Underwater nuclear tests

[Enola_Straight]

In old WWII combat newsreels I often see what happens during a torpedo or depth charge detonation…on the water’s surface, that is.

At the moment of detonation, an area of surface water above froths due to the bang, then a geyser of spray and smoke erupt from the explosion below.

I’ve also seen the bang-froth with deepwater nuke shots
(the Baker test http://images.google.com/images?hl=en&q=baker%20underwater%20nuclear%20test&sa=N&tab=wi was a shallow water test)WITHOUT the resultant eruption of smoke geyser.

Why not?

[Valgard]

Nothing to burn? Seriously - the explosion occurs underwater and it’s not a chemical reaction, so the only stuff that can burn and produce smoke is fish, bits of seaweed, the bomb casing and whatnot. Compared to the volume of water that gets blasted all over the sky and the amount of steam produced, wouldn’t any actual smoke be background noise, so to speak?

[Fear_Itself]

Relative to the power of a nuclear explosion, Baker was detonated in very shallow water, only 90 feet or so. Here is a detailed description of the formation of the cloud above the surface:

Beginning 4 milliseconds after the explosion, the shock wave reaching the surface throws up a “spray dome”, rising at an initial speed of 2500 ft/sec (mach 2.5), in advance of the rapidly expanding bubble of hot gases. This picture shows the spray dome development a few milliseconds later. The light from the sub-surface fireball is clearly visible.

Once the fireball bubble (consisting of water vapor and bomb debris) reaches the surface a huge hollow column of water is thrown up, with the intensely radioactive gas in the bubble being vented through the center of the column.

The low pressure rarefaction zone behind the advancing shock wave causes water droplets to condense out of the moisture laden tropical air producing the “Wilson Cloud Chamber” effect.

A true deepwater detonation would be Wigwam which occured at a depth of 2000 feet, producing a shock wave dome followed by two large eruptions.

[Fear_Itself]

Here is a better series of photos depicting the initial explosion of Wigwam.

[Enola_Straight]

@Valgard

Nothing to burn? Seriously - the explosion occurs underwater and it’s not a chemical reaction, so the only stuff that can burn and produce smoke is fish, bits of seaweed, the bomb casing and whatnot. Compared to the volume of water that gets blasted all over the sky and the amount of steam produced, wouldn’t any actual smoke be background noise, so to speak?

Bombs ranging in size from briefcases to SUVs produce fireballs a mile in diameter or more. Does the cold and pressure of deep water completely re-absorb that fireball?

[bonzer]

@Enola Straight

Bombs ranging in size from briefcases to SUVs produce fireballs a mile in diameter or more. Does the cold and pressure of deep water completely re-absorb that fireball?

Pretty much. Even though the Baker test was shallow, the fireball itself probably never reached the surface.
But then Baker was only quite a small bomb as far as these things go. At 21 kilotonnes, it was merely comparable to those detonated at Trinity, Hiroshima and Nagasaki the year before.

[Bosda_Di_Chi_of_Tricor]

Of course, there are OTHER CONSEQUENCES to those deep-water detonations.