1) 700 km down is so far beyond our ability to drill (the deepest hole drilled to date is ~12 km), this water might as well be on the moon. At least we've been to the moon so far.
This.
__________________ Uncertainty is an uncomfortable position.
But certainty is an absurd one.
Drilling to the mantle is already planned... Just not 700km deep.
"If Japanese support can be combined with other funding, Teagle says they could start drilling before the end of the decade, making it possible for humans to finally reach the Earth's mantle by the early 2020s."