Wind and Sand Could Have Shaped the Great Sphinx of Giza

Did nature produce the basic form of the monumental sculpture in Egypt? A US research team found evidence for this theory in experiments.

Sphinx of Giza

In the Asterix volume “Asterix und Kleopatra” from 1965, the hefty Obelix is portrayed as the culprit behind the Great Sphinx of Giza losing its nose while he climbs on its head. The olfactory organ proved incapable of bearing his weight and eventually broke off. However, the historical record suggests that the monumental representation of a lion with a human head likely lost its nose only in the High Middle Ages. This challenges the modern myth that attributes the Sphinx’s missing nose to cannon fire from Napoleon’s troops during his Egyptian campaign in 1798.

In the 13th century, the Arab historian Abd al-Latif al-Baghdadi praised the splendid nose of the Sphinx. Still, by the late 14th century, it had already vanished. Another Arab author named Al-Maqrīzī reported that in 1378, a devout sheikh from a Sufi monastery in Cairo, known for his fanatic iconoclasm, struck off the Sphinx’s nose. He paid the ultimate price for his act, as an enraged crowd reportedly lynched him afterward.

Initially Painted Red

The construction date of the Sphinx, measuring 73 meters in length and 20 meters in height, is only approximately determined. Archaeologists speculate that it was built during the 4th Dynasty under the rule of Pharaoh Chephren (around 2520 to 2494 BCE) and was initially painted with reddish ochre. Its remarkable durability over four and a half millennia can be attributed, in part, to its location. The Sphinx was carved from a limestone outcrop, which also served as a quarry for the construction of the Cheops Pyramid. This placement in a gentle depression shielded its body from drifting sand for most of its existence.

The head of the Sphinx appears disproportionately small in comparison to its lengthy body, leading to various speculations. Some hypotheses suggest that the head was added later, but current research contradicts this notion. It is plausible, however, that the Sphinx originally had a larger head, and the present form may be a result of subsequent alterations. While this could explain why the head is less weathered than the body, concrete evidence supporting this theory has not been discovered thus far.

The flow experiments at New York University gradually peeled a shape out of half an ellipsoid.
The flow experiments at New York University gradually peeled a shape out of half an ellipsoid. Image: NYU/Applied Mathematics Laboratory.

Originally a Yardang?

Researchers have subjected another hypothesis regarding the origin of the Great Sphinx to scrutiny: wind and sand erosion may have naturally shaped the limestone mound into a lion-like form prior to any human intervention. The ancient Egyptians, around 2500 BCE, merely refined the nature-carved “prototype” to transform it into the iconic monument known today. The basis for this proposition is the existence of a geological feature called a Yardang, commonly found in deserts, as explained by a team led by Leif Ristroph from New York University.

To investigate this theory, the team crafted a small mound from soft clay with a denser material at its core, placing it in a water tunnel. A swiftly flowing stream of water aimed to simulate the wind erosion that had acted on the stone mound over millennia. The scientists chose a “semi-ellipsoid” as the initial form. Indeed, as the water eroded part of the clay, it left a shape closely resembling the basic structure of the Sphinx. The more resilient material became the “head” of the sculpture, and elements formed at the front in a similar manner resembled the neck and paws of the lion’s body.

The end result was a form that bore a strong resemblance to the Sphinx of Giza.
The end result was a form that bore a strong resemblance to the Sphinx of Giza. Image: NYU/Applied Mathematics Laboratory.

No Proof

The fact that the Sphinx is oriented in an east-west direction, aligning with the main wind direction, supports the lion-like formations created by erosion. However, the results do not constitute proof of the theory, acknowledges the team that recently published its findings in the journal ‘Physical Review Fluids.’

A featureless mound transforms to a majestic lion in repose. The cylindrical head is the only inclusion, and its “wind shadow” shields the body. Dye added to the clay helps to visualize the turbulent wake that carves the back of the lion. Releasing dye upstream reveals compressed streaklines under the head, and this accelerated flow digs the neck and reveals the forelimbs and paws,” says Ristroph. However, this only demonstrates that such a formation is possible. Whether it actually occurred remains open to question. In any case, there is ‘no doubt that the facial features and the detailed work were made by humans,’ according to Ristroph.