A climatology of infrasound detections in northern Norway at the experimental ARCI array

Läslo Gerardus Evers (1, 2) , Johannes Schweitzer (3)

1 Seismology and Acoustics [De Bilt]
2 Acoustic Remote Sensing Group [Delft]
3 NORSAR

The study of infrasound is experiencing a renaissance in recent years since it was chosen as a verification technique for the Comprehensive Nuclear-Test-Ban Treaty. Currently, 60 infrasound arrays are being installed to monitor the atmosphere for nuclear tests as part of the International Monitoring System (IMS). The number of non-IMS arrays also increases worldwide. The experimental ARCES infrasound array (ARCI) is an example of such an initiative. The detectability of infrasound differs for each array and is a function of the array location and configuration, the state of the atmosphere, and the presence of natural and anthropogenic sources. In this study, a year of infrasound data is analyzed as recorded by ARCI. Contributions of the atmosphere and the sources are evaluated in both a low- (0.1-1.0 Hz) and high-frequency (1.0-7.0 Hz) pass-band. The enormous number of detections in the low-frequency band is explained in terms of the stratospheric wind and ocean wave activity and compared with the detection of microseism. Understanding the detectability in the low-frequency band is of utmost importance for successfully applying infrasound as a verification technique since small-sized nuclear test will show up in this frequency range.

Mots clés: Infrasound; Array; Signal detection; Source identification; Acoustic propagation

Domaines: Sciences de la Terre

Läslo Gerardus Evers, Johannes Schweitzer. A climatology of infrasound detections in northern Norway at the experimental ARCI array. Journal of Seismology, 2011, 15 (3), pp.473-486. ⟨10.1007/s10950-011-9237-8⟩. ⟨hal-00687350⟩