Seismic surveys for an oil and gas company?
I was wondering about a meteorite, too, thinking about the one that went over Russia. If the meteorite was higher up, it wouldn’t have caused damage, but we could have still heard a boom.
They showed a seismograph on the news today - it definitely registered on the seismograph, but still nobody knows what it was.
How would seismic create such a significant booming sound?
I vote for ice/frost quake. I’ve heard of them before and think we are experiencing the right conditions.
On Friday, December 17, 1976, I was working with a carpenter in Lawndale, California, in the early everning and we heard a loud but distant boom. Kurt was not as startled as I was although he was a World War II veteran. As it turned out, it was the S. S. Sansinena, which blew up and broke in half in San Pedro (Los Angeles) Harbor.
Seismic surveys use explosions to bounce sound waves off geologic strata to geophones, which can then report to computers. The computers can construct a model of what’s underground, and indicate where digging for oil, gas, whatever, should occur.
An icequake is possible too, given the temps we’ve had in Alberta lately.
An asteroid zipped past Earth yesterday afternoon–only 350,000 km away! Just sayin’, is all, y’know.
There’s another one coming Sunday night, so be prepared.
Sunday? But I have plans for this summer! And the rest of my life!
That other town is a boom town.
On the bright side, you’ll know what the boom was. For a split second.
Now you’ll learn to fear the fury of my wrath! :mad:
Update: It looks like ice quake is all but confirmed. I knew intellectually that they were loud, but damn! That was LOUD! We heard it clearly a couple of kilometers away.
I know what seismic is, I work in oil and gas, and am, in fact, working on a microseismic program right now. 
I was being leading - seismic is low energy and, unless something goes wrong, doesn’t create a noticeable effect above ground. That said, I suppose something does go wrong once is a while, which is probably why this was suggested as a cause.
Anyhow, glad they solved the puzzle! I’ve heard ice cracks that sound like gunshots (while on the ice, yikes!), but it’s interesting this can happen on solid ground.
Some ideas:
[ol]
[li]Someone detonating explosives, illegally[/li][li]An airborne meteor explosion (already addressed)[/li][li]An underground cavern or mine collapsing. No one has yet to discover the mine or cavern in question.[/li][li]Top secret military flight caused sonic boom[/li][/ol]