This map shows the distance to the center of the Earth of the Earth's terrain both above and below sea-level.
The Earth is an oblate spheroid. Like a sphere, but its radius is larger at the equator than at the poles - by around 21 km.
Although this bulge is small compared to the size of the Earth, this difference is much larger than the scale of natural features. Everest is 8.8km from sea level, Challenger deep is 11km below sea level.
This means that high mountains closer to the equator are further from the centre of the Earth than Everest.
Gravity also varies across the Earth's suface,although this influence is smaller,+/- 0.1 km. Both of these are factored into the calculations.
The triangles show the maxima (in Ecuador and Peru, also Kilimanjaro in Tanzania) and minima (in the Artie ocean near the Gakkel Ridge )