You can probably think up a few unsavory uses for an atomic bomb, but back in the ’60s, officials at Nevada’s National Security Site detonated a 104-kiloton nuclear explosion that had nothing to do with warfare. At the time, scientists were hard at work testing the feasibility of using nuclear weapons for aid in civilian tasks. The biggest one, of course, was mining – and there’s a reason for that. Ladies and gentlemen, behold: the subsidence crater.
The planet-melting sinkhole is the result of loose, dry soil compacting – in this case – after an underground explosion. In the video above, you’re actually watching two processes unfold. First, as the layers beneath the surface lose their stability, the upper layers of fine sediment collapse into the cavity formed by the blast. This downward “confining” is then followed by the reverse: an upwards-and-outwards plume of soil that’s generated as gas expands into the atmosphere.
It looks scary, but you might be surprised to find out that subsidence is actually a very natural phenomenon. The same thing happens when large amounts of groundwater are removed (or evaporate) from fine sediments, because that water is partly responsible for holding the ground up.
Subsidence in California due to groundwater removal. Source: USGS
And it doesn’t just happen here on Earth. Scientists have observed subsidence cratering on the Red Planet for years. The best example of this is Mars’ Hellas Basin, where fault lines cut through a large impact crater. Because the faults are younger than the crater itself, they likely formed as the sediments in the crater confined over time.
Source: ESA/DLR/FU Berlin
It looks jarring in the atomic test simply because the bomb’s energy causes the soil to destabilize much more quickly than we’d see in nature. You can see what’s happening a bit more clearly in this aerial view from a larger blast!