The enclosure walls are still standing. The erosion is still readable. And after thirty-five years, the debate is still unresolved.
In 1991, Yale-trained geologist Robert Schoch examined the Great Sphinx of Giza and concluded that the erosion patterns on its enclosure walls were caused by prolonged rainfall-rainfall that, according to the climate record, ended thousands of years before the Sphinx was supposedly built. If Schoch is right, the Sphinx predates dynastic Egypt by millennia. If the conventional dating holds, the erosion must be explained by salt weathering, wet sand, pre-existing rock features, or some combination of mechanisms that no single geologist has yet unified into a complete account.
The Sphinx: The Water Erosion Evidence is the investigation neither side has written. Not a proponent's brief. Not a debunking. A geological investigation that presents both Schoch's evidence and the counter-arguments from Lehner, Gauri, Harrell, Christiansen, Reader, and Schneiker at full strength, attributed to the specific researchers who made them, with the evidence examined on its own terms.
The geological evidence: the undulating vertical profile on the enclosure walls. The differential subsurface weathering detected by seismic survey. The temple blocks showing erosion beneath Old Kingdom granite. The western intensification. The Dynasty XXVI tomb controls. The contrast with wind-eroded surfaces on the plateau above.
The counter-arguments: haloclastic salt weathering. Wet-sand deterioration. Pre-carving karst features. Continued Old Kingdom rainfall. A 2025 construction-process hypothesis that reinterprets the erosion as evidence of the building technique itself.
The paleoclimate record: the African Humid Period that makes the water erosion hypothesis physically possible. The Kuper-Kröpelin data showing rainfall may have continued at Giza until 2200 BC. The question of whether that rainfall was enough, for long enough, to carve what Schoch attributes to deep antiquity.
The tests that could settle it: OSL dating of the enclosure walls. Modern geophysical surveys. Excavation of the subsurface anomalies detected in 1991. None of these tests has been conducted, because access to the site has been restricted since the mid-1990s.
Five peer-reviewed publications form the scientific core of a debate that has generated thousands of pages of popular commentary. This investigation returns to the evidence.
Every factual claim sourced to peer-reviewed publications, verified research, and the scholarly record. Every geological observation attributed to the specific researcher who made it. Every counter-argument presented at full strength. No Atlantis. No ancient astronauts. No conspiracy theories about Egyptological coverups.
The evidence is the story. The geology speaks for itself.
