Mystery Booms From The Sky (Skyquakes)

More on Richmond's mystery booms

More area residents are shaken up about booms

BY JULIAN WALKER AND PETER BACQUE
TIMES-DISPATCH STAFF WRITERS

Nov 23, 2004

HATLEY MASON / RTD

Reports of the mysterious booms first felt in North Side neighborhoods are now coming from other city sections and beyond.

Folks from the Fan District, Lakeside, Short Pump and New Kent County all say they have sensed the shock.

Richmond leaders have even been contacted by officials from Fort Wayne, Ind., and several Canadian provinces where similar booms have been felt recently, city emergency services spokesman Bill Farrar said.

"We've gotten anecdotal stories, suggestions and theories from all over the place," he said. "But from what has been described to me, I don't believe we are dealing with the same things."

What exactly the city is dealing with remains unclear.

The booms began Nov. 2 and have occurred several times a week since. Most have been localized in North Side neighborhoods. After one of the bigger booms - Sunday about 12:45 p.m. - authorities logged 250 calls to 911 in 90 seconds.

City officials have dismissed construction firms, quarry outfits and railroad companies as the source of the noise. They have ruled out military exercises and aviation activities. Public utility personnel have turned up no evidence of a problem in gas, water or sewer lines.

And scientists say their instruments show no signs of earthquakes in the Richmond area.

"If a human being felt an earthquake in the Richmond area, and it was indeed an earthquake, we would record it on one of these [seismograph] stations," said Waverly Person a geophysicist with the U.S. Geological Survey's National Earthquake Information Center in Golden, Colo. "And we recorded nothing."

The region's long-inactive coal mines are not likely the cause of the reported booms and shaking because none are near North Richmond, the Fan or the near West End, said geologist David Spears with the Virginia Division of Mineral Resources in Charlottesville.

"There's nothing resembling gas- or coal-bearing [rock] strata in the area," he said.

The collapse of old, man-made underground structures, such as shallow subway tunnels or water conduits, could cause a shake perceptible to people but not deep enough to register on seismic scales, ventured James Beard, Virginia Museum of Natural History geology curator.

"Whatever this is," he said, "it is happening relatively close to the surface because they are not picking it up on nearby seismographs."

Another possibility, Beard said, is shifting earth from saturation of the ground from recent rain events, including the remnants of Tropical Storm Gaston. But in that case, he explained, the booms would be followed by landslides.

For now, city officials are considering all options.

Advanced audio equipment that will help pinpoint the origin of the booms will be set up to monitor North Side neighborhoods and a seismic activity device is on its way to Richmond, Farrar said.

"There's a lot of energy being expended," he said. "We're continuing to look for anything that might explain this."
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And a sposisble solution But one which raises more questions than it answers - very odd.

'Pressure devices' linked to Richmond's mystery booms

From NBC12 News
Tuesday, November 23, 2004


Richmond fire officials say they have uncovered several devices in North Richmond that are at least part of the reason residents in the area have heard loud booms at various times since November 2nd.

Fire Captain Mike Martin says the items recovered are “pressure producing devices, not incendiary devices.” Martin says the items would produce a loud noise “…and a blast.” He says they could be dangerous to anyone standing close by.

Martin says the devices were found in several locations near Laburnum Avenue and Hermitage Road both above and below ground. He says the areas are being considered a ‘crime scene’ and that authorities are processing these items as evidence.

It is understood that at least one of the devices was recovered intact.

Richmond Police, Fire and Public Utilities crews started a combined search about 8:30 this (Tuesday) morning after deciding they had an idea what might be causing the noise. Martin says they didn’t find exactly what they were looking for but something “very close.”

The 'booms' started in Richmond on election day and have happened several times a week since. Most have happened on the north part of town. On Sunday, authorities got 250 calls to report an afternoon boom.

City officials had ruled out construction, railroads or quarries, along with public utilities, military exercises and aviation activities.

--------------------
(c) 2004. Jefferson Pilot Communications.
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And back to the Fort Wayne booms as mentioned above with the similarities between the two:

Richmond Is Not Alone


Mysterious booms in the city continues to be a hot topic-- not just in Richmond, but also in Fort Wayne, Indiana.

Residents in Indiana say the story there is the same-- loud, unexplained booms. Officials in Richmond tell me they don't know if it's the same cause, but the signs are all too familiar.

Witnesses in Indian describe windows rattling, the whole house shaking, something lasting only a few seconds, and resembling an explosion from under ground.

In Richmond, you might remember these "sounds" beginning Election Day; in Fort Wayne, they date back to august.

The response of Fort Wayne authorities resembles that of Richmond: while many theories are being explored, they say they can not definitively identify the cause at this time.

Richmond officials have talked with officials in Fort Wayne, who were unaware of the booms here. They are comparing notes and will continue to stay in touch.
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More on the Richmond blasts

Richmond, Va., Blasts Said to Be Vandals


Nov 23, 9:14 PM (ET)

By BOB LEWIS


RICHMOND, Va. (AP) - Mysterious blasts that have rattled a city neighborhood off and on this month appear to be the work of pranksters or vandals who placed small explosive devices in city sewers, authorities said Tuesday.

Investigators said the homemade cylindrical devices didn't appear designed to kill or injure.

"It's a pressure-producing device, not an incendiary device," said fire department investigator Capt. William M. Martin. "It will cause what would be perceived as an explosion, but it doesn't leave a crater. It does make a large amount of noise."

Martin described the devices as ranging from 4 inches to a foot long and up to 6 inches around; he declined to discuss how many had been found. A search for more continued.

The blasts have occurred since Nov. 2 - but just on nights and weekends. Residents became so frightened that nearly 400 packed a community meeting Sunday.

Sara Driggs said the first blast jarred her family as they watched election returns.

"It's the unknown aspect of it," she said. "Hearing the boom is an experience like seeing a mouse. You know the mouse won't hurt you, but it startles you."
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And a resolution - smart arsed kids??

Teenager charged in booms that frightened neighborhood


By the Associated Press

Published November 25, 2004

RICHMOND, Va. -- Authorities have arrested a 15-year-old resident of the neighborhood where mysterious booms have frightened residents since the beginning of the month.

The teenager, who was not identified, was charged Wednesday with possessing or manufacturing an explosive device. That crime, a felony, carries a maximum penalty of 10 years in prison.

Other youths also might be involved, according to authorities, who said a citizen tip led them to the suspect.

The explosions were caused by a simple chemical reaction, a city public works spokesman told the Richmond Times-Dispatch. Three devices recovered by police earlier this week were made of common materials, including plastic soda bottles.

The reaction produced enough pressure to burst the bottles and cause a loud boom, the spokesman said.

Though they caused no injuries or serious property damage, the blasts caused frightened callers to jam 911 lines--250 calls were received in 90 seconds after a particularly forceful boom on Nov. 21.
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And it continues:

North Side: New mystery boom

BY JIM NOLAN
TIMES-DISPATCH STAFF WRITER

Dec 4, 2004

The booms have resumed.

Residents in the Bellevue neighborhood of Richmond's North Side were shaken and stirred yesterday by another mysterious boom.

The explosion was heard around 9:49 a.m. and prompted at least 35 calls to 911, said Richmond fire Lt. Keith Vida.

Reports placed the origin of the boom in the 1400 block of Wilmington Avenue.

Officials were unsure what caused the explosion. Vida said investigators searching the area were unable to find evidence of the household materials used in a number of the chemical-reaction explosive devices detonated in the area in the past month.

Two Ginter Park teenage boys have been arrested in connection with several of the explosions. Officials have said they are considering felony charges against four more suspects. Simply making or possessing the explosive devices is considered a crime.

To date, the booms have not injured people, nor have they caused serious damage to property. However, a number of homeowners in the area have reported cracks in their walls they attribute to the explosions.

Still, authorities are not convinced all of the booms can be accounted for by pranksters.

The city is expected to bring in special equipment over the next couple of days to help monitor the ground for possible seismic activity.

"We want to look above and below ground," Vida said. "We will continue the investigation."
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Boom, Boom, Boom

North Side disturbances continue, reports of booms in Manchester surface

Richmond News
Illustation Brannan Heywood/Richmond.com


Robb Crocker
Richmond.com
Friday December 3, 2004

For the second day in a row, the Richmond Police received more than 100 phone calls to complain about the now not-so mysterious booms that have plagued North Side since Nov. 2. According to the Richmond Police, the booms returned Friday at 9:30 a.m. Officials continue to say that they are investigating the disturbances but local residents have begun to become increasingly annoyed with the situation.

"From a neighborhood's perspective, when the booms first started, there was a great concern about the safety of homes and residents," 2nd District City Councilman William J. Pantele said Friday morning. "There was relief when the cause of the booms was identified.

"Now that we're getting more explosions, annoyance and irritation are the present mood. There is plenty of anger that this is continuing."

Like Thursday's disturbance, Friday's is believed to be centered near the Hermitage Road and Bellevue region of North Side.

Police have charged two teenage males, 14 and 15, with the felony of manufacturing, possessing, using, etc., of fire bombs or explosive materials or devices. The two youths appeared in court on Monday.

Pantele, who lives in the 3300 block of Suffolk Avenue of North Side, knows about the neighborhood anger first hand. He says has received well over 200 emails about the booms.

"My inbox has been overflowing," he said. He has also received phone calls and recently helped hold a public meeting that attracted over 400 North Side residents.

Pantele says he is not sure if the recent booms are the leftover devices from the two suspects or if there is a copy cat troublemaker.

Richmond.com received information from a Manchester resident that the region just across the James River has also been experiencing mysterious booms – as many as 15 since mid-October.

"I thought it was just me," said Dani Rodgers, who lives on the 200 block of West 14th Street. "One of my neighbors, who lives on Semmes Avenue, has also heard them."

Rodgers says she has recently reported the disturbances to the police.

"The booms have been less frequent over the past two weeks…There haven't been a lot of reports from here because this isn't a densely populated area. I first reported it because I was concerned that what I was hearing and feeling was what was occurring in the North Side.

"At first we didn't think to report it because there is so much construction going on Downtown."

Rodgers says the booms actually shake her home, much like last December's earthquake.

Bill Farrar, public relations manager for the City of Richmond Public Works Department says so far, his department has only received one report of booms in Manchester. He added that the events in North Side are the "only verified events that we know of."

City officials are treating the Thursday's and Friday's reports as "new event" according to Farrar.

"...it is difficult to say whether they are related," he said. "Richmond Fire, Police and Emergency Management Services continue to investigate this in a coordinated fashion.

"Nothing has been ruled out. Leftover devices are posible but unlikely."

Pantele says the possibility of a copy cat could come from sympathy or from the results of local media coverage. Most local outlets have described, in some detail, how the pressure building devices were designed (something that Pantele pointed out, could be just as easily be found on the Internet).

"These events are news but we have to be careful romanticizing and calling attention to these kinds of things," he said. "I hope that judgment would be exercised. These acts are usually done for attention or to get a thrill.

"I don't fault the media but I would urge for some circumspectness."

If there is a copy cat prankster out there, Pantele is urging that person to quit.

"This prank is a major problem," he explained. "It is extremely ill-advised and we're going to make it stop – one way or another.

"A certain amount of this is 'kids will be kids' and teenagers seeking a thrill that defies common sense. But there is a line that can get crossed and we're well past that line.

"When the public gets sufficiently tired of that activity, they're going to make it stop. If that's what it takes, that's what we'll do. It's in the best interest to stop it."

Although there has been an increased police presence in the North Side, Pantele says the city is still relying on citizens to report anything suspicious. Police officials are urging North Side residents not to call 911. If you hear a boom, city officials ask that you call the city’s non-emergency number at 646-5100.

Farrar says that city officials are not aware of any infrastructural damage in the sewer systems but they are continuing to investigate. He recommends that anyone who has noticed structural damage to their home to document it and contact their insurance company.
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Actually a side panel reveals those teenagers have been released:

Boom suspects released

Teens return home after hearing; police say 4 more suspected

BY JIM NOLAN
TIMES-DISPATCH STAFF WRITER

Nov 30, 2004


Reverberations from the series of North Side booms were still being felt yesterday - in court.

A bond hearing was held in Richmond Juvenile and Domestic Relations District Court for two teenage boys arrested late last week and charged with creating the homemade devices allegedly responsible for rattling nerves and windows during the past month.

The suspects, ages 15 and 14, spent the weekend in jail. The first teen was arrested Wednesday. Police said yesterday that they had arrested a second teen Friday.

Both alleged boom-makers waived their appearance in court yesterday, instead sending two lawyers to represent them - Craig S. Cooley and Henry L. Marsh III. At their request, Judge Clarence N. Jenkins Jr. closed the hearing to the public.

Sources said that during the brief hearing, the commonwealth's attorney's office waived the right to try the teens as adults on felony charges of manufacture, possession and use of firebombs or explosive materials or devices.

Instead, the boys will be tried on that charge in juvenile court on Jan. 6. If convicted, they could still face jail time but would serve any time in the Juvenile Justice Center.

At the end of the hearing, Jenkins released the teens to their parents and placed restrictions on their movements pending trial. Parents of both of the teens refused comment to reporters at the courthouse.

But the investigation into the North Side booms case is far from over.

Law-enforcement sources said authorities are still seeking four more teens in connection with the booms, which made frightened a neighborhood and mobilized city fire, police and public works departments into a costly, manpower-draining effort to solve a mystery.

Authorities also said they are not convinced the arrested, and suspected, teens can account for all of the explosions heard in the last few weeks. At least some investigators wonder whether some of the booms are small seismological events.

"There was an explosion [Nov. 21] that was much larger than the ones we were dealing with,' said one law-enforcement source, speaking on condition of anonymity. "They [the teens] were definitely a contributing factor, a part of it. The question is how much."

To date, none of the booms is believed to have caused any injury to people or physical damage to property.

Some graffiti in the neighborhood indicated sympathy for the suspects. "Free the Bellevue Boomers" read one spray-painted sign along a wall in a parking lot off MacArthur Ave.

But the devices inflicted emotional casualties on North Side, where both teens live. Word of their arrests yesterday brought a mixture of relief and regret from their immediate neighbors in Ginter Park.

"We're happy we know what it is - it was getting scary," said Rachel Downey, 36, a mother of three young boys. She lives just around the corner from one of the teen suspects, whose names are being withheld by The Times-Dispatch.

"But we're disappointed it was someone in our neighborhood. I feel very sorry for the parents," Downey added, calling it a "prank that got out of hand. It caused a lot of concern and panic."

Anne Thorn, who lives around the corner from the 15-year-old suspect, said, "This is the time for him to have a wakeup call. I don't think he needs to go into the penal system, but it's not fun and games."

A mile away, a relative of the 14-year-old suspect brusquely refused to comment on the case, citing attorney's orders.

"We have no comment on this case against our innocent children," she said.
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And over in MA:

Article Last Updated: Saturday, December 04, 2004 - 2:11:27 AM EST

BOOM! ... What the heck was that?

Mysterious blasts, flashes in the sky have Tyngsboro residents rattled

By ADAM C. HOLLAND, Sun Staff

TYNGSBORO Looking south from his home on Curtis Road Tuesday night, Chris Lyons saw the bright flash light up the clouds.

About three seconds later came the boom a deep thump that shook his entire house.

From Hudson, N.H., to the Chelmsford line, the eastern half of Tyngsboro has been rocked with well over a dozen of these mysterious, pulsating booms over the past five weeks, rattling both windows and nerves.

Lyons said he knows a thing or two about explosives. As a youngster, the engineer used to mess around with M-80s or fashion homemade explosives under proper adult supervision, of course out of black gunpowder and aluminum piping.

"Those are like sparklers compared to what is going on here," Lyons said. "If this were in a house, there would not be a board left. The house would be pulverized.

"Ten sticks of dynamite might not completely blow up a house," Lyons added. "But what happened that night ... I can't even describe it. For a guy who's not afraid of this stuff, my God, I felt very intimidated.

"All I could think of, to tell you the truth, was my son going to school the next day, and it was unsettling," Lyons said.

All reported incidents have occurred after dark, mostly between 7 and 9 p.m. Nearly all of them have been reported on Mondays and Tuesdays.

When the bangs were first heard in late October, police called the Federal Aviation Administration, thinking they might have been sonic booms from aircraft. They were not.

Residents didn't report the incidents at first, thinking they were related to demolition or construction projects that might be happening in the area. Blasting permits are only allowed during daytime hours, and none were issued during this time period.

Callers initially reported seeing bright flashes of light in the hills west of the Firehouse Restaurant & Lounge which is about a half-mile south of the Tyngsboro Bridge and to the east, near the banks of the Merrimack River. Most of the flashes were white, but other eyewitnesses have reported seeing orange and red flashes. One resident said she saw blue lightning-like streaks.

"I didn't think anything of it," said Jackie Baker, who lives down the road from the Firehouse Restaurant. "But then, when it shook the house... ."

On Nov. 1, police received dozens of calls reporting at least six incidents between about 7:30 and 9:30 p.m. The Lowell and Chelmsford police departments also investigated similar complaints stemming from the same incidents.

Tyngsboro patrol cars were even in the area during all of the bangs, but officers could not pinpoint their location. Riding on all-terrain vehicles the next day, other officers searched the expansive woods west of the Boston University Corporate Education Center campus, where some thought the blasts might have originated.

More booms were heard Nov. 2, Nov. 9, Nov. 23 and Nov. 30.

"It was very loud," said Henry Moulton, who lives on Lawrence Road, just south of the school complex on Norris Road. "Something like a bomb exploding in World War II."

"I thought it was in my back yard," said Moulton's wife, Yvette. "I thought maybe the swimming pool had blown up."

It took nearly 10 minutes for Henry Moulton to get through to the police dispatcher, whose telephone line was flooded with dozens of similar calls.

What is especially baffling is that, to date, no one has reported finding any evidence of explosions, such as burn marks, splintered wood or rock or other debris.

"There's got to be something, somewhere," said Ellen Lyons.

It would seem unlikely that the blasts are being caused by dynamite or more modern explosives. In the wake of 9-11, even blasting caps must be painstakingly accounted for, making it nearly impossible to misplace such materials without drawing attention from federal investigators. Some residents suspect the blasts could be homemade concoctions of fertilizer, chemicals or explosive gases.

"We definitely want to get to the bottom of this ... absolutely," said Selectman Kevin O'Connor.

Deputy Police Chief Richard Burrows said the police don't know what's causing the low-pitched booms and are looking for the public's help.

People who have seen the explosions or know who is responsible are asked to call the Tyngsboro Police Department, 978-649-7504.
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You do wonder why this isn't being deemed a potential national security threat?
 
Emperor said:
........

A similar sound rocked the Lowcountry in August 2003. No cause was ever found, though some opined that it could have been "Seneca Guns," a folk explanation used to describe unexplained booms dating back to the 18th-century.

Some theorize that so-called Seneca Guns could be caused by gases being released from the ocean floor or a sudden rush of cold air hitting the Gulf Stream.
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Requires (free) registration:
http://www.charleston.net/stories/092204/loc_22boom.shtml
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More on that:

Story last updated at 8:18 a.m. Monday, December 13, 2004

Mysterious booms have shattered stillness for hundreds of years

BY JASON HARDIN
Of The Post and Courier Staff

It was 1:30 in the afternoon. The skies were clear of storms. It was a typical summer day. Nothing unusual to report.

But Aug. 1, 2003, suddenly turned into a strange day for the Lowcountry.

SENECA GUNS

What are they? Loud, deep booming noises occasionally heard along parts of the East Coast.
What causes them?No one is certain. Theories include undersea disturbances, collisions of air masses, and electrical discharges.
How did they get their name? Apparently, from noises said to sound like artillery that have been heard around Seneca Lake in New York. Author James Fenimore Cooper mentioned the phenomenon in his short story “The Lake Gun.”
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A booming noise swept across the area, rattling windows and startling residents, including one Reynolds Pommering of Mount Pleasant.

Pommering, who had been surfing the Internet in his apartment, said he expected the worst: A plane crash; a terrible explosion; a terrorist attack.

"I jumped up from what I was doing and ran out the front door. I really thought something bad had happened," he said.

But there was nothing to see.

As suddenly as it had started, the noise had vanished. It left behind no trace of a cause.

That deep, resonating boom was only the most recent in a string of mystery noises that stretches back hundreds of years, perhaps beyond. No official record apparently exists, but it seems to occur at least every few years.

The pattern is the same each time.

Telephone calls pour in to various authorities, who have no answers.

Military officials say it wasn't a jet smashing through the sound barrier. Emergency officials report no explosions or similar catastrophes. Meteorologists say it's not thunder. Seismographs reveal no substantial seismic activity, let alone a sizable earthquake. There is a theory, however.

The noise -- and perhaps many others like it over the years -- was an example of Seneca Guns, a folk term given to unexplained noises frequently heard along the East Coast.

The Seneca Guns might be mysterious, but they are real, seismological and meteorological experts agree. They have been reported as far back as the 1700s. The name comes from Seneca Lake in New York, where unexplained booming noises have been heard for centuries. James Fenimore Cooper (author of "The Last of the Mohicans") wrote about the phenomenon in a short story more than 150 years ago.

More recently, the booms have been heard frequently along the coast of North Carolina, particularly around Wilmington.

While experts agree that some of the noises might be Seneca Guns, there is less agreement on what, exactly, a Seneca Gun is.

There are plenty of ideas, however. Some are outlandish, some simple. Some involve spaceships taking off from the bottom of the ocean. And some are really weird.

Tyler Clark, chief geologist for the North Carolina Geological Survey, has heard them all: Sonic booms from far off that carry over the oceans; methane gas explosions from dead material on the sea floor bubbling up to the surface; underground limestone formations collapsing as water tables drop from relentless human thirst; little earthquakes; meteorites; UFOs.

"I've heard all kinds of crazy things," Clark said. "The bottom line is that nobody's been able to come up with an explanation for it."

Many have speculated that seismic activity, perhaps small, localized tremors, might be causing the noises.

Clark discounts that idea. "The problem that we have is that earthquakes, contrary to popular belief, don't make a whole lot of noise," he said.

Earthquakes, except perhaps huge ones, don't really move air. Seneca Guns, however, seem to travel through the air, behaving more like sonic booms than underground tremors.

The undersea gases idea involves organic material gradually piling up at the bottom of the ocean. A pocket of gases forms and grows. Finally, something shakes it loose, and a bubble shoots to the top, creating a massive blast that some say is what swallows ships in the Bermuda Triangle.

Some suspect the noises have a clearly explainable cause; it's just that the military doesn't want us to know what it is. This theory has the noises coming from secret jets that can fly several times the speed of sound.

On the other hand, that doesn't explain why Seneca Guns were heard back in the days before the Wright brothers, let alone the Concorde.

Peter Malin, a Duke University professor of seismology, says he knows how to tell for sure where the noises are coming from. Put a recorder under the ground, then compare the readings to an above-ground recorder.

Malin says he's ready to do the work himself. There's a problem, however: Money for a recording device, or lack thereof.

"I need about $15,000," he said.

In any case, Malin says he's certain the sounds come from the atmosphere. He's heard them, and they rattle the windows, not the floor.

His guess as to the cause? A lightning-like electrical discharge that produces a thunderous noise with no visible lightning.

Richard Thacker, a senior forecaster with the National Weather Service, is skeptical of that theory. Seneca Guns can be heard on perfectly clear days.

"I can't perceive of how that could occur without some kind of cloud," he said.

Like other experts, Thacker has ideas. The booms could stem from the first wave of cooler air to hit the warm gulf stream air. He also mentions the underwater methane gas theory. Or they could be taking place at the same time.

Or, well, it could be something else.

"I think that this is going to be a harder one to pin down than the Loch Ness monster," said Thacker. "It really is truly kind of mysterious."

The hope is that someone will feel compelled to sit down and finally solve the mystery. That might take awhile, though.

The problem is that there's no great rush to figure out the cause of the Seneca Guns. They don't hurt anyone and don't disrupt commerce. Really, they don't do much other than make people curious.

"Maybe it is aliens," said Clark, not entirely seriously. "It defies all logical explanation at this point."
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"Boom" Mystery Solved?


(Allen County-WANE-December 23, 2004) - During the summer and early fall, dozens of Fort Wayne residents complained about loud "booms" that were rattling windows and shaking houses.

Theories on what caused them ranged from train cars colliding to a local scrap yard shredding used propane tanks. The mystery of what's causing them hasn't gone away, but this week, a Fort Wayne man told Newschannel 15 he has the answer.

This man didn't want to be identified, but gave Newschannel 15 a demonstration of detonating "black powder" in a home-made cannon. These demonstrations aired on Newschannel 15's 6 p.m show on Thursday, December 23.

"The more you use, the more you pack it, the louder it's going to be," he said.

Black powder is used as propellant for high powered rifles and available at your local sporting goods store. When it's packed tight and detonated with a wick, the resulting boom can be heard for blocks and shakes the ground.

The resulting boom violates the city noise ordinance, which is why he gave Newschannel 15 the demonstration in an open county field. The man said he knows a family who has a similar cannon that lives in the neighborhood right by Parkview hospital, where a lot of the complaints came from.

Sharon Churchward lives there and has heard the boom dozens of times. She was at the demonstration. "I'm glad I've heard this sound, because it kind of puts me at ease, because it's so close to what we've been hearing...if not exactly what we've been hearing," Churchward said.

A lot of people have pointed fingers at a shredder at Omnisource as the source of the noise...but Churchward said hearing the black powder blast convinced her otherwise. "This is what we've heard," she said. "it's not Omnisource. I really don't believe that."

The man says black powder isn't dangerous--people detonate it purely to make a loud noise.
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Funny how you don't think of mystery booms being deliberately set off by mystery persons, but it's quite a believable explanation, isn't it?
 
GNC said:
Funny how you don't think of mystery booms being deliberately set off by mystery persons, but it's quite a believable explanation, isn't it?
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Its one of many causes I'm sure and this shows up how weird it is as this is another mystery boom from Richmond that appears to be purely natural:

'Boom' registers seismic, barely

North Side Christmas Day rattles discovered by Va. Tech monitors

BY JIM NOLAN
TIMES-DISPATCH STAFF WRITER

Dec 29, 2004


The earth moved on Christmas day, but it had nothing to do with teenage pranksters.

Officials yesterday confirmed that the "boom" felt by residents in Laburnum Park early Saturday morning was a seismic event.

A very low-level seismic event.

It is called a "microseism," said Bill Farrar, spokesman for the Richmond's Office of Emergency Services.

"Something so low it doesn't even register on the Richter scale," he added.

That was the finding made by Virginia Tech engineers yesterday after examining readouts taken from three seismographs installed in the North Side earlier this month.

"Based on these findings and other factors, they believe the central Virginia region has been seismically active recently," Farrar said.

On Dec. 3, a weak earthquake measuring 2.2 on the Richter scale shook some Louisa and Goochland County residents. Residents in that quake reported hearing a boom that rattled some of their windows and dishes.

The North Side seismograph readouts were evaluated by engineers from Virginia Tech's Seismological Observatory in Blacksburg, which also operates the Earthquake Engineering Center for the southeastern United States.

Officials had the instruments placed in the Laburnum Park and Ginter Park neighborhoods several weeks ago, when the mysterious "booms" reported by residents continued even after the arrest of two North Side teenage boys in late November.

The teens were allegedly responsible for manufacturing and planting at least some of the "pressure producing" devices of soda bottles and household cleaners that sent booms rattling windows and nerves on the North Side for most of November.

But officials involved in the investigation were never completely sure that the alleged pranksters and several possible accomplices were responsible for all the shaking, rattling and rolling felt by the neighborhood.

Yesterday an alternative scenario presented itself. According to Farrar, however, officials said they have no way of determining the cause of the booms that occurred before the seismographs were installed.

A small seismic event should come as no surprise to Virginia residents.

Just over a year ago, an earthquake of 4.5 magnitude shook the same area of Goochland and Louisa counties, according to Martin Chapman, the head of Tech's Seismological Observatory, who reviewed the Northside seismograph results.

Back in 1897, Virginia Tech itself was rattled by a 6.0 quake centered nearby in Giles County.

In an online memo on seismic activity in the Southeast, the Earthquake Center's co-founder, James R. Martin Jr., said that recent studies "suggest that the southern Appalachian Highlands have the potential for even larger earthquakes than have occurred in the past."
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It seems quite likely that the arrested pranksters had nothing to do with the booms.
 
Seems like the case is proved for a natural explanation:

Experts bust the boom mystery

Scientist sleuths say noises were caused by 'micro-earthquakes'

BY MARK HOLMBERG
TIMES-DISPATCH STAFF WRITER

Jan 8, 2005


It now appears that it wasn't boys with "bottle bombs" that caused the big booms that mystified North Richmond during the past two months.

More likely, it was their mother.

Mother Earth, that is.

A series of "micro-earthquakes" probably produced the booms, said Martin C. Chapman, a seismologist and professor of geophysics at Virginia Tech.

"There are hundreds of them happening all the time in Virginia," Chapman told 60 North Side residents during a public hearing last night at Linwood Holton Elementary School. "The ground is always moving."

Now the city is buying is own earthquake-detecting equipment to avoid another long-troubling mystery. That equipment should be up and running in 90 days, said Ben Johnson, Richmond's emergency services coordinator.

Virginia Tech was called in last month to help unravel the mystery that began in earnest on election night and continued, off and on, through Christmas.

Compounding and - as it now appears - confusing the BOOMmystery were the arrests over the Thanksgiving holiday of two teenage boys who admitted to making a couple of small booming devices in late September and early October by mixing household chemicals in 20-ounce plastic bottles. That fueled speculation that the continuing booms were the work of young pranksters who became known as the "Bellevue Bombers."

Three seismographs installed in North Side last month by Virginia Tech's earthmoving experts detected a minus-1 magnitude tremor during the boom heard on Christmas Day. (Previous booms, many of them more pronounced, couldn't be measured because the nearest detecting equipment was in Fredericksburg and Charlottesville.)

That evidence, along with anecdotal information gathered from residents and some key comparative data from a 1986 quake in the same area, led Virginia Tech's sleuths to blame tiny shifts in the earth's crust less than a mile beneath the surface. While not conclusive, Chapman said, the quake theory is the most logical explanation.

During the past couple of months, Chapman told the crowd, it appears there has been a "series of these events happening in Richmond."

Why does that cause a boom? asked one resident.

Seismic waves created from rock sliding past rock radiate from the point of friction and convert to sound waves as they reach the earth's surface, Chapman said.

It typically makes a booming sound and sensation, he added, very similar to a truck rumbling by just outside your house.

That description caused roughly half of those present to nod in complete understanding.

Chapman explained that these micro-quakes tend to "flare up and die off," although they can sometimes precede a stronger tremor.

Usually, though, they're "just a nuisance," he said, which produced a ripple of sardonic laughter in the crowd.

Virginia Tech research assistant Jake Beale showed a mapping of a 1986 quake in North Side, which he said is almost identical to recent activity.

North Side resident Bill Britton recalled that'86 quake. "I was in bed . . . BOOM! My first thought was the furnace had exploded. Second thought, the Yankees were back."

He said the biggest of the recent booms reminded him of that quake.

Some residents clearly weren't ready to give up on the serial prankster theory.

But Capt. William "Mike" Martin with the Richmond Fire Department said the nature of the mystery booms and the type of bangs from bottle bombs didn't seem to match from the start of the investigation.

But once the two boys were arrested, the prankster theory "unfortunately took on a life of its own," Martin said.

"The slant in the media all along is the kids did [the booms]," complained one resident.

In that regard, Martin said, the boys "probably caught a bum rap. . . . The timing was horrible."

The two boys were convicted Thursday. They made and detonated bottle bombs well before the booms became an issue.

The boys and their parents cooperated fully from the start, Martin said.

"I have to praise the families involved and the juveniles involved," Martin said. "They stepped up to the plate."

Nearby resident Hampton Carver drew applause when he said the community now has to realize that the two boys had nothing to do with the booms. "We've got to be fair to these kids," he said.
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Seems like the pranksters didn't get away scot free though - it has possibly saved them blowing themselves up at some point:

Mysterious Boom Trial

Two teens must serve community service after being convicted of charges in connection with the mysterious booms that have been rocking Richmond's northside. The two teenagers, ages 14 and 15, were tried at Oliver Hill Court House on Thursday.

Richmond Fire Investigator Captain William Martin testified as an expert witness. He described what the two boys did as illegal and potentially dangerous, but the investigation turned up no indication that the bottle bombs, while producing a sound louder than a gunshot, were the cause of the house-shaking booms plaguing the neighborhood.

The judge took into account the fact that the boys have never been in trouble before, and did no real damage with their homemade explosive devices. She sentenced the teens to 40 hours of community service and entered them into the "Restore to Justice" program, which requires them to meet face-to-face with neighbors they disturbed in order to understand the gravity of the situation, and told them if they stay out of trouble for six months, the charges against them will be dropped.

Senator Henry Marsh, one of the teens' attorneys, says he thinks the sentence was fair.

There will be a public meeting tonight to discuss the northside booms. Councilman Bill Pantele will hold the forum.

Both Ben Johnson, the city's emergency management director, and officials from Virginia Tech will be answering residents' questions.

The meeting starts at 6:30pm in the Holton Elementary School Auditorium. That's located at 1600 West Laburnum Avenue.
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Source
 
(right place for this?)

a thunderbolt falls april 1901

a sudden thunderstorm over witney brought not only peals of thunder, vivid lightning flashes, torrents of rain and large hailstones, but a thunderbolt which fell close to new mill. its greatly alarmed those in and around the mill with its teriffic noise resembling the roar of cannon, and smashed serval mill windows. we hear of no further damage.

(taken from the book "edwardian witney 1901-10" by charles & joan gott)
 
Tuesday, March 8, 2005

Source of mystery booms likely to remain unknown

'Quiet' N.C. has no seismic-detection network

By Paul Garber
JOURNAL REPORTER

The mysterious booms that rocked much of downtown Saturday night may remain forever a mystery.

About 8:20 p.m., 911 dispatchers started getting a wave of calls reporting the booms, said Shawn Cline, the hazardous-materials coordinator for the Winston-Salem/Forsyth County Office of Emergency Management. The calls covered an area of downtown between Glade and Cherry streets, from Brookstown Avenue to the south and West 24th Street to the north, he said.

Cline said that he spent most of yesterday looking at whether a small earthquake or sonic boom might have caused the noise, but by the end of the day he didn't have a solid answer.

There may not be enough earthquake-measuring equipment in the area to determine whether a small earthquake occurred, said Tyler Clark, the chief geologist for the N.C. Geological Survey.

"This is likely to go down in the history books as a mystery," Clark said.

Saturday's booms were about the 10th such report he has had from the Winston-Salem area in the past five years, Clark said.

"These are not anything new," he said. "They've happened to our state for a long time."

There are more active fault lines in the states that border North Carolina then there are inside the state, he said.

"In North Carolina, we sit in the quiet zone," he said. Because of that, there is not a network of seismic equipment to track local earthquakes. It would be too expensive to track activity that almost never causes death or destruction here, he said.

It's also possible that the noise was a sonic boom, which is more likely to make the kind of explosive sound reported than an earthquake, Clark said.

But a sonic boom could not have come from a plane leaving or landing at Smith Reynolds Airport because the plane would be going too slow, said Dave Short, the air traffic manager at the airport.

Sonic booms occur when an airplane goes faster than the speed of sound.

Smith Reynolds air-traffic controllers do not track anything above its air space of 12,000 feet, Short said.

City public utilities officials considered the possibility that a methane explosion in a nearby sewer could have caused the booms but have ruled out that possibility.

"If an explosion had happened, there's got to be a release of pressure somewhere," said Ron Hargrove, the deputy director for the City-County Utilities Division. There have been no such reports, which would include such things as blown manhole covers or bubbles in toilet water.

Loud noises and vibrations that struck the Konnoak Hills neighborhood in 1994 turned out to be small earthquakes, the largest of which measured 1.7 on the Richter scale.
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http://tinyurl.com/e74af
 
A couple of years ago two jets made a sonic boom at once directly over my house. The house SWAYED from one side to the other, and I nearly fell out of the chair, it was like an alice in wonderland kind of experiance. It sounded like an explosion and I grabbed the chihuahuas(we only had two at the time so I was able to carry them) in case someone's house exploded and we would have to evacuate. It was godawful.
 
What's behind mysterious booms?


Phenomena produce theories, but no answers

By Alex Roth
UNION-TRIBUNE STAFF WRITER

April 23, 2006

Life can serve up a good mystery every once in a while. Weird things happen that defy explanation, that make us wonder how much we really know about the world.

Something of the sort happened in San Diego County shortly before 9 a.m. Tuesday, April 4, and so far no one has come forward with an explanation.

“My garage door is double steel and it weighs about 500 lbs. It was rattling back and forth like a leaf in the wind for about 3 or 4 seconds.”

– e-mail from University City resident on April 4 disturbance
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Whatever it was, it caused a woman's bed to shake in Lakeside. It created waves in a backyard pool in Carmel Valley. It set off car alarms in Kearny Mesa and rattled windows from Mission Beach to Poway to Vista. At various spots throughout the county, people reported a rumbling sound or a booming noise.

Scientists insist it wasn't an earthquake. The Federal Aviation Administration has no record of any planes producing a sonic boom by breaking the sound barrier.

Camp Pendleton officials say no activities on the Marine base could have created such a disturbance. There were no large explosions in San Diego County that day, and no meteor fireballs were reported in the sky that morning.

What was it, then?

Maybe it was the same thing that caused a strange disturbance in Mississippi on April 7, when the locals heard a loud boom that rattled windows all over Jackson County, throwing emergency workers “into a tizzy,” said Butch Loper, Jackson County's civil defense director. Authorities in that state still don't have a clue as to the cause.

Nor, to this day, can anyone explain what was behind similar episodes in Maine two months ago, or Alabama three months ago, or North Carolina four months ago. In each of those cases – as well as in other incidents around the nation over the years – residents reported hearing windows rattle and feeling floors shake even though no earthquake was detected.

There's almost certainly a simple, unromantic, “Aha!”-type explanation for each of these odd occurrences, something that everyone has overlooked for whatever combination of reasons.

But who knows?

Maybe we're not being told everything. Maybe the Earth still does things that present-day humanity doesn't understand.

The morning of April 4 was cloudy in San Diego County, with rain in some areas and temperatures in the low to mid-60s. In Lakeside, Judi Mitchell, an emergency medical technician who works the night shift at a hospital, had returned to her home on Lakeshore Drive and was just about to fall asleep. It was 9 a.m., give or take a few minutes.

Suddenly, the earth started to vibrate.

“The windows shook; my bed moved,” she said. “It moved my bookcase.”

The rattling lasted a few seconds. Mitchell, 44, has lived in East County all her life and considers herself an expert at judging the size of an earthquake. She quickly guessed this one was a 4.5 on the Richter scale.

But to the astonishment of everyone, a quake wasn't the culprit. Within hours, both the U.S. Geological Survey in Pasadena and the Scripps Institution of Oceanography in La Jolla issued statements saying no earthquake had been detected.

Last week, USGS spokeswoman Stephanie Hanna said the agency stands by its initial conclusion.

“No, it wasn't an earthquake,” she said. “We haven't changed our minds about that.”

By noon on the day of the incident, The San Diego Union-Tribune was being inundated with e-mails from people wondering what could have caused the strange tremors.

“My garage door is double steel and it weighs about 500 lbs.,” a man in University City wrote. “It was rattling back and forth like a leaf in the wind for about 3 or 4 seconds.”

A Mission Beach resident compared the sensation to “somewhere in between an explosion and an earthquake.” A woman in Carmel Valley noted that the rattling was very distressing to her cats.

In recent days, the Union-Tribune has tried to get to the bottom of this mystery. Our efforts haven't met with much success.

Was it a sonic boom? If so, it didn't come from any aircraft at Miramar Marine Corps Air Station, Maj. Jason Johnston said. And it didn't come from any Navy planes in San Diego, said Cmdr. Jack Hanzlik, a Coronado-based spokesman for the Naval Air Forces.

“There were no Navy aircraft operating in this area during that time capable of flying at transonic speed,” he said.

Officials with the California National Guard and several Air Force bases also insisted their planes weren't the culprit, as did a Colorado-based spokesman for the North American Aerospace Defense Command.

If a plane had been traveling over San Diego County at supersonic speeds, the Federal Aviation Administration would have picked it up on radar, said Cheryl Jones, the FAA's San Diego-based liaison to the Marine Corps.

Jones checked with FAA control centers in Palmdale and San Diego, which monitor 180,000 square miles covering Southern California, southern Nevada and western Arizona. The agency has no records of any plane, military or civilian, breaking the sound barrier on the morning of April 4, she said.

Under federal law, Jones added, the military can fly at supersonic speeds only in certain restricted areas, three of which exist in Southern California. One is 150 miles to the north of San Diego, the second is 220 miles to the east and the third is 27 miles off the coast. The odds of a plane in any of those areas creating a sonic boom that could be felt all over San Diego County are virtually nonexistent, she said.

Could some sort of rocket be the cause? A spokeswoman at Vandenberg Air Force Base, 60 miles north of Santa Barbara, said the base didn't launch any rockets that day. Neither did NASA, a spokesman for that agency said.

Was it a meteor? Unlikely, said Ed Beshore, a researcher at the University of Arizona's NASA-funded Catalina Sky Survey, which monitors asteroids and other heavenly objects.

Every few months, a meteor enters Earth's atmosphere and produces an “airburst” that can cause a disturbance on the ground, Beshore said. In one recent case, an airburst over the Mediterranean Sea broke the windows on a ship, he said. In the most extreme incident ever recorded, a 1908 airburst over Siberia flattened trees for thousands of miles.

But an airburst powerful enough to cause tremors all over San Diego County would have been noticed by scientists, Beshore said. And the American Meteor Society reported no fireball sightings over California on April 4.

A spokeswoman for Camp Pendleton scoffed at speculation that some sort of Marine mortar training exercise at the base might have caused the countywide rumbling. “It was not us,” 2nd Lt. Lori Miller stated flatly.

Miller was home in Vista on the morning of April 4 when her windows began to rattle. There is no possible way, she said, that a Pendleton training exercise could have caused a sensation like that.



Two months before the San Diego incident, Robert Higgins, the emergency management director of Somerset County, Maine, was confronted with a nearly identical set of puzzling circumstances. In February, panicked residents in a 15-mile radius reported feeling earthquakelike tremors. Authorities quickly ruled out an earthquake, explosion or industrial accident.

“I've called it the mystery of Somerset County,” Higgins said in a telephone interview last week. He still hasn't figured out the cause.

“I'm not done with it,” Higgins said. “I don't forget.”

Then there was the incident in Mobile, Ala., on Jan. 19, when residents in two counties reported hearing what sounded like an explosion and feeling “quakelike tremors,” according to news reports. To this day, no one is certain of the cause. By process of elimination, authorities have settled on the sonic-boom theory, even though no branch of the military has owned up to it.

There have been other similar unexplained events over the past few years. Something of the sort happened in Wilmington, N.C., on Dec. 20, 2005; Winston-Salem, N.C., on March 5, 2005; Charleston, S.C., on Aug. 1, 2003; and Pensacola, Fla., on Jan. 13, 2003.

“The large boom that shook walls and windows from Century to Milton on Monday remains a mystery, and probably will stay that way,” a reporter for the Pensacola News Journal wrote after the Jan. 13 episode.



On those occasions when a logical explanation is wanting, it's sometimes necessary to consult that archive of wisdom otherwise known as the Internet.

Among bloggers and Web-based conspiracy theorists, one of the leading explanations for the San Diego disturbance is that the military is testing a top-secret spy plane called the Aurora, which supposedly can travel several times the speed of sound.

“Sir, I've never even heard of that plane before,” an Air Force spokeswoman in Virginia responded when asked about the possibility.

Even UFO experts are baffled by what happened in San Diego. Asked whether a flying saucer might have caused such an event, Peter Davenport of the Seattle-based National UFO Reporting Center said, “Probably not.”

“UFOs almost never generate sonic booms or shock waves,” he added. “They accelerate so rapidly that they leave a vacuum in the sky, much the way lightning does.”

What happened in San Diego on April 4 seems destined to remain one of life's little mysteries, as inexplicable as those Bigfoot sightings in the Pacific Northwest.

Mitchell, the Lakeside hospital worker, remains convinced that an earthquake was the culprit, regardless of what the experts say. The tremors were too strong, she said, too violent to be anything else.

“The earth actually moved,” she said. “You could feel it. If it moved my bed, it moved the earth.”

If anyone out there has any answers, would you please be kind enough to share them with the rest of us? A lot of folks are really curious.
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www.signonsandiego.com/news/northcounty ... gboom.html
 
This last boom in on April 4 in San Diego was a really big one, being felt all over the county. San Diego county is huge, at almost 12,000 square kilometers - almost as big as the state of Connecticut.

The previous boom a few years back was eventually attributed to mortar practice at Camp Pendleton U. S. Marine base. San Diego County has several big military bases, including Camp Pendleton, Miramar Air Base (Top Gun), and Coronado Naval Base (huge ships, including Aircraft Carriers). So, the general local theory that these booms are caused by some kind of military activity is certainly reasonable.

Here's an article from the San Diego North County Times (NCTimes.com) about the April 4 boom:

NORTH COUNTY ---- A mysterious booming sound rocked the region Tuesday morning, causing a flurry of phone calls to authorities who couldn't explain the cause.

"It sounded like someone was dropping a 500-pound bomb," said Sgt. J.T. Faulkner at the Poway Sheriff's Station.

Officials said there was no definite evidence to link the blast about 8:55 a.m. to atmospheric conditions, earthquakes, sonic booms or explosions from artillery training at Camp Pendleton.


"We really don't have anything to confirm the cause," said Stephen Rea, emergency services coordinator for San Diego County's Office of Emergency Services. "There was no damage throughout the county."

The U.S. Geological Survey didn't register anything in the immediate area.

"We felt something shake our building," said Lt. Jim Bolwerk at the sheriff's communication center in Kearny Mesa, where dispatchers immediately fielded phone calls from concerned residents.

Cpl. K.T. Tran, spokesman for Camp Pendleton north of Oceanside, said he didn't feel any shaking in his building. The base started training at 6 a.m. with 81mm mortars that can sometimes be heard up to 50 miles away.

"I felt it at my home, University City," said forecaster Philip Gonsalves of the National Weather Service. "All that happened was that my windows rattled. There's a lot of speculation (about the cause), but that's all it is."
 
I found some interesting info on the "boom" phenom that goes on in australia, this is one link http://www.tmgnow.com/repository/secret ... skies.html
there are 5 parts,just click on "next" to get the other pages.
Google 'bright skies" and several other sources are found at the top few results,one of which is from nexus magazine.
I think it is a fascinating read myself.
 
recent mystery booms

not sure if this is the best place for this, but here it is.
there's been a string of recent "mystery booms," mostly in america from what i've been able to find. in each case, there were no earthquakes, no planes nearby capable of making a sonic boom, no reported meteor sightings, no explosions, accidents, crashes, or any particular explanation of the event. just a mysterious boom followed by some kind of shock wave. here's a(n unfortunately incomplete) list:
jan 17 - lincolnshire, england
jan ? - north carolina
feb ? - mobile, alabama
march ? - somerset county, maine
april 4 - san diego, california and las vegas, nevada
april 7 - missouri
april 12 - buffalo, new york
april 22 - san francisco and oakland, california
april 27 - lancaster, south carolina
the ones on april 22 were also accompanied by huge (approx. 2ft) chunks of ice falling from the sky. they were examined and found to be molecularly pure water, which is pretty unusual.
now, i know "mystery booms" happen, and i never took much interest in them before, but this string of them has me really curious. why so many? why so many in april? and why do they seem to be concentrated in the US? any ideas?
 
Do you have any references for these booms e.g. news sites etc.
Could be plane testing or some kind of flying practice (any of the areas look like a desert??) :D
 
I've also come across the booms and anomalous ice falls recently, I didn't realise they were linked, HAARP has just become fully operational and is capable of radiating 3.5 billion watts iirc, I had wondered if this had anything to do with the pure ice falls. 8)
 
GadaffiDuck said:
Do you have any references for these booms e.g. news sites etc.
Could be plane testing or some kind of flying practice (any of the areas look like a desert??) :D
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This article was part of the 'Breaking News' part of the FT site a few days ago...
 
Sorry - meant more in-depth references - I wanted to do a bit of nosing. Similar thing in regards to the police and poltergeist story.
 
most of the sources i found were just passing articles in local newspaper websites where they happened. i can dig some of them up again if you want.
im wondering, you think maybe it has something to do with that huge earthquake in russia a little while ago? maybe some kind of weird pressure releasing effect. wouldnt explain the ice chunks though....
hmmm.....
ill see if i cant find some good articles....
 
Have folk checked out today's breaking news there's a good item there 8)
 
Well as Mr Crunchy isn't posting that one:

Mystery disturbance traced to sound wave

Scripps scientists say it traveled over the ocean to desert
By Alex Roth
UNION-TRIBUNE STAFF WRITER

April 27, 2006

A group of local scientists has uncovered some clues to the source of a mysterious disturbance that rattled San Diego County on the morning of April 4, shaking windows, doors and bookcases from the coast to the mountains.

The scientists, based at Scripps Institution of Oceanography in La Jolla, say the disturbance was caused by a sound wave that started over the ocean and petered out over the Imperial County desert. Using data from more than two dozen seismometers, they traced its likely origin to a spot roughly 120 miles off the San Diego coast.

That spot is in the general vicinity of Warning Area 291, a huge swath of ocean used for military training exercises. The Navy operates a live-fire range on San Clemente Island, which is within Warning Area 291 and sits about 65 miles from Mission Bay.

The researchers also have charted dozens of similar, if less dramatic, incidents that seem to have originated in the same general area of the ocean. They aren't sure what caused any of them.

Peter Shearer, a Scripps professor involved in the research, has no idea whether the April 4 disturbance was natural or made by humans.

“I would guess it's either an explosion that somebody hasn't told us about or it could have been a meteor coming into the atmosphere,” he said. “But it was certainly a big disturbance in the atmosphere.”

Steve Fiebing, a Coronado-based Navy spokesman, said the live-fire range on San Clemente Island was inactive April 4. He also said there was no Navy or Marine Corps flight activity in Warning Area 291 on that day that would have caused a sonic boom or a countywide tremor.

The area, also known in military circles as Whiskey 291, covers 1 million square miles and is off-limits to civilian planes and ships, Fiebing said.

“There was no unusual training that would have caused anything close to what people here felt,” he said.

Cmdr. William Fenick, another local Navy spokesman, said no San Diego-based warships were conducting operations in Warning Area 291 that day.

“We don't know at this time where this earthquakelike sensation came from,” Fenick said.

The April 4 disturbance hit San Diego County shortly before 9 a.m. A quake was quickly eliminated as the cause, leaving a mystery that has been the source of three weeks of speculation from Pacific Beach to Lakeside to the Internet.

The Scripps researchers believe the disturbance was the result of a low-frequency wave that traveled through the air at the speed of sound as it moved from the ocean to the desert. It was picked up by more than two dozen seismometers in San Diego and eastern Riverside counties, the researchers said.

According to data analyzed by the scientists, the wave was felt on San Nicolas Island, northwest of San Clemente Island, at 8:40 a.m. It hit Solana Beach at 8:46 a.m., the western edge of the Cleveland National Forest at 8:47.30 and the eastern side of the Salton Sea at 8:53 a.m. From there, it appears to have dissipated.

Elizabeth Cochran, the lead researcher on the project, said the wave moved at 320 meters per second, roughly the speed that sound travels through the air. Its velocity was too slow to be that of an earthquake, she said.

Cochran, a postdoctoral researcher in the geophysics and planetary physics department, said the only explanation is that the wave was traveling through the atmosphere, not through the ground. At each location, the wave could be felt for roughly 10 seconds, she said.

Several months before the April 4 incident, the team had begun studying other nonquake disturbances that were registering on San Diego County seismometers, including 76 that apparently originated in that same general area of the ocean in 2003. Shearer said he and his colleagues figured that some of those disturbances surely must have come from offshore military exercises.

The researchers haven't been able to determine whether the April 4 wave was more powerful than the earlier ones or whether it simply felt that way because of atmospheric conditions.

If the disturbance was caused by the military, no one has owned up to it. The Navy and Marines say none of their planes were flying at supersonic speeds that morning.

“I'm told that a sonic boom would not cover that distance at all,” said Fiebing, the Navy spokesman.

The Navy uses Warning Area 291 for a wide range of training, including large-scale ship maneuvers and battle exercises, but Fiebing and Fenick said they were unaware of any such training April 4 that would have caused such a disturbance.

Authorities have said a meteor probably wasn't the cause because it would have been noticed by the scientific community. The American Meteor Society reported no fireball sightings over Southern California on that day.
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www.signonsandiego.com/news/metro/20060 ... 7boom.html
 
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