Red Herring Steamed

If we play this number game, water at temperature below $80^oC$ (density $971.8\,kgm^{-3}$) but above $60^oC$ (density $983.2\,kgm^{-3}$) has a density of $975.96\,kgm^{-3}$ which gives,

$v_{boom\,ice}=3.4354*\cfrac{975.96}{2*1+1*8}=335.28\,ms^{-1}$

which would be lightning speed, quoted at $750\,miles\,per\,hour$.  Was magnetite a red herring?  Earthquakes is due to lightning strikes on condensed underground steam?

How much energy can be released when lightning strikes condensed water at the above temperature range ($\approx75^oC$ from www.engineeringtoolbox.com)?