This study presents the results of the Rayleigh wave group velocity tomography in North
China performed using ambient seismic noise observed at 190 broadband and 10 very broadband
stations of the North China Seismic Array. All available vertical component time-series
for the 14 months between 2007 January and 2008 February are cross-correlated to obtain
empirical Rayleigh wave Green’s functions that are subsequently processed, with the multiple
filter method, to isolate the group velocity dispersion curves of the fundamental mode of the
Rayleigh wave. Tomographic maps, with a grid spacing of 0.25◦ × 0.25◦, are computed at
periods of 4.5, 12, 20 and 28 s. The maps at short periods reveal lateral heterogeneity in the
crust of North China, in good agreement with known geological and tectonic features. The
North China Basin is imaged as a broad low velocity area, while the Taihangshan and Yanshan
uplifts and Ordos block are imaged as high velocity zones, and the Quaternary intermountain
basins show up as small low-velocity anomalies. A well-defined low velocity zone in the
Beijing–Tianjin–Tangshan region is observed at 28 s period. The low velocity zone may be
associated with the upwelling of hot mantle material. The group velocity maps at 4.5, 12 and
20 s are consistent with Bouguer gravity anomalies measured in the area of the Taihangshan
fault, that cuts through the lower crust at least.
