A wide body of seismology research—ranging from HVSR (horizontal-to-vertical spectral ratio) methods to site-specific microtremor studies—maps the underground conditions that determine how vibrations travel. In the case of the antique Egyptian Khufu pyramid, t
The Khufu pyramid has survived millennia of heat, wind, and shifting sands. But the question scientists keep returning to is harder: when the ground itself starts moving, what exactly helps—or hurts—such an ancient structure.
The thread running through the research is not a single alarm or a new earthquake. It’s method: how engineers and geophysicists translate what they can measure at the surface into what’s happening in the ground beneath. And for historic monuments. that translation matters. because seismic risk is often rooted in bedrock depth. soil properties. and how structures interact with what’s under them.
Work on the Giza pyramids appears across foundational scholarship, including M. Lehner’s contextual approach to the Giza pyramids in Archiv. Fur. Orient. 32, 136–158 (1985), alongside M. Lehner’s The Complete Pyramids: Solving the Ancient Mysteries (Thames & Hudson, 1985) and M. Verner’s The Pyramids: The Mystery, Culture, and Science of Egypt’s Great Monuments (Grove Press, London, 2001). The construction and building material side is also anchored in D. Arnold’s Building in Egypt, Pharaonic Stone Masonry (Oxford University Press, ISBN 0–19–506350–3 (C2), 1991), and S. Hassan’s excavations work, including The great pyramid of Khufu and its mortuary chapel in Excavations at Giza, Season 1938–39, X. (1960).
From there. the research turns decisively toward seismic behavior and the instruments that can reveal the ground’s response before the next shaking arrives. R. M. Kebeasy and R. N. Albert investigated the seismo-tectonic nature of the Middle East region in Helwan Institute of Astronomy and Geophysics Bulletin no.126 (1976). Later work examines sustainability problems of the Giza pyramids, including S. Hemeda & A. Sonbol’s Sustainability problems of the Giza pyramids in Herit. Sci. 8, 8 (2020). For seismic behavior specifically, S. Desoky, K., Hendawy, H., I. published Historical Indications of Architectural Aspects Effect in Seismic Behavior in International Journal of Trend in Research and Development (IJTRD). ISSN: 2394–9333. 4 |(5) (2017).
Then comes the measurement backbone—microtremors, spectral ratios, and the effort to connect surface observations to subsurface structure. A. Noor, M. Kamruzzaman’s Microtremor measurements of two historical mosques in Bangladesh is documented from a conference held December 22–24. 2011. in Dhaka. Bangladesh (ISBN: 978–984–33–4363–5). Classic method foundations also appear: M. N. Toksoz & R. T. Lacoss on Microseism: Mode structure and sources in Science 159, 872–873 (1968), and O. Kulhanek’s Anatomy of seismograms (1990, Elsevier, Amsterdam; ISBN: 9780444883759, 9780444599964).
The key practical approach repeated across studies is the Nakamura technique and its descendants—especially HVSR, the horizontal-to-vertical spectral ratio. Y. Nakamura, E. D. Gurler, and J. Saita report Dynamic Characteristics of Leaning Tower of Pisa Using Microtremor-Preliminary Results in Proceedings of the 25th JSCE Earthquake Engineering Symposium. Tokyo. Japan. 29–31 July 1999 (2. 921–924). The broader method is explicitly traced through work such as Y. Nakamura’s Clear identification of fundamental idea of Nakamura’s technique and its applications in the 12th world conference on earthquake engineering (p.1–8) (2000). plus C. Lachet & P. Y. Bard’s Numerical and theoretical investigations on the possibilities and limitations of the Nakamura’s technique in J. Phys. Earth 42, 377–397 (1994).
The technique’s application logic is also documented in guidelines and practical tools. including the SESAME Project: Guidelines for the implementation of the H/V spectral ratio technique on ambient vibrations in Measurements. processing and interpretation (WP12. Deliverable N. D23.12) (2004). Further resources include Y. Nakamura’s On the HV spectrum in Proc. the 14th world conference on earthquake engineering (p.1–10) (2008) and Y. Nakamura’s Basic Structure of QTS (HVSR) and Examples of Applications, in Mucciarelli, M., Herak, M., Cassidy, J. (eds) Increasing Seismic Safety by Combining Engineering Technologies and Seismological Data NATO Science for Peace and Security Series C: Environmental Security (Springer. Dordrecht) (2009). with DOI: https://doi.org/10.1007/978-1-4020-9196-4_4_4.
But the research doesn’t treat HVSR as a magic answer. It runs into the messy details of what HVSR can—and cannot—tell you. Parolai. Richwalski. Milkereit. and Bormann assess the stability of H/V spectral ratios and compare them with earthquake data in the Cologne area in Tectonophysics 390. 57–73 (2004). Lermo and Chávez-García ask Are microtremors useful in site response evaluation?. in Bull. Seismol. Soc. Am. 84(5), 1350–1364 (1994). Arai & Tokimatsu explain S-Wave velocity profiling by inversion of microtremor H/V spectrum in Bull. Seismol. Soc. Am. 94(1), 53–63 (2004). Rong, M. et al. address amplitude discrepancy of HVSR and site amplification from strong-motion observations in Bull. Seismol. Soc. Am. 107(6). 2873–2884 (2017). and Albarello. Herak. Lunedei. Paolucci. and Tanzini simulate H/V spectral ratios of ambient vibrations through numerical model comparisons in Geophys. J. Int. 234(2), 870–878 (2023).
Across the broader region, site characterization studies keep building the case for why seismic resilience planning starts underground. Thabet uses site-specific relationships between bedrock depth and HVSR fundamental resonance frequency using KiK-NET data from Japan in Pure Appl. Geophys. 176, 4809–4831 (2019). Moustafa, Faried, and Yassien characterize Egyptian National Seismic Network station sites using genetic optimization for microtremor data inversion in J. Seismol. 28, 1445–1470 (2024). Yazdi. Motamed. and Anderson present automated methodologies for estimating site fundamental frequency and its uncertainty using horizontal-to-vertical spectral ratio curves in Seismol. Res. Lett. 93(3), 1721–1736 (2022).
Other Egypt-focused work expands the map of subsurface conditions through measurement. Kalil, E. E., A. E, H. H. & Mossa, H. evaluate the efficiency of horizontal to vertical spectral ratio technique for buried monuments delineation. case study Saqqara (Zoser) pyramid. Egypt. in Arab. J. Geosci. 9, 7 (2016). Maklad and colleagues profile shallow shear-wave velocity using microtremor arrays in the Nile Delta, Egypt in Eng. Geol. 357, 108346 (2025). Toni. Yokoi. and El Rayess carry out site characterization using passive seismic techniques in a case of Suez city. Egypt in J. Afr. Earth Sci. 156, 1–11 (2019). Maklad et al. use seismic ambient vibration array for site characterization in Ismailia, Egypt in Eng. Geol. 279, 105874 (2020).
The work also ties measurement choices to interpretation by bringing in data-processing and modeling tools. Herak describes Model HVSR—A Matlab® tool to model horizontal-to-vertical spectral ratio of ambient noise in Comput. Geosci. 34(11), 1514–1526 (2008) (ISSN 0098-3004). Field & Jacob theorize sedimentary layer responses to ambient seismic noise in Geophys. Res. Lett. 20, 2925–2928 (1993). Parolai and others focus on H/V stability. Gallipoli et al. link spectral ratios to structure and damage effects in Soil Dyn. Earthq. Eng. 24, 487–495 (2004), while Gallipoli’s approach sits alongside experimental and operational modal analysis work for other historic structures.
That’s where the wider seismic engineering literature shows how the same attention to dynamics can translate across heritage types. Sallam, M. A. et al. assess seismic vulnerability of historical minarets in Cairo in Geoenviron. Disasters. 10, 30 (2023). Altunişik et al. explore soil–structure interaction and earthquake input model effects on structural response of the Santa Maria Church and Guesthouse Building in J. Earthq. Eng. 27(14), 4094–4125 (2023). Coviello & Sabbà conduct a comprehensive experimental study on dynamic identification of historical three-arch masonry bridges using operational modal analysis in Appl. Sci. 15(19), 10577 (2025). Ai. Abdelrahman. and Eldosouky pursue Full-parametric. transdimensional. and joint inversion of surface wave dispersion and earthquake-based HVSR by MBMO for obtaining reliable subsurface structures in Sci. Rep. 16, 4312 (2026).
Even practical factors outside pure geology show up. Elbshbeshi et al. assess impact of water level fluctuations on Philae Island’s stability and seismic vulnerability using global positioning system and horizontal to vertical spectral ratio techniques in Results Eng. (2025). Mokhberi evaluates urban-area vulnerability using the H/V spectral ratio of microtremors in Int. J. Disaster Risk Reduct. 13, 369–374 (2015).
For the antique Egyptian Khufu pyramid specifically. the research framing—architectural and geotechnical aspects affecting earthquake resilience—lands on a simple but demanding reality: a monument’s endurance under seismic forces is not just about what’s built. but where it stands and how the soil and bedrock shape the shaking. Hassan’s description of the great pyramid of Khufu and its mortuary chapel. along with Arnold’s work on pharaonic stone masonry. provide the construction lens; studies on microtremors. HVSR reliability. bedrock depth relationships. and soil–structure interaction provide the earthquake lens.
The end result is not a guarantee. It’s a roadmap for resilience work: measure the microtremor signals. interpret the horizontal-to-vertical spectral ratio curves with awareness of limitations. connect those signals to subsurface structure and resonance frequency. and then use the findings to understand how an ancient stone monument like Khufu’s pyramid might respond when the ground begins to move.
And so the story of earthquake resilience for heritage doesn’t start with disaster. It starts with the quiet signals—captured at ground level—then translated into what the earth is doing beneath the stone.
Khufu pyramid earthquake resilience microtremor HVSR Nakamura technique site characterization geotechnical seismic vulnerability Giza pyramids