Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
a Width and depth of the Grand Canyon along the Bright Angel hiking trail from the south to the north rim (annotated in Supplementary Fig. 4). b Width and depth of Vallis Planck. The cross-section of Vallis Schrödinger is in Supplementary Fig. 6. Colors show 500 m elevation steps.