On 22/04/18 10:46, Mike S wrote:
On 4/21/2018 5:19 PM, wrote:
"Interesting. I remember reading that ocean water is higher near
underwater mountain tops due to increased gravitational attraction and
measurable from satellites,"

The would be one hell of a dense mountain to do that, I would think it
more likely to be because of a decreased gravitational pull being
forced away from the center of mass of the planet, due to its inverse
square relationship. But that is not my field of expertise. (is
anything ? the more I learn the less I know, if it weren't for
learning from mistakes I would be a babbling idiot - NO COMMENTS FROM
THE PEANUT GALLERY HERE !)

"I wonder if tanks could be designed with non-flat bottoms to
counteract what you mentioned"

Pretty sure that would not work because gravity is the leveling force.
As such the shape of the bottom should not matter.

Perhaps at a high altitude with a very large mass (dense, not
voluminous) placed under the center of the tank it could be
compensated. But then that makes splitting hairs look like hitting the
broad side of a barn with a planet.

I don't know the correct physics, just read a bit...

Satellite observations
The alternative is an indirect method that uses satellites fitted with
radar altimeters.
These spacecraft can infer the shape of the ocean bottom from the shape
of the water surface above.
Because water follows gravity, it is pulled into highs above the mass of
tall seamounts, and slumps into depressions over deep trenches.
http://www.bbc.com/news/science-environment-29465446

The Hidden Earth: Undersea Mountains by the Thousands
http://www.slate.com/blogs/bad_astro...satellite.html

Makes perfect sense to me. Consider, the material of
the mount must be more dense than water. If its
mechanical strength evaporated it would droop down
to form a level plain. So there's more mass between
the peak and the center of the earth, and more
between mean sea level and the center also. More mass,
more gravity. It'll pull the sea surface towards
itself.

Clifford Heath.