Geoid measurements aren't a measurement of what the earth's surface actually looks like, but what it looks like mathematically through gravitational measurement

Geoid measurements aren't a measurement of what the earth's surface actually looks like, but what it looks like mathematically through gravitational measurements. Because the Earth's uneven distribution of mass, the object never looks like a sphere (although to be clear, the Earth is actually oblate spheroid -- it's like someone sat on a ball just a little bit, and that ball is bulging at its sides). Additional reading if you're interested: http://en.wikipedia.org/wiki/Figure_of_the_Earth#Geoid http://en.wikipedia.org/wiki/Figure_of_the_Earth#Geoid http://en.wikipedia.org/wiki/Geoid http://en.wikipedia.org/wiki/Geoid