Design and test of Geophonino-3D: A low-cost three-component seismic noise recorder for the application of the H/V method

Abstract

Earthquake effects are strongly related with the properties of the local geology, amplifying the ground motion, especially in soft soils. This amplification is connected with the resonant frequency, which can be estimated applying the horizontal-to-vertical spectral ratio (H/V) method on seismic noise measurements. In this work, a low-cost user-friendly data acquisition system (Geophonino-3D) has been designed for three-component seismic noise recording. The developed system consists of the signal conditioning circuit and the Arduino Due with an SD Shield for data storage. The suitability of the equipment for the application of the H/V method has been first assessed in the laboratory, according to the experimental sensitivity, the internal noise stability and the channel consistency. Subsequently, experimental verification has been carried out by recording seismic noise at eight different sites along the province of Alicante (southeast Spain), with different soil characteristics. The performance of the developed acquisition system has been evaluated in terms of the power spectral density and the H/V peaks by comparison with the results obtained through a commercial seismic recorder. The obtained results show the applicability of the developed acquisition system to record seismic noise and to apply the H/V method. Geophonino-3D is an open source and open hardware system and the price of its components is much lower than any other commercial equipment, which becomes a significant advance especially for small research groups with reduced economic support.