SFW:
http://www.yourdailymedia.com/media/1229523303/
Stumble Upon found this, and the site has no explanation, just the movie. What the hell was that? It looked like an amazingly powerful munition – the far shore fairly exploded, then the entire lake seemed to rush toward the camera. ?
I can’t see the link; it’s blocked at work. However, due to its incompressibility and density, explosive shocks are much stronger in water than they are in air. If you can give more details I can try to research it for you.
Looks a lot like what you’ll see if you search “depth charge” on YouTube.
There’s not a whole lot more detail. The video shows what appears to be a small lake, from the point of view of a fixed camera sitting on rocks on the shore. In the distance is a barren, rocky shore, with some pines or scrub visible further away. At about 6s, a huge explosion happens; the dirt on the whole of far shore is blasted into the air (or perhaps this is soil from the lake bottom, unclear), and it appears that all the water in the lake leaps many feet into the air. A ginormous wave comes directly toward the camera and engulfs it at 14s, finishing with black video. That’s pretty much it.
If you search “bomb lake” on YouTube, the same video is found here: http://www.youtube.com/watch?v=K9pm0CbIgeM&feature=related The YouTube commenters have the usual amount of relevant info (none).
Hard to tell anything without further info on scale. I could see 1000lb or even 500lb bomb doing that to reasonably small lake without problem.
It doesn’t look like the bomb is in the lake, to me.
It looks like they were removing a section of shoreline, and the lake just happened to be in the way.
Yeah, they should have picked a shoreline that didn’t border water. :smack: 
My thoughts, exactly!
I agree. It’s not a single explosion, but a string of charges that are exploded from left to right. The same as is done in a quarry.
You could remove large bits of the shore of Lake Missoula without disrupting much water.
Right. This is typical of a fair-sized intentional blast.
That’s my thoughts, too. It looked like relatively small charges; we’re just used to seeing the waves propagate through the air, and not through the water.