Shihao Yuan, Felix Bernauer, Joachim Wassermann, Eileen Martin, Heiner Igel

This study investigates the use of six-component (6C) seismic measurements for tracking moving traffic sources. We employ a collocated seismometer and rotational sensor to simultaneously capture both translational and rotational ground motions induced by vehicle sources. Our research demonstrates a novel method for determining source directionality using a single 6C station. This station has a small footprint, but it also allows us to extract directional information from both Rayleigh and Love waves. To validate our approach, we compare the estimated source directionality obtained from two different types of rotational sensors. Additionally, we compare our results against those derived from conventional array methods, including frequency-wavenumber analysis and array-derived rotation from a traditional seismic array deployed alongside our 6C stations. Our findings confirm the efficacy of the proposed 6C method in accurately locating vehicle sources. Importantly, the proposed 6C point measurement offers advantages over traditional array-based methods, particularly in environments where deploying multiple sensors is challenging. The success of this technique in traffic monitoring underscores its potential for broader applications, including real-time seismic source monitoring and early warning systems for geohazards. This study thus presents a significant advancement in seismic source tracking methodology, offering new possibilities for both urban and environmental seismic noise analysis.