signals/periphery
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SIGNAL
NODE 575 / 640 WIKI

Thomas Dobecki

NODE
575 / 640
TAGS
3
CITED BY
3 NODES
LANG
EN

American geophysicist who ran the 1991 Sphinx Seismic Survey with Robert Schoch and is first author on the resulting paper, “Seismic Investigations in the Vicinity of the Great Sphinx of Giza, Egypt”, in Geoarchaeology 7(6), 1992.

What the survey was

Four refraction lines around the body of the Great Sphinx, a five-kilogram sledgehammer on a steel plate as the source and twenty-four geophones as receivers, all four lines laid on the same limestone member that floors the enclosure. The result that mattered was an asymmetry nobody expected: the weathered layer runs 1.8 to 2.5 metres deep on the north, south and east sides and about 1 to 1.2 metres behind the rump. The same survey found a rectangular low-velocity anomaly under the left paw and a buried cliff east of the Sphinx Temple.

Why the name should be on the node

The survey is the only instrumented measurement in the entire Sphinx dating dispute, and it is a geophysicist’s work rather than a geologist’s or an author’s. The dating conversion built on top of it is Schoch’s and carries assumptions Dobecki’s data do not; keeping the measurement and the interpretation under different names makes that distinction visible.

Connections

1991 Sphinx Seismic Survey · Robert Schoch · Great Sphinx · Origins of the Sphinx · Sphinx Water Erosion Hypothesis · Colin Reader · Mark Lehner

RECORDED 7 Sep 2026 · LAST EDITED 7 Sep 2026

This entry records what the sources linked or listed above say, as of its last edit. It is not updated in real time. Errors go to the Corrections page; the Terms set out the limits of accuracy.