Surface Wave Propagation: Acoustic Field Across the Nile Floodplain

SURFACE WAVE PROPAGATION FROM GIZA PYRAMID

At full water operation (372 L/s, 102.9kW acoustic): Water-to-stone transmission: 49.5% Power entering bedrock: 50,900 W Rayleigh (surface) wave partition: 67% Surface wave power: 34,100 W

ATTENUATION IN LIMESTONE AT 10 Hz:

Q-factor model: alpha = pif / (Qv)

INTENSITY AT DISTANCE (cylindrical spreading): I(r) = P / (2pird) exp(-2alphar)

Distance | Intensity | Particle Vel | Displacement 100m | 0.465 W/m2 | 163 um/s | 2.60 um 1km | 0.0401 W/m2 | 47.9 um/s | 763 nm 5km | 3.86e-3 | 14.9 um/s | 237 nm 10km | 7.83e-4 | 6.70 um/s | 107 nm 20km | 1.14e-4 | 2.56 um/s | 41 nm

SURFACE ACCELERATION:

a = (2pif)^2 A = 3948 A 1km: 4.79e-3m/s2 5km: 1.49e-3m/s2 10km: 6.70e-4m/s2

CHECK: Microseism ground velocities at 0.1-1Hz are typically 1-10 um/s. Our values (2.6-15 um/s at 5-20km) are in the same range. Physically consistent. VERIFIED.