The importance of instrument location on barometric pressure-induced noise

Holger Steffen
Barometric pressure-induced noise in records of broadband seismometers, strainmeters and tiltmeters is one of the major limiting factors in analyzing the data for studies of the Earth's interior structure and properties. Even the instruments at the Black Forest Observatory (BFO), installed in a depth of 170 m in a mountain behind an airlock door, are influenced. We investigate the physical transfer mechanisms for pressure-induced noise with the help of a Finite Element model of the BFO,
more » ... of the BFO, emphasizing the effect of pressure changes on the horizontal components at different locations inside a vault, e. g. on piers and in niches. The results show noise amplification factors of up to 37 within a distance of 1 m, and changes in the direction of the measured components. Each component is influenced differently, which makes it difficult to determine the best location to place. In addition, former results can be confirmed and suggestions for a correction can be drawn.