[1] This paper presents a tomographic study on the S wave velocity structure of China and adjacent regions. Group velocity dispersions of fundamental Rayleigh waves along more than 4000 paths were determined with frequency-time analysis. The study region was divided into a 1°Â 1°grid, and velocities in between grid nodes were calculated by bilinear interpolation. The Occam's inversion scheme was adopted to invert for group velocity distributions. This method is robust and allows us to use a fine grid in model parameterization and thus helps to restore a more realistic velocity pattern. Checkerboard tests were carried out, and the lateral resolution was estimated to be 4°-6°in China and its eastern continental shelves. The resulting group velocity maps from 10 to 184 s showed good correlation with known geological and tectonic features. The pure path dispersion curves at each node were inverted for shear wave velocity structures. The threedimensional velocity model indicates thick lithospheres in the Yangtze and Tarim platforms and hot upper mantles in Baikal and western Mongolia, coastal area and continental shelves of eastern China, and Indochina and South China Sea regions. The Tibetan Plateau has a very thick crust with a low-velocity zone in its middle. Beneath the crust a north dipping high-velocity zone, mimicking a subducting plate, reaches to 200 km in depth and reaches to the Kunlun Mountains northward. In northern Tibet a low-velocity zone immediately below the Moho extends eastward then turns southward along the eastern edge of the plateau until it connects to the vast low-velocity area in Indochina and the South China Sea.INDEX TERMS: 7218 Seismology: Lithosphere and upper mantle; 7255 Seismology: Surface waves and free oscillations; 9320 Information Related to Geographic Region: Asia;

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regional digital networks, and portable broadband seismic networks deployed in Sichuan, Yunnan and Tibet, we obtained the SKS fast-wave direction and the delay time between fast and slow waves of each station by use of the stacking analysis method, and finally acquired the fine image of upper mantle anisotropy in the eastern Tibetan Plateau and its adjacent regions. We analyzed the crust-mantle coupling deformation on the basis of combining the GPS observation results and the upper mantle anisotropy distribution in the study area. The Yunnan region out of the plateau has different features of crust-mantle deformation from the inside plateau. There exists a lateral transitional zone of crust-mantle coupling in the eastern edge of the Tibetan Plateau, which is located in the region between 26° and 27°N in the west of Sichuan and Yunnan. To the south of transitional zone, the fast-wave direction is gradually turned from S60°-70°E in southwestern Yunnan to near EW in southeastern Yunnan. To the north of transitional zone in northwestern Yunnan and the south of western Sichuan, the fast-wave direction is nearly NS. From crust to upper mantle, the geophysical parameters (e.g. the crustal thickness, the Bouguer gravity anomaly, and tectonic stress direction) show the feature of lateral variation in the transitional zone, although the fault trend on the ground surface is inconsistent with the fast-wave direction. This transitional zone is close by the eastern Himalayan syntaxis, and it may play an important role in the plate boundary dynamics.upper mantle anisotropy, SKS wave, fast-wave direction, crust-mantle coupling, lithospheric deformation Since the 1990s, the broadband digital technology has made great progress in the research of the Earth sciences. The seismograms recorded by the broadband seismometers deployed in the world are widely applied to the study of seismology, deep structure and geodynamics. In this paper, we focus on the mantle anisotropy and related geodynamic issues. Generally speaking, the mantle anisotropy is determined by the lattice-preferred orientation of olivine crystals as a result of the mantle deformation. There are various causes resulting in the mantle deformation. Among them, the plate motion is a direct cause. The size and direction of the mantle anisotropy strongly depend on the velocity of the plate motion. In the various subjects of recent studies on geodynamics, the anisotropy in the mantle is one of effective ways to probe the complicated deep structure beneath the continent and its evolution, the crust-mantle coupling deformation, etc. [1,2] .

[1] We present a surface wave study aimed to resolve the azimuth-dependent propagation velocities of Rayleigh waves (10 -184s) in East Asia. The resultant anisotropy patterns demonstrate that East Asia consists of a number of tectonic domains, each displays a characteristic and selfconsistent deformation mode. The depth variation of the anisotropy pattern in each domain helps to understand the boundary actions on the lithosphere and the depth-varying deformation styles owing to rheology change.

The level of seismicity in Chanbaishan Tianchi Volcano has increased obviously since June of 2002. In this paper, the seismic activity of the Changbaishan Tianchi volcano is studied by using the data recorded at 15 broad‐band portable seismometers operating in the volcanic region in the summer of 2002. The result shows that the average rate of seismicity is more than 30 events per day in this area during summer of 2002. Most earthquakes occurred in two areas, southwest and northeast of the Tianchi caldera. The focal depths are shallow, and usually less than 5km. The b values of events occurred in southwest and northeast areas are quite different from each other. Seismic spectral and time spectral analyses show that the events occurred in the summer of 2002 are all volcano‐tectonic earthquakes. The obvious 2Hz low frequency component in seismic records at stations HSZ and DZD is mainly caused by local variations of media and low velocity fault zones near the two stations. We infer that the large number of earthquakes and earthquake swarms occurred in the summer of 2002 might be caused by local faulting induced by deep volcanic activities.