combination of filling underground caverns and instantly turned to steam which shot it high into the atmosphere separated out as hydrogen and oxygen. The sections that didn\'t separate would have remained as water and fallen back to the earth as rain, but depending on how much of the water was shot into the atmosphere, the pressure increases exponentially, which makes the fisher stronger, and shoots water taller. Because of it\'s extreme light weight it would have been dispersed on winds in the exosphere over a vast area. End result, the water came back down to the earth but scattered all over the place. It wouldn\'t simply fall back down and fill in the basin, and even if it did, it would slip into the crack and be underground.
As for the water that went underground, it would have instantly started cooling the magma below and turned it to hard rock the same way a volcano\'s lava hardens when it goes into the sea. Once this was cool enough to hold as solid rock, water would have started to fill the new lower basin and the fissure would have shut off. Man, that must have been cool to see.
From a distance. The water in the atmosphere would have been boiling hot when it feel on you as rain.