Preliminary study of lateral variation in crustal structure of Northeast China from teleseismic receiver functions

We conducted comprehensive receiver function analyses for a large amount of high-quality broadband teleseismic waveforms data recorded at 19 China National Digital Seismic Network (CNDSN) stations deployed in Northeast China.An advanced H-κ domain search method was adopted to accurately estimate the crustal thickness and vP/vS ratio.The crust has an average thickness of about 34.4 km.The thinnest crust occurs in the central region of Northeast China,while the thickest crust is beneath the Yanshan belt.The v P /v S ratio is relatively uniform with an average of about 1.733.The highest vP/vS ratio is found beneath the Changbaishan,likely associated with its volcanic activities.We found significant lateral heterogeneity beneath three stations CN2,MDJ,and MIH located along the Suolon suture from the back-zimuthal dependence of Moho depth.The velocity modeling from receiver functions indicated complicated Earth structure beneath these stations with large crust-mantle transition zone,noticeable velocity jump in upper mantle,and low velocity zone in middle crust.Dipping velocity interface in the crust with strike approximately parallel to the Suolon suture and down-dip to the south or southeast might explain the observed lateral heterogeneity.