In P or compressional waves, the vibration of the rock is in the direction of propagation. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves.

Seismic station TV.SF11. Podere del Sole, Abbadia San Salvatore (SI)

"Real-time Structural Vibration Monitoring System using ESP32 and MPU6050. This project analyzes seismic data (PGA and MMI) for structural health assessment and provides early warning alerts."