***But, if measured from the center of Earth to its peak, the highest mountain on Earth is actually some other mountain somewhere along the equator.***
Mauna Loa Hawaii.
If you took mt Everest, cut it off at sea level, and dropped it into the Marianas Trench, it would still have a mile of water over it.
Re: Mauna Loa Hawaii.
The big island of Hawaii is the tallest mountain on Earth from base to peak. Obviously, most of it lies under water.
The highest point on Earth, if measured from the center of earth, is not the top of Mt Everest, but rather the peak of that other mountain I mentioned above, located somewhere along the equator. Again, it’s the highest point due to the mountain’s location at the equator, where the earth has a larger radius from center to surface due to the equatorial bulge described above.