Corrected Tilt Calculation for Atmospheric Pressure-Induced Seismic Noise

Abstract

In a literature search on the coupling of wind-generated pressure fluctuations into seismic noise, it was noticed that the expression for the angular tilt induced by pressure fluctuations in the seminal paper “A preliminary investigation into the relationship between long-period seismic noise and local fluctuations in the atmospheric pressure” by G. G. Sorrells was only valid at the surface. A search of the literature which cites the Sorrells paper was performed to see if any subsequent research corrected this error, and what effect the error might have on the research. A recent paper by Tanimoto and Wang notes the correct expression for the tilt, but employs the simpler erroneous expression in the research. In this paper, we develop the correct expression for effective measured displacements and approximate expressions analogous to those of Sorrells. The resulting magnitudes and decay with depth are then displayed and compared to Sorrells. Next, the results of the literature search are discussed. The results of three papers are identified as potentially modified by the correction of the tilt calculation. Finally, it is noted that the majority of the papers referenced are not affected by the correction, since many of the papers are for near-surface displacements of very low frequencies.

Keywords

• tilt
• wind-noise
• seismic
• horizontal component