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| Crust and upper mantle structure beneath Bohai Sea inferred from receiver function study |
| Yinshuang Ai, Zhongyin Shen |
| Key Laboratory of the Earth’s Deep Interior, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China |
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Abstract We analyzed teleseismic waveforms recorded by 36 stations near Bohai Sea region and obtained 2 248 high quality receiver functions. The crustal thickness (H) and average crustal vP/vS ratio (κ) as well as the Poisson’s ratios beneath 34 stations were estimated using the H-κ stacking method. The results indicate that crustal thicknesses near the Liaoning province range from 30.0 to 35.5 km, and the corresponding vP/vS ratios vary from 1.72 to 1.89 which corresponds to Poisson’s ratio with a range from 0.243 to 0.305. We also apply a common conversion point (CCP) stacking method of receiver function (RF) to image the upper mantle discontinuity structure beneath Bohai Sea region. Both the 410-km and the 660-km discontinuities (hereafter called the 410 and the 660) show clearly in the study region. The transition zone (TZ) thickness shows a different picture from the west to the east of the study region, which is a little bit thicker than that of the global average in the west of longitude 122°E, however, thinner in the east of longitude 122°E. We suggested that the dehydration of sinking slab into the lower mantle or a small-scale mantle plume from the lower mantle generated hot upwelling beneath this region.
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Received: 01 September 2010
Published: 10 February 2011
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| Fund:the National Natural Science Foundation of China grants 40674028 and 40474022 |
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Corresponding Authors:
Yinshuang Ai
E-mail: ysai@iggcas.ac.cn
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