A new study by Egyptian geophysicist Asem Salama and colleagues has found that the Great Pyramid of Giza vibrates at natural frequencies of between 2.0 and 2.6 hertz — significantly higher than the surrounding soil's dominant frequency of around 0.6 hertz — a mismatch that reduces the risk of resonance, the potentially catastrophic amplification of shaking that occurs when a structure's rhythm matches that of the ground beneath it. The research, which placed sensors at 37 locations in and around the pyramid, also identified reduced vibrations near the internal relieving chambers above the King's Chamber, suggesting these structural features may help dissipate seismic energy. However, experts caution that the pyramid's longevity owes more to broadly sound empirical engineering — its wide base, low centre of mass, tapering form, and solid limestone foundation — than to any deliberate earthquake-proofing by its ancient builders, and that survivorship bias must be considered when drawing conclusions from monuments that happen still to be standing.