Controlling the aeolian erosion of the Great Sphinx

Abstract

The body of the Great Sphinx has suffered severe weathering, exfoliation and wind erosion; the face is not reached by coarse granules and is well preserved. The body lies below the level of the desert, and the excavated area that surrounds the Sphinx constitutes a low-pass filter for the size of the sand grains. In past millennia, when the Sphinx was immersed in the floating sand dunes, severe wind erosion was caused by the coarse quartz granules that advance by saltation in the first metre above the variable sand level. Clearing out the excavated area has proved to be an effective preservation technique.