Bible flood - Science finds the water - Thanks Whereu

Thanks Whereu for triggering an interesting thought.
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Flood water came from skies and ground.
Gen 7:11.the same day were all the fountains of the great deep broken up, and the windows of heaven were opened.
Water covered highest mountain by 15 cubits (approx 7 meters)
Gen 7:20..Fifteen cubits upward did the waters prevail; and the mountains were covered.
Water then returned to the earth.
Gen 8:3 ..And the waters returned from off the earth continually: and after the end of the hundred and fifty days the waters were abated.
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Current surface water approx.....................1,386,000,000 cubic Km.
Extra water to cover Everest by 7 meter ...5,000,000,000 cubic Km
Current atmosphere water only...............................13,000 cubic Km
Underground water found by science.........4,150,000,000 cubic Km
https://www.wionews.com/science/gigantic-ocean-found-700km-below-earths-surface-706834
https://www.pbs.org/wgbh/nova/article/huge-underground-reservoir-holds-three-times-much-water-earths-oceans/