by Alex Carter

In 2012 YouTube was inundated with videos of a very rare atmospheric phenomenon—the skyquake. Skyquakes are characterized by unexplained noises coming from the sky, often in remote areas with no obvious explanation as to the source of the sound. Skyquakes have been recorded all over the world, and in every case, the sky suddenly takes on a creepy hue and emits unsettling, unnatural noises.

The reason it’s easy to say that it was 2012 is because they were all uploaded to the same YouTube channel, skyquake2012, a channel that specialized in taking shaking, amateur phone footage and adding the creepy trumpet sound from Kevin Smith’s Red State movie. In other words, they were all hoaxes.

But the phenomenon itself is no hoax. A skyquake is a real event that has been documented for centuries.

It’s difficult to distinguish between fakes, videos of unexplained noises that are of human origin, and genuine skyquakes, but the real examples of this phenomenon are all described the same way by those who experience them: a loud boom that sounds like distant cannon fire. Weirdly, the genuine ones all occur near coastal areas.

No one has been able to fully explain why certain areas experience periodic skyquakes, but enough evidence exists to suggest these are real phenomena and that the residents of these areas aren't making up stories. The fact that there are words to describe the event in different languages lends further credibility. In Japan they are called uminari (海鳴り, "the rumbling of the sea"); in Dutch, "mistpoeffers"; and in parts of the U.S., "Seneca Guns."

Some skyquakes are said to have human origins, like when a military aircraft breaks the sound barrier—by the time the sonic boom is heard, the plane is no longer in sight. But that doesn’t explain any that were recorded before the invention of aircraft, which means there must be other explanations. One popular theory is that the sound is due to meteorites exploding in the upper atmosphere, although that raises the question as to why the bright flash accompanying the explosion isn’t more visible. Others suggest the noise may be due to thunder from storms over the horizon, which is plausible only if you don’t know what thunder sounds like.

The most likely explanation is that the Earth is passing gas. (Really!) The sound of gas escaping from underground vents would resemble a quiet volcano, or distant explosions, which would explain not only the sound, but why the sounds are pretty much only heard in coastal areas. Many of the vents weak enough to allow gas out would be underwater, and in many cases the gas may be due to decaying biomatter at the bottom of the lake. The gas could also be escaping from underwater caves that are collapsing.

All of this is to say, if you ever hear an unexplained explosion, rest assured that it was only the Earth. But for fun, you can still blame it on the dog.