Hidden Undersea Mountains...

[Rockhopper]

Satellites images show huge mountains under the sea!

The satellite altimeters worked by bouncing a radar signal or laser off the surface of the ocean being targeted and measuring how long it took the signal to return. That time can reveal the dips and peaks, or topography, of the ocean surface to within centimeters, scientists say. The sea-surface topography roughly mirrors changes in Earth's gravity. For instance, if an underwater volcano or mountain were hidden along the seafloor, the structure would push up against the sea surface and cause it to bulge. A trench, on the other hand, would cause the surface to sag.

Source

Tim.