October 2002
Columns
What's new in exploration
The baffle of the bulge. For the past 18,000 years, our planet has been slimming. Now, it’s suddenly starting to bulge in the middle. Researchers are baffled. While there are explanations for slight changes in the Earth’s dimensions, none of them account for a shift this big, this fast.
The first satellites showed that Earth is rather pear-shaped, and because it is spinning and made largely of somewhat elastic rock, it is a bit wider around the equator. The difference is slight – Earth’s equator is only about 0.3% greater than its height.
