Seneca Guns and Skyquakes

by Brian Dunning
November 12, 2019

It comes as a sudden and jolting din, an explosive boom rumbling from the distance; sometimes faint, sometimes as jarring as if a cannon had just fired a block away. They're called the Seneca Guns, mystery booms with no apparent source, reported to have been heard round the world for hundreds of years. The name comes from their most famous site: Seneca Lake, the largest of the Finger Lakes in central New York state. Ever since people have been hearing them, they've been searching for the cause, and so far come up empty handed. Today we're going to look at what's known of the Seneca Guns, and see if Skeptoid's skeptical eye can write anything useful on this so-far blank page.

Similar phenomena are reported all around the world. In Bangladesh they call them the Barisal Guns; in Japan they are the uminari; in the Netherlands and Belgium they're called mistpoeffers; in Italy, the lagoni; in the Philippines, retumbos. In other locales, they're simply called skyquakes. They're also reported in Iran, Australia, Ireland, Scotland, and many sites along the United States' eastern coast, where they often seem to be coming from way offshore. But Seneca is their most storied realm, where they are also known as Lake Guns or Lake Drums. So for the purposes of this episode, I'm going to use the generic term Seneca Guns.

Their documented history goes all the way back to 1850, when author James Fenimore Cooper wrote of the Seneca Guns in a short piece called "The Lake Gun" published in the book The Parthenon. Although it was political satire, it did include a nonfictional account of the local legend of these mysterious sounds around Seneca Lake. Cooper gave the following description:

It is a sound resembling the explosion of a heavy piece of artillery, that can be accounted for by none of the known laws of nature. The report is deep, hollow, distant, and imposing... No satisfactory theory has ever been broached to explain these noises... The most that can be said is, that such sounds are heard, though at long intervals, and that no one as yet has succeeded in ascertaining their cause.

But Cooper's story was hardly where their history began. Native Americans in the region had always known about the Seneca Guns, since long before the arrival of Europeans, who brought guns and explosives and other sources of loud artificial noise. The natives had ancient oral traditions about the Guns and various tribes had their various legends to explain them. By the time Cooper wrote his little story, the Seneca Guns were already an old story to the natives.

Recordings of the Guns are hard to come by, as in any given location, they're actually quite rare and always unannounced. But here are three. The TV show Unexplained Files tracked down a guy who set out his laptop for several days and managed to get a pretty low-quality recording:

One YouTuber heard two that were so loud they set off car alarms in his neighborhood, so he ran outside and managed to get more:

Here's another recorded during a rainstorm:

Nothing in those recordings comes off as unexplainable; we can probably all think of several things each might be. But go back in time a few centuries and it seems progressively less likely that they are industrial or military in origin. A lot of people have put a lot of work into this, so now let's review a few of the most popular explanations.

Supersonic aircraft

A lot of these mystery booms have, over the years, turned out to be sonic booms. Throughout 1977 and 1978, some 600 Seneca Guns alarmed residents up and down the Eastern seaboard from South Carolina up to Canada. The Mitre Corporation was engaged to look into them, and was able to positively match 2/3 of the Guns to known sonic booms, mostly from the Concorde supersonic airliner which had just begun its transatlantic flights.

On a number of recent occasions, the US Navy denied its jets had caused mystery booms that had been popularly reported in the press, only to reverse themselves shortly thereafter when the pilots came forward. This happened off San Diego in 2012, and in South Carolina in 2019. So, clearly, sonic booms are responsible for some of the Seneca Guns since about 1950; and perhaps for the great majority of them. But that still leaves hundreds of years of Guns unexplained.

Gas releases from lakes

One popular explanation is that natural gas bubbles up from the depths of the lakes and erupts from the surface, thus generating the noises. Cooper's 1850 story even mentioned this:

Conjectures have been hazarded about chasms, and the escape of compressed air by the sudden admission of water; but all this is talking at random, and has probably no foundation in truth.

Although the region does have abundant natural gas reserves, there is no evidence that massive releases of gas have ever been observed to suddenly burst from the depths of Seneca or neighboring lakes, and no reason to think that if such a thing happened it would make a deafening cannon-like sound. In fact, no such events have ever been observed anywhere, so far as I could find. This suggestion seems to be little more than — as Cooper said — conjecture. And in science, you can't just make something up. Explaining one unknown with another unknown isn't a valid process.

Earthquakes

Many scientists have long suggested that small earthquakes could vibrate the ground in much the same way as a low-frequency stereo speaker, producing audio in the form of a low rumbling sound. This sound is called a brontide, which also refers to the low rumbling that follows a thunderclap. One seismologist, Dr. David Hill, has notably offered earthquake-associated brontides as a nomination for the cause of the Seneca Guns.

Many other seismologists have not been convinced. First of all, the Guns are not described as low rumbling sounds, but as sharp explosive reports. Second, Seneca Gun events have so far never correlated with local seismic events; and if earthquakes did make cannon-like reports, this would have been a well-known characteristic of them throughout history. Modern instruments are a lot more sensitive than humans, so it's not likely that this is happening and the seismographs just aren't picking it up.

So although earthquake-associated brontides are probably the most often cited explanation, they're not a very good one.

Atmospheric ducting & lightning

We talked about this in Skeptoid #526 on Sky Trumpets. Atmospheric ducting is when temperature layers in the atmosphere form a sort of tunnel that can, under certain conditions, transmit very loud noise over a very long distance. It's similar to the way a speaking tube on an old ship worked; talk into a pipe, and your voice comes out perfectly audible a very long distance away. Atmospheric ducting is real and not theoretical. Here is an audio recording from March 2011 of a loud rumble heard over a large area of Florida:

People freaked out as there was no evident source of the rumble, prompting the National Weather Service to issue the following alert:

THERE HAVE BEEN SEVERAL REPORTS OF VERY STRANGE SOUNDS FROM THE WOODVILLE AREA SINCE ABOUT 645 PM EST. THE NATIONAL WEATHER SERVICE BELIEVES THIS PHENOMENON IS BEING CAUSED BY THUNDER FROM DISTANT LIGHTNING STROKES… BOUNCING OFF A VERY STABLE LAYER ABOVE THE GROUND. THIS IS CALLED DUCTING… AND CAN ALLOW SOUND TO TRAVEL UNUSUALLY LONG DISTANCES.

The ducting tends to muddle the sound, which is why this came off as a rumble and not individually discernible thunderclaps. Could a single bolt of lightning produce a sharp report that would travel through a duct and be perceived far away as a Seneca Gun? So far as I was able to find, this has never been conclusively observed. It is certainly plausible, but it appears to be unproven that a ducted thunderclap could present as a single sharp report.

If this does happen, atmospheric ducting would be a good candidate explanation for the fact that Seneca Guns are both rare and usually reported in the same places all around the world, places which may be particularly prone to the specific atmospheric conditions needed for the phenomenon to take place.

Lots of different things

We've done a number of episodes similar to this one, where a strange phenomenon is reported over a long time by a lot of people. These include visual phenomena like ghost lights or so-called earthquake lights, audio phenomena like The Hum or Sky Trumpets, even off-the-wall fringe ideas like ball lightning. In many of these, we end up concluding that the great variety of reports were almost certainly caused by totally different things in every individual case. For Seneca Guns, these could include any or all of the explanations already discussed, plus things like mining explosives, meteor explosions, target shooters firing at Tannerite explosive targets, and who knows how many others.

Today, these explanations end up proving to be the solution for some Seneca Guns. However the stumbling block we encounter when suggesting "many different causes" is that the most probable of those causes are all manmade, and all the historical documents tell us that the Seneca Guns were known to the local indigenous populations before the arrival of Europeans, before those causes existed. So let's take a closer look at that stumbling block.

The Seneca Guns didn't really predate artificial sources

We're always told that the local Native Americans heard the Seneca Guns long before Europeans came to the area. This claim is repeated in nearly every book or article on the subject that I found. Turns out it's hard to support. As the Native Americans of the region did not have written language, there is no proof that anyone was hearing Seneca Guns before Europeans showed up with their firearms, which was in the mid 1500s. The hearing of distant firearms could easily have been the source of any oral traditions among the natives, which then had 300 years to permeate their cultural beliefs before Cooper wrote about it. Just because everyone says and everyone believes that the indigenous population was hearing the Guns before the arrival of Europeans — including the indigenous themselves — doesn't mean there's any proof. There isn't. What this means is that it's possible all Seneca Guns have some manmade cause, probably many different sources.

The solution?

This is a mystery which we're not going to solve today. We have useful candidate explanations that fit any given mystery boom, but in almost all cases, we're not able to prove it. Unproven does not mean unprovable. Any given boom is consistent with multiple possible explanations, and just because we cannot prove which one applies, it doesn't mean that the cause is unknowable or intractably mysterious.

Given the lack of proof that Seneca Guns were heard before the introduction of manmade causes, and given that phenomena like atmospheric ducting are real and not speculative, I'm satisfied that the Seneca Guns qualify as a fun puzzle but not as a true mystery. Keep in mind that whenever you read an article claiming that something relatively well known is an unsolved mystery, you should always be skeptical.

By Brian Dunning
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