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您的检索式：作者名="Gaochun Wang"
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| 1 | High-resolution crustal velocity imaging using ambient noise recordings from a high-density seismic array:An example from the Shangrao section of the Xinjiang basin,China显示文摘A profile of shallow crustal velocity structure(1–2 km) may greatly enhance interpretation of the sedimentary environment and shallow tectonic deformation.Recent advances in surface wave tomography, using ambient noise data recorded with high-density seismic arrays, have improved the understanding of regional crustal structure. As the interest in detailed shallow crustal structure imaging has increased, dense seismic array methods have become increasingly efficient. This study used a high-density seismic array deployed in the Xinjiang basin in southeastern China, to record seismic data, which was then processed with the ambient noise tomography method. The high-density seismic array contained 203 short-period seismometers, spaced at short intervals(~ 400 m). The array collected continuous records of ambient noise for 32 days. Data preprocessing,cross correlation calculation, and Rayleigh surface wave phase-velocity dispersion curve extraction, yielded more than 16,000 Rayleigh surface wave phase-velocity dispersion curves, which were then analyzed using the direct-inversion method. Checkerboard tests indicate that the shear wave velocity is recovered in the study area, at depths of 0–1.4 km,with a lateral image resolution of ~ 400 m. Model test results show that the seismic array effectively images a 50 m thick slab at a depth of 0–300 m, a 150 m thick anomalous body at a depth of 300–600 m, and a 400 m thick anomalous body at a depth of 0.6–1.4 km. The shear wave velocity profile reveals features very similar to those detected by a deep seismic reflection profile across the study area. This demonstrates that analysis of shallow crustal velocity structure provides high-resolution imaging of crustal features.Thus, ambient noise tomography with a high-density seismic array may play an important role in imaging shallow crustal structure. | Gaochun Wang Xiaobo Tian Lianglei Guo Jiayong Yan Qingtian Lyu | 2018 | Earthquake Science2018，31，5： | 9 |
| 2 | The shallow Longmenshan crustal S-velocity structure of the fault zone using ambient noise tomography of a seismic dense array显示文摘The Longmenshan fault zone(LMSF),characterized by complex structures and strong seismicity,is located at the junction between the eastern margin of the Tibetan Plateau and the north-western Sichuan basin.Since the Wenchuan earthquake on May 12,2008,abundant studies of the formation mechanism of earthquakes along the LMSF were performed.In this study,a short-period dense seismic array deployed across the LMSF was applied by ambient noise tomography.Fifty-two 3-D seismic instruments were used for data acquisition for 26 days.We calculated the empirical Green's functions(EGFs)between different station-pairs and extracted 776 Rayleigh-wave dispersion curves between 2 and 7 s.And then,we used the direct-inversion method to obtain the fine shallow crustal S-wave velocity structure within 6 km depth in the middle section of the Longmenshan fault zone and nearby areas.Our results show that the sedimentary layer(>5 km)exists in the northwest margin of Sichuan Basin with a low S-wave velocity(~1.5-2.5 km/s)which is much thicker than that beneath the Longmenshan fault zone and the Songpan-Garze block.The high-velocity structures with clear boundaries below the middle of Longmenshan fault zone(~2-4 km)and the Songpan-Garze block(~4.5-6 km)probably reveal the NW-SE distribution patterns of both the Pengguan complex and the high-density belt hidden in the northwest of the Pengguan complex.And the obviously high-velocity anomalies observed at the depth of^1-2 km in the southeastern margin of the Songpan-Garze block can be considered as the Laojungou granites.Our results provide a high-resolution shallow velocity structure for detailed studies of the Longmenshan fault zone. | Dandan Li Gaochun Wang Ruihua Lin Kai Deng Xiaobo Tian | 2019 | Earthquake Science2019，32，5： | 3 |
| 3 | Indian plate blocked by the thickened Eurasian crust in the middle of the continental collision zone of southern Tibet显示文摘The relationship of the crustal contact between the Indian and Eurasian plates is a key issue in understanding crustal thickening and the subduction of the Indian lithosphere beneath the Qinghai-Tibetan Plateau. Across the middle of the Yarlung-Zangbo Suture(YZS), we deployed an ~450-km-long SN-trending wide-angle reflection/refraction profile to observe the P-wave velocity(vP) structure beneath the northern Himalaya and the southern plateau. Our results show that, 1. the high vP(~7.1 km/s) indicates that the Indian lower crust extends no more than 50 km north of the YZS. 2. The lower crust beneath the southern part of the plateau features an extremely low vP(<6.7 ± 0.2 km/s). 3. Compared with the velocities of several typical crustal lithologies in different temperature regimes, the low vPin the lower crust can be explained by felsic-intermediate granulite, which has prevented the lower crust from further eclogitization. We propose that the dip angle of the Indian lithospheric slab beneath the YZS is partly controlled by the composition of the lower crust of the plateau. In the northern middle YZS, the crust of the southern plateau is too thick and blocks the northward advancement of the Indian lower crust, resulting in the subduction of the Indian lithospheric slab into the upper mantle. The lower crust in western and eastern Lhasa is dominated by a mafic composition, and it was delaminated after eclogitization before the Miocene. The void zone generated by delamination favors the flattening and underthrusting of the Indian lower crust. | Gaochun Wang Xiaobo Tian Yibing Li Tao Xu Bo Wan Yi Chen Shitan Nie Xusong Yang Sicheng Zuo Jianli Zhang | 2023 | Earthquake Research Advances2023，3，3： | 0 |
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