Underwater nuclear explosions

[CaptainChewbacca]

I was talking with Kodiak about this today, and I was wondering; How visible are underwater nuclear explosions? How far away are they felt?

Say you have a 1-megaton warhead sitting on the seafloor two kilometers down and it goes off, will you see a great blast of steam come out? Will there be waves? Or just miles of dead fish?

[Lord of the Abyss]

I googled, and found an article in Wikipedia, and found a bit about Operation WIGWAM which was 600 meters down, 30 kilotons. There's a picture of the resulting rather large eruption of water.

[Sea Skimmer]

You get an eruption of water like a depth charge if the nuke goes off deeply enough that the fireball cannot breach the surface. Nothing too special about it. If the fireball sort of breaches the surface then you get something like Test Baker, a huge spray cloud around a water column. The shear mass of water involved seems to pretty well mask the creation of any steam.

[Dark Flame]

http://www.acehtsunami.com/deep-underwa ... losion.php

An example of a deep underwater explosion is the WAHOO test, which was carried out in 1958 as part of Operation Hardtack. The nuclear device was detonated at a depth of 500 feet (150 m) in deep water. There was little evidence of a fireball. The spray dome rose to a height of 900 feet (270 m). Gas from the bubble broke through the spray dome to form jets which shot out in all directions and reached heights of up to 1700 feet (520 m). The base surge at its maximum size was 2½ miles (4 km) in diameter and 1000 feet (300 m) high.



The heights of surface waves generated by deep underwater explosions are greater because more energy is delivered to the water. Deep underwater explosions are thus particularly able to damage coastal areas, because surface waves increase in height as they move over shallow water, and can flood the land beyond the shoreline. Many of the theories and concepts about these waves are similar to those that are applicable to other types of surface waves, in particular, tsunamis, and waves generated by the fall of a meteor.



If a deep underwater explosion occurs at a sufficient depth, the rising gas bubble can overexpand because the gas pressure falls below the pressure of the surrounding water. This causes the bubble to collapse, which causes a second shock wave and bubble expansion. This may be repeated, though there are unlikely to be more than three expansions. An example is the WIGWAM test, which was carried out in 1955. The nuclear device was detonated at a depth of 2000 feet (600 m)

The link has a couple of cool pictures, too.