How did they film the nuke explosion in Broken Arrow?

Question

In the film Broken Arrow, a nuclear weapon is set off underground in an abandoned mine. Here is the scene: https://www.youtube.com/watch?v=gS56O-aHEMs I'm interested in two points in this clip: First at 0:33, you can see the ground sink as it falls into the mine shaft. (I'm not worried about the explosion - that looks like a typical petrol & explosives set up. It's the ground falling in that interests me.)Then at 0:55, you can see the ground rippling and moving as it comes up behind and under the Jeep.The first one looks quite realistic - as if they really did set off explosives underground.The second also looks realistic, but could be a miniature or CGI. Is there any information on how those effects were achieved? Did they actually set off a big underground explosion, or was it miniatures and standard small blasts?

Answer 1

It is unlikely that a large explosion was created, movies that do that (and there are) tend to be know. For example, in The Revenant you can see an avalanche in the background and that's a real one, triggered by dropping dynamite from a helicopter!

In this case, there's visual effects involved. You can see the image stretched optically in second 31-32 of the clip, and the ground opening seems to be VFX and maybe some of it painted. Smoke helps with obscuring any imperfections. Interestingly, the 55 seconds part may be partly real (no problem putting explosives to raise sand of the ground and there is no indication anyone is in that vehicle so no one in danger), but in the shot above at second 57 there is again VFX involved as you can see the far background out of focus (in a wide shot like this it would be in focus) so it is possible miniature.