Imaging shallow structure with active-source surface wave signal recorded by distributed acoustic sensing arrays

作者：Zhenghong Song,Xiangfang Zeng,Clifford H.Thurber,Hebert F.Wang,Dante Fratta

摘要：Distributed acoustic sensing(DAS) is one recently developed seismic acquisition technique that is based on fiber-optic sensing. DAS provides dense spatial spacing that is useful to image shallow structure with surface waves.To test the feasibility of DAS in shallow structure imaging,the PoroTomo team conducted a DAS experiment with the vibroseis truck T-Rex in Brady’s Hot Springs, Nevada, USA.The Rayleigh waves excited by the vertical mode of the vibroseis truck were analyzed with the Multichannel Analysis of Surface Waves(MASW) method. Phase velocities between5 and 20 Hz were successfully extracted for one segment of cable and were employed to build a shear-wave velocity model for the top 50 meters. The dispersion curves obtained with DAS agree well with the ones extracted from co-located geophones data and from the passive source Noise Correlation Functions(NCF). Comparing to the co-located geophone array, the higher sensor density that DAS arrays provides help reducing aliasing in dispersion analysis, and separating different surface wave modes. This study demonstrates the feasibility and advantage of DAS in imaging shallow structure with surface waves.

發文機構：School of Earth and Space Sciences State Key Laboratory of Geodesy and Earth’s Dynamics Department of Geoscience Geological Engineering

關鍵詞：DISTRIBUTEDACOUSTICSENSINGsurfacewavemultiplechannelanalysisSHALLOWSTRUCTURE

分類號： P631.4[天文地球—地質礦產勘探][天文地球—地質學]