right we have an earth radius os 6300km, and assuming a water height of 5000m (about 3km
lower than everest) we get a total water volume of:
2.4*10^18 cubic metres. (that is alot, the volume of the oceans is estimated at about
1.3*10^18 cubic metres)
over a surface area of 4.8+10^14 square metres.
a total water height of 5000 metres over roughly 1000 hours (40 days) gives a water rise of
5m/hr... this is global remember.
so that gives a total outpour rate of about 2.4 * 10^15 cubic metres per hour globally.
okay, so let us say that this is belting out of what, 10,000 volcanoes like st helens at 10
square kilometres each. that gives us a total ourpouring rate per volcano of about
2.4*10^10 cubic metres per hour per volcano, or about 2.4*10^4 cubic metres of water per
hour per square metre of volcano.
that is alot of water, basically a 25km long column of pure water per hour. and we haven't
even evaporated it yet. lets do that next for fun to see how much energy it would require,
because I am enjoying this now.
we need 2.5*10^9 joules to boil 1 cubic metre of water, assuming the water is already at
100 degrees. over our entire volume of water, that is a total power of about 10^21 watts.
that is about 10^-6 of of the power of the sun, not bad, but we currently get only about
10^-15 of that energy, so it would require a brightening of the sun by about 10^11 times.
slap on some sunscreen.
of course it wouldn't all be boiled like this, I am just providing it as an example, since
all the water from st helens was in the form of vapour. but I could always do some pressure
calculations if you like to estimate the pressure at which the water must have been
jettisoned out. they will be big numbers though, and probably higher than the pressure
downwards due to gravity, which would mean that the water would be launched into space
(never hitting the earth and causing a flood) or just ripping the planet apart.
as you can see though, even with 10000 volcanoes of 10 square kilometers each erupting
nothing but liquid water for 40 solid days, you have a major problem on your hands, since
there is no evidence. I have not taken precipitation into account in this, but even if you
were to factor rain in, you aren't going to get rid of several orders of magnitude from the
volcanoes.
just to quote, some extreme rainfall records include nearly 1.2 m of rain in one day during
a typhoon at Baguio, Philippines; 0.3 m within one hour during a thunderstorm at Holt,
Missouri; and 0.063 m in over a 5-minute period at Portobelo, Panama. these are real
extremes, and you would need some really really odd weather to be able to maintain those
sorts of conditions for 40 days.
taking clouds to go up to about 20km (cumulo nimbus, or storm clouds extend up to about
50,000 feet) lets see what the conditions will be like if 50% of it were in the atmosphere,
and a mere 50% being jetissoned from our volcanoes etc
(only a 12 km long column per volcano now, phew.)
well say we have 1.2*10^18 m*3 of water in the air. that is about 1.2*10^21 kg of water
(water density 1000kg/cubic metre)
well the atmosphere is only about 5.3 x 10^18 kg so we would see a pressure increase of
about a thousandfold if all that water were dumped into the atmosphere..... assuming that
it could all exist as vapour (remembering that 1/4 of the atmosphere by volume up to the
cloud tops consists of water by this assumption) even stretching your distance up to 200 km
you are still faced with the same problem. you might be more likely to get away with it if
you streteched it out to 1000 km, but that is the upper limit on the thickness of the
earth's atmosphere! and you still get a thousandfold pressure increase.
