WORLD NEWS
The secret to the 4,500-year-old Great Pyramid’s ability to withstand earthquakes lies in the ground and shape rather than the stones.
A study was conducted using on-site vibration measurements and computer models to determine why the Great Pyramid of Giza, Egypt, is relatively strong against earthquakes.
This is not a proof that the pyramid is safe from all earthquakes, but rather a calculation of its response to specific shaking based on its current conditions and small ambient vibrations.
How did you measure the shaking?
The researchers placed sensors at 37 locations inside and outside the pyramid and recorded tiny vibrations created by wind, traffic and human activity. We found the natural frequency at which the structure naturally shakes and compared the way the ground and pyramid move together with a computer model.
What do the numbers mean
The main natural frequency of the pyramids was about 2.3 hertz, and the surrounding ground was about 0.6 hertz. If the vibration cycles of the ground and the building overlap, shaking can increase, but this means that the risk is relatively low here. Just because the numbers are different doesn’t mean they can withstand earthquakes of all directions and strengths.
What design helped?
The wide square base and tapering shape distribute the weight low and wide. A hard limestone base can reduce movement more than soft soil. Internal rooms and passages also change the path of force transmission, but this is not evidence of modern earthquake engineering calculations by ancient architects.
What’s still missing?
The study did not directly look at how joints between stones move during strong, real-world earthquakes. Information about cracks, past repairs and underground spaces is also limited. In large earthquakes or long-period tremors on very close faults, the response may be different.
Why study now?
Cultural heritage cannot be subjected to destructive testing, so it is important to find weak points through microscopic vibrations in the surrounding area. The same method can be used as a basis for prioritizing reinforcement work and monitoring future measurements for changes.
official source material
Scientific Reports original study