Correction to: Nature Geoscience https://doi.org/10.1038/ngeo1020, published online 28 November 2010.

In the version of this article initially published, there was an error in the units listed in the Figure 1 caption. The last sentence should have read: “Real Earth topography is only a few kilometres high, which is very small in comparison to its ~6,371 km radius” instead of “...6,700 km”.