On noise reduction in vertical seismic records below 2 mHz using local barometric pressure

Abstract

We propose a simple method for the reduction of noise in vertical seismic recordings at frequencies below 2 mHz. The method consists in subtracting the locally recorded, scaled, atmospheric pressure signal from the gravity record. The scale factor is frequency independent and can be linearly estimated from the data. While such a pressure correction was previously only used in the analysis of tidal records, it is equally efficient at the low‐frequency end of the normal mode band and we use gravity recordings of the big 1994 Shikotan and Bolivian quakes to demonstrate this point. Our examples also show that this correction permits to achieve noise levels well below the New Low Noise Model (NLNM) [Peterson, 1993]. The success of the correction also sheds some light on the physical processes responsible for the generation of low‐frequency seismic noise at quiet observatories.

Brief communication "Seismic and acoustic-gravity signals from the source of the 2004 Indian Ocean Tsunami"

“…However, Müller and Zürn (1983) observed a seismic signal caused by the about 10 times stronger atmospheric signal of the Mount St. Helens eruption at a station in Germany. Other reports of atmospheric pressure changes in relation to seismic recordings are discussed by Kanamori et al (1991), Zürn and Widmer (1995), Neumann and Zürn (1999) and Zürn et al (2005). Therefore, seismic stations closer to the tsunami source might have a chance to record seismic effects of the passing infrasound.…”

The Noise Model of the SEIS Seismometer of the InSight Mission to Mars

“…Also shown are the instrument level vertical and horizontal requirements (blue and dashed blue lines, respectively) and the system level vertical and horizontal requirements (solid red and dashed red, respectively). These simulations assume the baseline parameters including that the wind is coming exactly from a North-West direction noise on Earth has been studied as it becomes a significant long-period noise source at 1-10 mHz-see Warburton and Goodkind (1977)) and several studies like Widmer (1995) propose that pressure signals may be decorrelated from the low frequency seismic signal.…”

Improvement of broadband seismic station installations at the Observatoire de Grenoble (OSUG) seismic network

“…Moreover, the cables were attached to the ground to limit spread of vibrations to the sensors. We decided to take a particular care about broadband velocity sensor insulation considering their sensitivity to noise induced by thermal and barometric variations (see Zïrn and Widmer (1995), Beauduin et al (1996), Stutzmann et al (2000)). We detail in the Sect.…”