Crust and uppermost mantle beneath the North China Craton, northeastern China, and the Sea of Japan from ambient noise tomography

Abstract

A 3‐D shear velocity model of the crust and uppermost mantle to a depth of 100 km is presented beneath the North China Craton (NCC), northeastern China, the Korean Peninsula, and the Sea of Japan. Ambient noise Rayleigh wave tomography is applied to data from more than 300 broadband seismic stations from Chinese provincial networks (CEArray), the Japanese F‐Net, and the IRIS Global Seismic Network. Continuous data from 2007 to 2009 are used to produce group and phase velocity maps from 8 s to 45 s periods. The model is motivated to constrain the distributed intraplate volcanism, crustal extension, cratonic rejuvenation, and lithospheric thinning that are hypothesized for the study region. Numerous robust features are observed that impose new constraints on the geometry of these processes, but discussion concentrates only on four. (1) The North‐South Gravity Lineament follows the ∼40 km contour in crustal thickness, and crustal thickness is anticorrelated with water depth beneath the Sea of Japan, consistent with crustal isostasy for a crust with laterally variable composition. (2) The lithosphere is thin (∼70 km) beneath the Songliao‐Bohai Graben but seismically fast. (3) Even thinner more attenuated lithosphere bounds three sides of the eastern NCC (in a horseshoe shape), identifying a region of particularly intense tectonothermal modification where lithospheric rejuvenation may have reached nearly to the base of the crust. (4) Low‐velocity anomalies reach upward (in a Y shape) in the mantle beneath the eastern and western borders of the Sea of Japan, extending well into continental East Asia in the west, and are separated by a ∼60 km thick lithosphere beneath the central Sea of Japan. This anomaly may reflect relatively shallow slab dehydration in the east and in the west may reflect deeper dehydration and convective circulation in the mantle wedge overlying the stagnant slab.

Methodology of Seismic Tomography

“…Many workers have used ambient-noise tomography to study shear-wave velocity structure of the crust and shallow mantle (e.g., Campillo and Paul 2003;Shapiro et al 2005;Lin et al 2008;Zheng et al 2011;Kao et al 2013). This method, however, requires a dense, modern seismic network.…”

Shear-wave velocity structure of the crust and uppermost mantle in the Shanxi rift zone

“…As suggested by previous studies, the rejuvenation of the North China Craton may be caused by the upwelling materials under the central North China Craton ; the Datong volcanic zone could be a result of this kind of tectonic movement. In order to make sure the reliability of the result, we also compare our result with that of Zheng et al (2011), and both results exhibit deep root low-velocity anomalies under the Datong volcanic zone.…”

Collaborative Research: High-Resolution Seismic Velocity and Attenuation Models of Western China

“…We can see that the Sn arrival time is around the center of the Sn window, which indicates the Sn velocity is approximately 4.45 km/s. In our study, we set an Sn velocity of 4.4 km/s based on the velocity model provided by Zheng et al (2011). The calculated Q 0 values were used to map the lateral variation of Q 0 by applying the LSQR algorithm (Figure 42).…”