Gravity is often assumed to be constant across the entire planet, but because the Earth varies in shape and density, that's not really the case. Now, this super-accurate gravity map reveals that the fluctuations are even more extreme than scientists previously thought.
A team of scientists from Curtin University in Perth, Western Australia, rolled together data from satellite accelerometers and topographic studies to map the varying gravitational field between of over 80 per cent of Earth's land masses. That involved aamassing over three billion points with a resolution of around 250m. Crunching all the numbers would take a normal PC five seconds per point, but the team used a supercomputer to get it done in just three weeks.
While standard physics models suggest that gravity should vary between a minimum of 9.7803m/s squared at the equator and 9.8322m/s squared at the poles, the results from this new study disagree. In fact, they found that Mount Nevado Huascarán in Peru has the lowest gravitational acceleration -- at 9.7639m/s squared -- whereas the highest occurs at the surface of the Arctic Ocean, at 9.8337m/s squared. New Scientist takes an amusing look at the consequences of the findings:
[I]n the unlikely event that you found yourself falling from a height of 100 metres at each point, you would hit the surface in Peru about 16 milliseconds later than in the Arctic. You would also lose 1 per cent of your body weight in moving from the Arctic to the Peruvian mountaintop.