[link to www.thenewearth.org]
this might help u figure more out.its bout the earth not bein solid but having an "inner-earth". gravity is based in the crust not earth's center. therefore gravity would change where there is less depth to earth's shell. would explain why the water can do as u say. low-high spots. also i notce on your mAp several of the high points r EQ centers.