Papers

2024

1. Deep structure and dynamics under East Asia

   Jianshe Lei, Xiaobo Tian, O.P. Mishra, and 1 more author

   Journal of Asian Earth Sciences, Jan 2024

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   In East Asia there are abundant active faults, strong earthquakes, and active volcanoes, such as the Tanlu fault zone, the 1668 Tancheng earthquake (M 8.5), the 2008 Wenchuan earthquake (M 8.0), and the active Chang­ baishan intraplate volcano. This special issue includes 16 papers, most of which focus on the big mantle wedge structures and dynamics under eastern China and eastern Tibet using seismic and magnetotelluric data recorded by dense arrays. Some researchers investigate the structures under southern Tibet and southern China. These results could be of great significance to understand the deep structure and dynamics of active volcanoes and strong earthquakes under East Asia.

2023

1. 全球下地幔波速异常结构综述

   石宇通,  叶蔚然,  宾可轶, and 2 more authors

   地球与行星物理论评, Nov 2023
2. Seismic anisotropy and geodynamics of the East Japan subduction zone

   Dapeng Zhao, Jian Wang, Zhouchuan Huang, and 2 more authors

   Journal of Geodynamics, Jun 2023

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   Seismic anisotropy in the East Japan arc has been extensively investigated by conducting shear-wave splitting measurements, receiver-function analyses, and tomographic inversions of body-wave travel times and surfacewave dispersion data, which have provided a wealth of information on dynamic processes associated with active subduction of the Pacific plate. Measuring shear-wave splitting is popular and effective to detect seismic anisotropy, but it has poor depth resolution. This problem has been overcome by conducting 3-D anisotropic tomography, which has high-resolution in both lateral and vertical directions. Both P and S wave anisotropies are revealed in the crust, which are caused by alignment or preferred orientation of crustal minerals and stressinduced microcracks related to active faults. Trench-normal fast-velocity directions (FVDs) of azimuthal anisotropy are revealed in the back-arc mantle wedge, reflecting subduction-driven convection there. Trenchparallel FVDs appear in the forearc mantle wedge under the land area, which may reflect deformation that re­ sults in B-type olivine fabric. The forearc mantle wedge offshore may lack anisotropy, suggesting that it is stagnant and decoupled from the subducting slab and does not participate in the viscous flow, in sharp contrast with the rest of the mantle wedge. The most significant findings of the body-wave anisotropic tomography are its constraints on the slab anisotropy. The subducting Pacific slab exhibits mainly trench-parallel FVDs, which reflect shape-preferred orientation of crystals and cracks related to normal faults produced in the outer-rise area before the plate subduction, overprinting the fossil anisotropy that the Pacific plate gained when it was produced at the mid-ocean ridge. Trench-parallel intraslab fast velocity planes of anisotropy intersect the slab upper surface at high angles (~45–90◦), reflecting aligned hydrated faults in the slab. Ruptures of the hydrated faults in the upper part of the slab may cause large intraslab earthquakes (M ≥7.0) that take place frequently beneath the forearc area. Trench-normal FVDs also appear in the subslab mantle, which may reflect asthenospheric shear deformation associated with the overlying slab subduction.

3. Insight into seismotectonics of the central-south Tanlu Fault in East China from P-wave tomography

   Yejun Sun, Haibo Wang, Yun Huang, and 4 more authors

   Journal of Asian Earth Sciences, May 2023

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   The Tanlu Fault is a significant fault in East China that has been associated with numerous destructive earth­ quakes in its central-south segment. However, the mechanisms behind these earthquakes remain unclear. This study aims to shed light on the seismic velocity structures of the crust and upper mantle under East China and their influence on the region’s seismotectonics. Our findings reveal that the upper mantle structures play a crucial role in regional seismotectonics. The 1668 Tancheng earthquake (M 8.5) is located above remarkable upper-mantle high-velocity bodies on both sides of the Tanlu Fault. Thus, it was likely produced by the inter­ action between the North China and Yangtze plates, with the lithospheric mantle significantly affecting the plate interaction. Another group of earthquakes of magnitude M 5–6 is located in the Subei–Yellow Sea Basin (SYSB). We have imaged a low-velocity body in the upper mantle, which is believed to represent hot and buoyant materials under the SYSB. This anonymous body may reduce the vertical stress in the crust and provide fluids to fault planes, thereby facilitating moderate-to-large earthquakes in the crust. These new findings provide valuable insight into the seismotectonics of East China, particularly the role of the upper mantle structures in shaping the region’s seismic activity.

4. Lithospheric deformation in Mongolia revealed by anisotropic Rayleigh wave tomography: Implications for the mechanism of intracontinental orogeny

   Xinglu Wang, Cong Ji, and Zhouchuan Huang

   Journal of Asian Earth Sciences, May 2023

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   The Mongolian Plateau is situated in the eastern part of the Central Asian Orogenic Belt that was formed during the Paleozoic era. In the Cenozoic era, the plateau has been reactivated, leading to significant topographic uplift, volcanism, and seismic activity. Several destructive earthquakes, ranging from magnitudes 6 to 8, have occurred in the 20th century. But the mechanism of these neotectonics remains unclear. To better understand these processes, we determined S wave velocity and azimuthal anisotropy in the crust and upper mantle under Mongolia using Rayleigh wave dispersion curves. Our findings indicate that the lithosphere is dominated by NWSE fast velocity directions (FVDs). However, we observed different patterns in two specific regions. The litho­ spheric anisotropy under the Hangay Dome is weak, suggesting that it is accompanied by significant mantle upwelling under the dome. On the other hand, the FVDs in the Gobi Desert exhibit a circular pattern that wraps around the Ordos Block, which may have been caused by past and present deformation imposed on the stable block. These results offer new insights into the lithospheric deformation and dynamics of the Mongolian Plateau.

5. Reproducing complex anisotropy patterns at subduction zones from splitting intensity analysis and anisotropy tomography

   Judith M Confal, Paola Baccheschi, Silvia Pondrelli, and 4 more authors

   Geophysical Journal International, Jul 2023

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   SUMMARY Measurements of seismic anisotropy provide a lot of information on the deformation and structure as well as flows of the Earth’s interior, in particular of the upper mantle. Even though the strong and heterogeneous seismic anisotropic nature of the upper mantle has been demonstrated by a wealth of theoretical and observational approaches , most of standard teleseismic body-wave tomography studies overlook P- and S-wave anisotropy, thus producing artefacts in tomographic models in terms of amplitude and localization of heterogeneities. Conventional methods of seismic anisotropy measurement have their limitations regarding lateral and mainly depth resolution. To overcome this problem much effort has been done to develop tomographic methods to invert shear wave splitting data for anisotropic structures, based on finite-frequency sensitivity kernels that relate model perturbations to splitting observations. A promising approach to image the upper mantle anisotropy is the inversion of splitting intensity (SI). This seismic observable is a measure of the amount of energy on the transverse component waveform and, to a first order, it is linearly related to the elastic perturbations of the medium through the 3-D sensitivity kernels, that can be therefore inverted, allowing a high-resolution image of the upper mantle anisotropy. Here we present an application of the SI tomography to a synthetic subduction setting. Starting from synthetic SKS waveforms, we first derived high-quality SKS SI measurements; then we used the SI data as input into tomographic inversion. This approach enables high-resolution tomographic images of upper-mantle anisotropy through recovering vertical and lateral changes in anisotropy and represents a propaedeutic step to the real cases of subduction settings. Additionally this study was able to detect regions of strong dipping anisotropy by allowing a 360° periodic dependence of the splitting vector.

2022

1. D″ anisotropy inverted from shear wave splitting intensity

   Chao Zhang, and Zhouchuan Huang

   Earthquake Science, Apr 2022

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2. Rayleigh wave tomography of central and southern Mongolia

   Xinglu Wang,  Hanting Wu,  Haibo Wang, and 2 more authors

   Tectonophysics, Aug 2022

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   The Mongolian Plateau located between the Siberian Craton and the North China Craton developed after mul­ tiple tectonic evolutions. It is proposed to be related to the far-field effect of the Indo-Asian collision in the Cenozoic. In this study, we inverted for high-resolution S wave velocity structures of Mongolia using Rayleigh wave tomography to constrain the plateau evolution. In particular, we obtained crustal and upper mantle seismic structures under Gobi Desert by combining Mongolian and Chinese datasets. The study reveals strong lowvelocity anomalies in the lower crust immediately beneath the Hangay Dome, while the low-velocity zones are imaged beneath the dome margins in the upper mantle. The results imply that the Hangay Dome was formed by mantle upwelling into the crust from major faults following lithospheric delamination. Under the South Gobi Desert, we imaged several inclined high-velocity patches in the upper mantle, indicating the subducted slabs formed in the Paleozoic. The ancient structures in the upper mantle led the Indo-Asian collision to propagate further to southern Mongolia.

3. Upper mantle anisotropy and deformation beneath the western Mongolian Plateau revealed by SKS splitting

   Hanting Wu, and Zhouchuan Huang

   Tectonophysics, Jul 2022

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   The Mongolian Plateau, as an important geological unit of the Central Asian Orogenic Belt, has experienced extensive deformations in multiple periods since the Proterozoic. In this study, we measured SKS splitting from 114 portable stations to reveal the complicated deformation of the upper mantle under western Mongolia. The predominant NW-SE-oriented fast polarization directions (FPDs) are consistent with lithospheric deformation and asthenospheric flow to the first order. However, the FPDs of the stations close to the Siberian Craton are more parallel to the cratonic margin than those departing from the craton. It indicates that the shape of the rigid Siberian Craton may determine the extent of the present lithospheric deformation and cause the deflection of the asthenospheric flow. Large SKS splitting delay times are distributed in the Hovsgol rift and Gobi-Altai range, implying superimposed past and present lithospheric anisotropy, and the asthenospheric anisotropy as well under the Hovsgol rift. Small delay times in the Hangai Dome indicate the asthenospheric upwelling which causes the uplift of the dome.

4. GRL

   Seismotectonics of Mongolia and Baikal Rift Zone Controlled by Lithospheric Structures

   Zhouchuan Huang, and Dapeng Zhao

   Geophysical Research Letters, Aug 2022

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   Active tectonics are developing in Mongolia and the Baikal rift zone, where large crustal earthquakes (Mw ≥ 6.0) occur frequently. To clarify the mechanism of these earthquakes, we determine a high-resolution 3-D P-wave velocity model of the crust and upper mantle beneath Mongolia and the Baikal rift zone. We find an annular high-velocity zone in the lithosphere; whereas low-velocity anomalies exist both inside and around the high-velocity ring as well as beneath the rift zone. Strong interactions between the high-velocity ring and the surrounding terranes may have induced many moderate-to-large earthquakes (Mw 5–7). By contrast, mega-earthquakes (Mw ≥ 8.0) occurred right above the high-velocity ring. We propose that the high-velocity ring is strong as a whole; it sustains the stress arising from the India-Asia collision and causes the mega-earthquakes. Meanwhile, the ring could protect the Hangay Dome from the regional compression, leading to weak seismicity under the dome.

5. Structural Heterogeneity of the Alaska‐Aleutian Forearc: Implications for Interplate Coupling and Seismogenic Behaviors

   Tao Gou, Shaohong Xia, Zhouchuan Huang, and 1 more author

   Journal of Geophysical Research: Solid Earth, Nov 2022

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   We determine high-resolution 3-D seismic images (Vp, Vs, and Vp/Vs) of the Alaska-Aleutian forearc region, which are used to further estimate the serpentinization volume fraction of the subducting Pacific slab. Our results show that the hydration degree of the lower plate is high in the Shumagin Gap but relatively low in the Semidi and Kodiak segments, which roughly shows a trend of eastward decrease that is correlated with an increase of the interseismic slip deficit rate. The variation of slab serpentinization degree derived from our Vp model shows an uneven decreasing trend, well consistent with the along-strike segmentation of interplate coupling and coseismic slip distributions of the 2020 Mw 7.8 Simeonof and 2021 Mw 8.2 Chignik megathrust earthquakes. The 2020 Mw 7.6 Sand Point earthquake took place within the strongly hydrated slab, whose occurrence was probably related to the variation of slip deficit rate that is probably affected by the changes in plate hydration. In addition, slow earthquakes occurred between the hydrated slab with pre-subduction structures (e.g., bending faults, seamounts, and fracture zones) and the fluid-saturated overriding crust and mantle wedge, where the intraslab seismicity and dehydration are intensive. These features suggest that lower-plate hydration and dehydration may affect the interplate coupling and seismogenic behaviors in subduction zones.

6. Stepwise Lithospheric Delamination Leads to Pulsed Cenozoic Uplifts of Central Tien Shan

   Haixiang Zhao, Zhouchuan Huang, and Xiaohui Yuan

   Lithosphere, Dec 2022

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   Abstract The Tien Shan provides an ideal site to study mechanism of intracontinental orogeny due to distant effect of Indo-Asian collision. We investigate lithospheric structures, in particular the lithosphere-asthenosphere boundary (LAB), of Central Tien Shan (CTS) using S wave receiver functions. The results show distinct structures across the orogen. Under the southern CTS, the LAB is shallower than that of the Tarim Basin; a 50 km vertical offset implies that part of the lithosphere has been delaminated. Under the middle CTS, two phases of negative velocity gradient are obtained, which may indicate a new LAB and an ongoing delamination underneath. Under the northern CTS and Kazakh Shield northward, the lithosphere is stable although the LAB inclines southward slightly. The two periods of lithospheric delamination under the southern and middle CTS account well for pulsed uplifts of the Tien Shan at ~11-8 Ma and ~5-0 Ma, respectively.

7. A relic thickened crustal root beneath the Cenozoic rift zone of the NW Ordos margin, North China, revealed by receiver functions

   Xuzhi Hu, Mijian Xu, Mingjie Xu, and 2 more authors

   Physics of the Earth and Planetary Interiors, Dec 2022

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   We investigate the crustal structure and Moho topography beneath the northwest Ordos rift zone by employing receiver functions analysis at dense broadband seismic stations. The results delineate a depressed Moho zone (by ~5 km) beneath the Cenozoic rifts, which is unconventional for classical continental rift zones. We interpret this depressed Moho zone as a relict of the thickened crustal root formed during the intracontinental orogeny in late Mesozoic. The Cenozoic rift has not yet reequilibrated the crustal-mantle boundary possibly due to the lack of decompressional melting during the lithospheric extension.

8. EPSL

   Restricted lithospheric extrusion in the SE Tibetan Plateau: Evidence from anisotropic Rayleigh-wave tomography

   Cunrui Han, Zhouchuan Huang, Shijie Hao, and 3 more authors

   Earth and Planetary Science Letters, Nov 2022

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9. Crustal and Uppermost Mantle Heterogeneities Across the Ailaoshan Red River Shear Zone, SE Tibet: Implications for Cenozoic Magmatic Activity

   Mijian Xu, Dayong Yu, Zhouchuan Huang, and 4 more authors

   Journal of Geophysical Research: Solid Earth, Jun 2022

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   The Ailaoshan Red River shear zone (ARSZ) was formed in the Mesozoic as a suture zone between the Indochina block and the Yangtze craton. Since the Cenozoic, block extrusion due to the Indo-Asian collision has reactivated the fault zone and caused large-scale shearing. Affected by the Cenozoic orogeny, a large volume of magmatic and metamorphic rocks developed in the ARSZ, forming many orogenic gold deposits. However, the source and the geodynamic process of these magmatic activities are still unclear. To gain a basic understanding of the subsurface magmatic activity, we deployed a dense array of 24 broadband seismic stations across the Daping and Chang’an gold deposits at the southern end of the ARSZ. Receiver function analysis, common conversion point stacking, and a joint inversion of receiver functions and surface wave dispersions are performed to image the detailed structure of the crust and uppermost mantle. Low-velocity zones in the mid-lower crust and thinned lithosphere (∼70 km) are imaged under the ARSZ. The observed subsurface structures are verified by 3D numerical modeling with the SEM-FK method. We speculate that the mantle upwelling caused by lithospheric delamination has provided the main source of the mantle component in the magmatic rocks since ∼35 Ma; afterward, high temperatures produced partial melting in the lower crust, which was emplaced along active shear zones.

10. 地震体波速度与各向异性层析成像研究进展

    黄周传

    地球与行星物理论评, Jun 2022

2021

1. Mantle Convection in Subduction Zones: Insights from Seismic Anisotropy Tomography

   Zhouchuan Huang, and Dapeng Zhao

   In Geophysical Monograph Series, Jul 2021

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   Lithospheric plates descend into the mantle and drive mantle upwelling in subduction zones, causing large earthquakes and vigorous magmatism along island arcs and continental margins. These processes induce different stress and strain regimes at different depths and generate varying seismic anisotropies. Hence, measurements of seismic anisotropy provide straightforward constraints on the subduction processes, in particular, mantle convection in subduction zones. High-resolution images of seismic anisotropy tomography obtained in the past decade have provided essential and direct information on the anisotropy in subduction zones. These new findings well constrain deformations in the overriding plates, subducting slabs, and mantle flows adjacent to the slabs. The anisotropy in the slabs, either trench-normal or trench-parallel, changes at different depths, reflecting either frozen-in fossil anisotropy or current slab deformations accompanying subduction. In the mantle wedge, dominant trench-normal anisotropy arises from extensive corner flow caused by the subduction, with notable 3D flow and trench-parallel anisotropy due to along-arc variations. In the subduction channel, trench-parallel and subduction-parallel anisotropies are revealed in strong and weak coupling areas, respectively. In the sub-slab mantle, there is still debate on entrained flow caused by subduction (inducing trench-normal anisotropy) and 3D flow caused by trench retreat (inducing trench-parallel anisotropy).

2. Mantle dynamics in the SE Tibetan Plateau revealed by teleseismic shear-wave splitting analysis

   Zhouchuan Huang, and Sébastien Chevrot

   Physics of the Earth and Planetary Interiors, Apr 2021

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   The tectonic evolution of the southeastern Tibetan Plateau is key to understanding the mechanism of growth of the whole Tibetan Plateau. Its imprint on lithospheric and asthenospheric mantle rock fabrics is expected to have a strong signature on seismic anisotropy. In this study, we measure the splitting delays and fast polarization directions (FPD) with the minimum-transverse-energy and the splitting intensity methods using core-refracted phases (e.g., SKS, SKKS, PKS) recorded by the ChinArray experiment. The potential complex anisotropic struc­ tures, i.e., the frequency-dependent splitting and two-layer anisotropy, are investigated in particular. The FPDs are consistent in different frequency bands, but the delay times measured at low frequency (8–20 s) are often larger than those measured at high frequency (2–8 s). The measurements can be better explained by a two-layer anisotropy model at many stations. Splitting intensities are also inverted to constrain the depth distribution of seismic anisotropy in the upper mantle. Combined with the two-layer anisotropy models, these results suggest different patterns of seismic anisotropy in the lithosphere and asthenosphere. In the lithosphere, anisotropy shows distinct patterns in the different tectonic blocks, while the FPDs are oriented along the major tectonic boundaries. In the asthenosphere, continuous NW-SE FPDs spread from the Tibetan plateau to the Youjiang Orogen along the southwestern margin of the Yangtze craton, implying asthenospheric extrusion from the high plateau. In the northern Indochina block, the dominant E-W FPDs may indicate asthenospheric flow driven by the eastern subduction and subsequent rollback of the Indian plate.

3. Seismic structure and subduction dynamics of the western Japan arc

   Dapeng Zhao, Jian Wang, Zhouchuan Huang, and 1 more author

   Tectonophysics, Mar 2021

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4. EPSL

   Layered crustal azimuthal anisotropy beneath the northeastern Tibetan Plateau revealed by Rayleigh-wave Eikonal tomography

   Shijie Hao, Zhouchuan Huang, Cunrui Han, and 4 more authors

   Earth and Planetary Science Letters, Jun 2021

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5. Deep structure beneath the southwestern flank of the Baikal rift zone and adjacent areas

   Hanting Wu, Zhouchuan Huang, and Dapeng Zhao

   Physics of the Earth and Planetary Interiors, Jan 2021

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   The origin of the Baikal rift zone is under debate between active and passive rifting hypotheses owning to the enigmatic deep structure beneath the region. Revealing the formation mechanism of the Baikal rift zone may help to elucidate the process of continental rifting. Applying P-wave teleseismic tomography to an improved data set, we discover low-velocity anomalies under the southwestern flank of the Baikal rift zone, which are inter­ preted as hot mantle upwellings from under the Siberian craton, indicating hot materials transferring from beneath the craton to beneath the rift. Our images also reveal low-velocity anomalies under the Hangai Dome, probably suggesting the process of delamination, another consequent effect connected to the Siberian upwellings. We propose that the mantle upwellings beneath the Baikal rift zone and surrounding areas play a vital role in the formation of deep structures and geological settings in this area.

6. Lithospheric structures beneath the western Mongolian Plateau: Insight from S wave receiver function

   Haixiang Zhao, Pan Wang, and Zhouchuan Huang

   Journal of Asian Earth Sciences, Jun 2021

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   The Mongolian Plateau is located in the western segment of the Central Asian Orogenic Belt. In the Cenozoic, the western plateau was affected by the India-Asian collision; the Hangay Dome of a low-relief plateau has been formed. However, the mechanism of the uplift of the plateau and particularly the Hangay Dome is debated. In this study, we image the lithosphere-asthenosphere boundary (LAB) with S wave receiver functions. The LAB is much shallower beneath the western Mongolian Plateau (~80–90 km) than beneath the North China Craton (~150 km) and Siberian Craton (~180 km). We also found another possible deep LAB at 200–250 km depths beneath the Hangay Dome, indicating a lithospheric delamination beneath western Mongolia. Thus we conclude that the consequential asthenospheric upwelling caused the tectonic uplift of the Hangay Dome.

7. P and S wave tomography of east-central China: insight into past and present mantle dynamics

   Zhouchuan Huang, Tao Gou, and Liangshu Wang

   Tectonophysics, Jun 2021

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   East-central China has experienced multi-stage evolution among different tectonic units; thus the present geological structures are superimposed in a long history. But it is still unclear how different tectonic processes interact with each other, especially how the subsequent activity affects the previous structures. In this study, we determined new high-resolution P and S wave tomography of the upper mantle beneath the east-central China. We imaged the stagnant Pacific slab in the mantle transition zone and the hot low-velocity upper mantle in eastern China while cold high-velocity bodies beneath the Archean cratons in central China. More importantly, we newly revealed two important features. Firstly, a high-velocity zone is found in the uppermost mantle (50–150 km) beneath the Southeast China; its location is comparable to the distribution of the Cretaceous igneous rocks. Thus, we propose that the high-velocity anomalies reflect the remnant mafic rocks in the upper mantle after the volcanic eruption. Secondly, a high-velocity body is revealed in the deep upper mantle (300–500 km) beneath the southwestern Yangtze craton, possibly implying the delaminated cratonic lithosphere in the Early Mesozoic.

8. 青藏高原东南缘地壳结构与变形机制研究进展

   黄周传,  吉聪,  吴寒婷, and 6 more authors

   地球与行星物理论评, Jun 2021

2020

1. Lateral variation of the mantle transition zone beneath the Tibetan Plateau: Insight into thermal processes during Indian–Asian collision

   Mijian Xu, Zhouchuan Huang, Liangshu Wang, and 3 more authors

   Physics of the Earth and Planetary Interiors, Apr 2020

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   The Indian plate began to subduct under the Eurasian plate in the late Mesozoic. Since the Eocene, continuous continental collision has resulted in the uplift of the Tibetan Plateau with extensive volcanic activities. Geophysical and geochemical studies have suggested that the Indian plate subducted and that volcanism originated in the deep upper mantle. However, the depth range of the subduction and volcanism and the relationship between them are still unclear. Here, to image the mantle transition zone (MTZ) structures, we deployed new seismic stations and collected as much seismic data as possible from the Tibetan Plateau. We then calculated the receiver functions and analyzed them using the common conversion point stacking method. We found that the MTZ is thickened by ~20 km under the Lhasa block, where high-velocity anomalies are obvious in the MTZ. Apparent thinning of the MTZ by ~20 km was revealed under the Qiangtang and Songpan-Ganze blocks, confirming a component of depleted mid-oceanic ridge basalt in the magmatic rocks. Our results suggest that the Indian Plate has at least subducted to the MTZ, which has further induced mantle upwelling and volcanism in the Tibetan Plateau.

2. Seismic tomography in the southern margin of the Sichuan Basin: Insight into the plateau-craton interaction and seismotectonics in the SE Tibetan Plateau

   Haibo Wang, and Zhouchuan Huang

   Journal of Asian Earth Sciences, Sep 2020

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   The expansion of the Tibetan Plateau in its southeastern margin causes high seismic hazards in southwest China, even if some earthquakes are located far away from the expansion frontier in the southern Sichuan Basin. In this study, we determined the high-resolution P-wave velocity structure of the crust beneath the southern margin of the Sichuan Basin with an updated data set. We find low-velocity anomalies in the upper and lower crust whereas high-velocity anomalies between them; large earthquakes are spatially related to the low-velocity anomalies in the lower crust. The results indicate that the southern margin of the Sichuan Basin has been weakened laterally by the deep crustal extrusion related to the expansion of the SE Tibetan Plateau. We infer that the shallow crust might have been broken in association with the strike-slip faults during the plateau expansion, leading to large earthquakes.

3. Tectonic evolution of the eastern margin of the Tibetan plateau: Insight from crustal structures using P wave receiver functions

   Muyu Tian, Zhouchuan Huang, Liangshu Wang, and 9 more authors

   Journal of Asian Earth Sciences, Apr 2020

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   The eastern margin of the Tibetan plateau is under ongoing expansion. Rise and growth of the Longmenshan are results of the interaction between the Songpan-Ganzi Terrane and the Sichuan Basin. In order to understand the block interactions in the eastern plateau margin, we studied the crustal structures using P wave receiver functions (including H-k staking, CCP stacking, and velocity inversion) with the waveforms recorded by 115 portable stations. The Moho, indicated by clear Ps phases, is generally deeper in the Songpan-Ganzi Terrane than in the Sichuan Basin, while a step is notable under the Longmenshan fault zone. We found a low velocity anomaly in the mid-lower crust below the Songpan-Ganzi Terrane and Longmenshan fault zone, which may imply the accumulated partial melting materials in the deep crust under the eastern plateau margin. Clear P-to-s converted phases are found within the crust of the Sichuan Basin. They look as apparent huge anticline structures, which may be caused by ancient crustal deformation under the stable craton.

4. Layered crustal anisotropy and deformation in the SE Tibetan plateau revealed by Markov-Chain-Monte-Carlo inversion of receiver functions

   Cunrui Han, Mijian Xu, Zhouchuan Huang, and 9 more authors

   Physics of the Earth and Planetary Interiors, Sep 2020

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   The southeastern (SE) Tibetan plateau is uplifting accompanying strong seismicity, but the relationship between the crustal structure and tectonic process in this region is still unclear. Seismic anisotropy provides important clues for the deformation mechanism. Here we applied the harmonic decomposition approach and further conducted a Markov-Chain-Monte-Carlo (MCMC) inversion to analyze the crustal anisotropy from receiver functions using waveforms recorded by dense stations in the SE Tibetan plateau. More spatial details on the crustal anisotropy and interface are determined consequently. While the anisotropies in the upper crust are relatively weak (~2%), the anisotropies in the mid-lower crust are mostly stronger than 4%. The fast polarization directions (FPDs) in the mid-lower crust show a dominant circular pattern, in good coherence with the topographic contours, indicating that the crustal deformations in the SE Tibetan plateau may be mainly controlled by the gravity potential. Because of the significant Moho steps along the plateau margin, the extruded deep crustal materials are blocked by the strong crust around so that the minerals are aligned to be sub-parallel to the plateau margins.

5. A Method for Estimating the Crustal Azimuthal Anisotropy and Moho Orientation Simultaneously Using Receiver Functions

   Pan Wang, Zhouchuan Huang, and Xingchen Wang

   Journal of Geophysical Research: Solid Earth, Feb 2020

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   The P‐to‐S converted phase at the Moho (the Pms phase) contains important information regarding the crustal structure. Here, we employ a grid search approach to simultaneously extract the bulk crustal azimuthal anisotropy and Moho orientation using receiver functions. The solution of this approach is the weighted average of two individual subfunctions that separately analyze the birefringence and arrival time of the Pms phase. Since a tilted Moho deflects the polarized components of the Pms phase, the Pms birefringence subfunction minimizes the energy on all the transverse polarization components (i.e., the transverse polarization direction before Pms splitting). The implementation of this subfunction is similar to that of the transverse component minimization method, but the Moho orientation is considered. The Pms arrival time subfunction takes into account both the crustal anisotropy and the Moho orientation to predict and fit Pms arrivals. According to extensive synthetic experiments, this approach is remarkably robust to the presence of strong anisotropy, a steep Moho, and slightly tilted fast axes (less than 30°). This approach is also highly tolerant of random noise and data with uneven azimuthal coverage. We apply this approach to three permanent stations on the Tibetan Plateau. The resulting measurements boast a high quality and are consistent with the crustal anisotropy and Moho orientation revealed in previous studies.

6. JGR

   Sharp Lateral Moho Variations Across the SE Tibetan Margin and Their Implications for Plateau Growth

   Mijian Xu, Zhouchuan Huang, Liangshu Wang, and 5 more authors

   Journal of Geophysical Research: Solid Earth, May 2020

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   The tectonic uplift of the Tibetan Plateau is a focus in the geosciences. Middle‐lower crustal flow is a popular model to interpret the geodynamic mechanism on the margin of the Tibetan Plateau. The model predicts different surface and Moho topographies across the plateau boundary due to the different strengths of the surrounding blocks, that is, sharp boundaries on the eastern plateau boundary and gentle variations in the southeastern plateau boundary. Here, we employ receiver function and common conversion point stacking analysis with the seismic waveforms recorded by the dense ChinArray and other local seismic stations to accurately define the Moho topography in southeastern (SE) Tibet. We find that the Moho under the Tibetan Plateau is much deeper than that under the surrounding Yangtze Craton and Indochina block; abrupt Moho changes are found across the southeastern plateau margin, similar to that under the eastern plateau margin. We interpret these sharp Moho variations across the plateau margin to have developed when the Tibetan Plateau was extruded southeastward in the late Miocene. Subsequent gravity collapse resulted in crustal extension and gentle topographic variation, while the sharp Moho slope was preserved.

7. Isotropic and Anisotropic \textitP Wave Velocity Structures of the Crust and Uppermost Mantle Beneath Turkey

   Haibo Wang, Zhouchuan Huang, Tuna Eken, and 7 more authors

   Journal of Geophysical Research: Solid Earth, Dec 2020

   Abs URL

   Compressional and extensional tectonics following northward plate convergences since the Miocene have formed the major surface features in Turkey, such as faulting and orogeny. Despite increasing efforts in last few decades aiming to elucidate the current architecture of the crust and mantle beneath Turkey, several issues regarding the depth extent of the deformation zones, crust‐mantle interaction (e.g., coupling and decoupling) in relation to the deformation, and stress transmission in the lithosphere remain elusive. Here we present high‐resolution 3‐D P wave isotropic and azimuthal anisotropic velocity models of the crust and uppermost mantle beneath Turkey by inverting 204,531 P wave arrival times of 8,103 local crustal earthquakes. Our results reveal low‐velocity anomalies or velocity contrasts down to the uppermost mantle along the North and East Anatolian Fault Zones. The fast velocity directions (FVDs) of azimuthal anisotropy in the lower crust and uppermost mantle are parallel to the regional maximum extensional directions in western Turkey, and the FVDs in the crust and uppermost mantle are parallel to the surface structures in southeastern Turkey. These results indicate that vertically coherent deformation between the crust and uppermost mantle occurs in western and southeastern Turkey. However, in central northern Turkey, the FVDs in the uppermost mantle are oblique to both the FVDs in the lower crust and the maximum shear directions derived from GPS measurements, suggesting that the crust and lithospheric mantle are decoupled there.

8. Structural Heterogeneity in Source Zones of the 2018 Anchorage Intraslab Earthquake and the 1964 Alaska Megathrust Earthquake

   Tao Gou, Dapeng Zhao, Zhouchuan Huang, and 1 more author

   Geochemistry, Geophysics, Geosystems, Mar 2020

   Abs URL

   Structural heterogeneities in subduction zones can affect slip behaviors of the megathrust faults and the generation of intraslab earthquakes. In this work we study the 3‐D seismic structures (Vp, Vs, and Poisson’s ratio) in and around the source zones of the 2018 Anchorage intraslab earthquake (Mw 7.1) and the 1964 Alaska megathrust earthquake (Mw 9.2). The Anchorage earthquake occurred in an anomalous zone within the subducting Yakutat/Pacific plate with a higher Poisson’s ratio than the normal slab. Above the source zone, the overriding North American plate shows a low Vs and a high Poisson’s ratio. These features indicate that strong dehydration occurs in the source zone and released fluids ascend into the overlying crust. Two areas with long‐term slow slip events in the Upper and Lower Cook Inlet predominantly exhibit a high Poisson’s ratio in the lowermost portion of the crust and the cold nose of the mantle wedge, whereas a low Poisson’s ratio zone is revealed between them, suggesting that their segmentation is possibly related to localized slab‐releasing fluids. In the Prince William Sound, the rupture of the 1964 Great Alaska earthquake initiated beneath a high‐V and high Poisson’s ratio zone of the overlying crust and the large slips occurred beneath a low‐Vs and high Poisson’s ratio zone, suggesting that lateral heterogeneities of the overriding plate may have played an important role in the nucleation and rupture processes of the Great Alaska earthquake.

9. Upper‐Mantle Anisotropy and Dynamics Beneath Northeast Asia: Insight From SKS and Local \textitS Splitting Analysis

   Yajing Bi, Zhouchuan Huang, Haibo Wang, and 1 more author

   Geochemistry, Geophysics, Geosystems, Aug 2020

   Abs URL

   Tectonics in Northeast Asia are characterized as the deep subduction of the Pacific Plate and the induced volcanism in Northeast China. Seismic anisotropy due to deformations is essential for understanding the mantle dynamics. However, the routine SKS splitting captures the accumulated seismic anisotropy from core‐mantle boundary to the surface, so the interpretation of the SKS splitting measurements is nonunique. Here, benefiting from abundant deep‐focus earthquakes in the subducting Pacific Plate, we measured shear wave splitting using both the SKS and local S waves recorded at Station MDJ to discriminate the anisotropy at different depths under Northeast China. We obtained 61 SKS and 22 local S wave splitting parameters. The SKS splitting measurements show apparent azimuthal variations that can be modeled by two‐layer anisotropy. The fast polarization directions (FPDs) of anisotropy in the upper and lower layers are NE‐SW and NW‐SE, which may be explained by the lithospheric deformation accompanying the Mesozoic fault activity and the asthenospheric deformation due to motion of the Eurasian Plate, respectively. The FPDs of the local S wave splitting measurements are parallel to the direction of the Pacific Plate subduction; the variation of the delay times is related to the take‐off angles. The observations can be explained by the inclined symmetry axis of the aligned metastable olivine in the subducting Pacific Plate.

10. 青藏高原东北缘瑞利面波成像:射线理论与程函方程结果的比较

    郝识杰,  黄周传,  王良书, and 3 more authors

    高校地质学报, Aug 2020

2019

1. Stress Field in the 2016 Kumamoto Earthquake ( \textitM 7.3) Area

   Zhiteng Yu, Dapeng Zhao, Jiabiao Li, and 3 more authors

   Journal of Geophysical Research: Solid Earth, Mar 2019

   Abs URL

   We used 1‐D and 3‐D velocity models to determine focal mechanism solutions (FMSs) of 349 crustal earthquakes (M 2.7–7.3) and stress tensors in the source area of the 2016 Kumamoto earthquake (M 7.3) that occurred on the Futagawa‐Hinagu fault zone in Kyushu, Southwest Japan. There are some differences in the FMSs determined with the 1‐D and 3‐D velocity models. The use of the 3‐D velocity model leads to better results of stress tensors, which are determined by inverting the FMSs. The orientation of the minimum stress (σ3) axis is more accurately determined, which trends NNW‐SSE to N‐S nearly horizontally. In contrast, the axes of the maximum and intermediate stresses (σ1 and σ2) trend WSW‐ENE to E‐W with wide ranges. Significant spatiotemporal variations of the stress field are revealed in the Kumamoto source zone, indicating a small magnitude of deviatoric stress. The friction coefficient of the faults is estimated to be relatively small (~0.4), indicating that the seismogenic faults in central Kyushu are weak. The fault weakening may be caused by fluids beneath the source area and arc magma under the nearby Aso active volcano.

2. Tomography, Seismotectonics, and Mantle Dynamics of Central and Eastern United States

   Haibo Wang, Dapeng Zhao, Zhouchuan Huang, and 1 more author

   Journal of Geophysical Research: Solid Earth, Aug 2019

   Abs URL

   We study the 3‐D P wave velocity structure of the crust and mantle down to 1,000‐km depth beneath the central and eastern United States. A 3‐D velocity model is obtained by conducting a joint inversion of 236,670 arrival times of local earthquakes and 870,455 relative traveltime residuals of teleseismic events recorded by the EarthScope/USArray Transportable Array. Significant low‐velocity (low‐V) anomalies are revealed in the crust beneath the eastern arm of the Midcontinent Rift and the Triassic Basins along the East Coast, whereas a prominent high‐velocity (high‐V) anomaly is visible beneath the Llano Uplift in central Texas. The stable North American Craton exhibits high‐V anomalies at depths of 65–250 km. Low‐V anomalies exist along the eastern and southern margins of the craton, which may reflect relatively thin lithosphere there. A prominent low‐V anomaly is revealed at depths of 50–200 km beneath the New Madrid Seismic Zone, which is bounded by high‐V anomalies to its southeast and northwest. This feature reflects a weak lithosphere surrounded by relatively strong cratonic regions and stress concentration caused intraplate seismicity in the New Madrid region. Two high‐V bodies appear in the mantle transition zone (410‐ to 660‐km depths) beneath the Interior Low Plateaus, the central Great Plains, and the Central Lowland, which may reflect the subducted Farallon plate or delaminated lithosphere. At depths of 800–1,000 km, a high‐V anomaly is visible beneath the southeast United States, which may be the subducted Hess Rise conjugate.

3. Imaging the Mantle Lithosphere below the China cratons using S-to-p converted waves

   Xuzhang Shen, Rainer Kind, Zhouchuan Huang, and 2 more authors

   Tectonophysics, Mar 2019

   Abs URL

   We used S-to-p converted waves from over a thousand seismic stations of the permanent Chinese National Seismic Network to study the large scale structure of the mantle lithosphere beneath the cratons in China. To avoid possible sidelobes of the Moho caused by the deconvolution in the S-receiver function method, we skipped the deconvolution and used the SV onset time as reference time instead of the time of the deconvolution spike. With this new method the lithosphere-asthenosphere boundary (LAB) is observed near 80 km depth below both the North and the South China cratons. However, at the north-eastern margin of the Tibetan Plateau the LAB is observed at about 160 km depth, smoothly shallowing towards the west and abruptly ending at the western end of the North China Craton. This structure is not visible in traditional S-receiver function data because it is overwhelmed by Moho sidelobes. There is no indication of a deeper (near 200 km) cratonic lithosphere-asthenosphere boundary in the other parts of the China cratons as it is observed in other cratons. We hypothesise that at the north-eastern margin of the Tibetan Plateau the original thickening of the lithosphere towards the craton is preserved whereas in most parts of the North and South China Cratons the lower part of the lithosphere is removed by some mechanism. The Moho is well observed. It deepens from 30 to 40 km at the sea shores in the east to 60–70 km below eastern Tibetan Plateau.

4. Focal mechanism and stress field in the northeastern Tibetan Plateau: insight into layered crustal deformations

   Cunrui Han, Zhouchuan Huang, Mingjie Xu, and 4 more authors

   Geophysical Journal International, Sep 2019

   Abs URL

   Focal mechanism solutions (FMSs) reflect the stress field underground directly. They provide essential clue for crustal deformations and therefore improve our understanding of tectonic uplift and expansion of the Tibetan Plateau. In this study, we applied generalized Cut and Paste and P-wave first-motion methods to determine 334 FMSs (2.0 ≤ Mw ≤ 6.4) with the data recorded by a new temporary network deployed in the NE Tibetan Plateau by ChinArray project. We then used 1015 FMSs (including 681 published FMSs) to calculate the regional stress field with a damped linear inversion. The results suggest dominant thrust and strike-slip faulting environments in the NE Tibetan Plateau. From the Qilian thrust belt to the Qinling orogen, the maximum horizontal stress orientations (SH ) rotate clockwise from NNE to NE, and further to EW, showing a fan-shaped pattern. The derived minimum horizontal stress orientations (Sh) are parallel to the aligned fabrics in the mantle lithosphere indicated by shear wave splitting measurements, suggesting vertically coherent deformation in the NE Tibetan Plateau. Beneath the SW Qinling adjacent to the plateau, however, the stress orientations in the shallow and deep crust are different, whereas the deep crustal stress field indicates possible ductile crustal flow or shear.

5. Structural Heterogeneity and Anisotropy in the Source Zone of the 2018 Eastern Iburi Earthquake in Hokkaido, Japan

   Tao Gou, Zhouchuan Huang, Dapeng Zhao, and 1 more author

   Journal of Geophysical Research: Solid Earth, Jul 2019

   Abs URL

   We investigate 3‐D seismic structures (Vp, Vs, and Poisson’s ratio) and Vp azimuthal anisotropy in the source area of the 2018 Eastern Iburi earthquake (M 6.7) in Hokkaido, Japan. Its mainshock occurred at the edge of a high‐Vp (2–4%) seismogenic zone. Significant low‐Vs (−1% to −3%) and high Poisson’s ratio (2–7%) anomalies are imaged in and below the source zone and extend to the upper surface of the subducting Pacific slab, most likely reflecting ascending fluids released by the slab dehydration. A high consistency between the fault plane and the low‐Vs and high Poisson’s ratio anomalies indicates that the fluids may have entered the fault and affected the rupture nucleation. A high‐V (1–3%) anomaly is revealed in the fore‐arc mantle wedge and connects with the high‐V seismogenic zone, probably reflecting a lithospheric fragment and contributing to cool down the mantle wedge. Complex seismic anisotropy is revealed in the crust in and around the source area, which may reflect complicated stress regime and strong structural heterogeneities there.

6. Aseismic Deep Slab and Mantle Flow Beneath Alaska: Insight From Anisotropic Tomography

   Tao Gou, Dapeng Zhao, Zhouchuan Huang, and 1 more author

   Journal of Geophysical Research: Solid Earth, Feb 2019

   Abs URL

   We present high‐resolution 3‐D images of P wave velocity (Vp), azimuthal anisotropy (AAN), and radial anisotropy (RAN) down to 900‐km depth beneath Alaska obtained by inverting a large number of high‐quality arrival time data from local earthquakes and teleseismic events simultaneously. Our results show that the high‐Vp Pacific slab has subducted down to 450‐ to 500‐km depths. A prominent slab gap is revealed at depths of 65–120 km near the Wrangell volcanic field, which is likely a slab tear acting as a channel that provides ascending mantle materials to generate magmas feeding the surface volcanoes. In the back‐arc mantle wedge near the eastern slab edge, the AAN exhibits trench‐parallel fast‐velocity directions (FVDs), which may reflect along‐strike mantle flow. The FVDs in the subducting Pacific slab are nearly east‐west, which may indicate fossil anisotropy formed at the mid‐ocean ridge. A negative RAN is revealed within the subducting slab, which may be caused by the fast plate subduction with a steep dip angle. Trench‐normal FVDs of the AAN are revealed in the mantle below the Pacific slab, which may reflect mantle flow entrained by the subducting slab. A positive RAN is revealed in the mantle beneath the Yakutat slab, indicating that its shallow subduction flattens the mantle flow below the slab to be subhorizontal. Along‐strike FVDs of the AAN around the eastern slab edge may indicate the edge‐induced toroidal mantle flow.

7. Geochemical analysis of Lake Baikal sediments: review of the results of the Sino-Russian joint expedition at Lake Baikal as a scientific training project

   Zini Yan, Jinhui Li, Zihui He, and 4 more authors

   Earth sciences and subsoil use, Dec 2019

   Abs URL

   The article presents the materials that have been collected, processed and prepared for publication by the students participating in the international Sino-Russian scientific educational field expedition “Baikal as the world’s pearl, 2019” organized by Nanjing University and Irkutsk Research Technical University. For the purposes of the field studies, samples of the recent sediments of different genesis have been taken. The further office studies have been conducted using the laboratory equipment of the training research divisions of the School of Earth Sciences and Engineering, and the School of Environment, Nanjing University. As a result of the factual material processing, the comprehensiveness of the data has been evaluated, and the directions for further studies have been defined, which will allow to deepen and expand the scientific concepts of the history of the paleogeographic and climatic conditions of the West Transbaikalia sediments formation. The work has been conducted under the supervision of Professor R.M. Lobatskaya (Irkutsk National Research Technical University) on the Russian side, and Professors Wei Li and Zhouchuan Huang (Nanjing University) on the Chinese side.

8. \textitP Wave Azimuthal Anisotropic Tomography in Northern Chile: Insight Into Deformation in the Subduction Zone

   Zhouchuan Huang, Frederik Tilmann, Diana Comte, and 1 more author

   Journal of Geophysical Research: Solid Earth, Jan 2019

   Abs URL

   Based on a large data set of local body wave travel times, we determined the first 3‐D model of azimuthal P wave anisotropic tomography of northern Chile in order to study the deformation in the subduction zone. Our results indicate different deformation patterns in the overriding lithosphere, mantle wedge, and the subducting Nazca slab as well as significant along‐arc variations. Radiating fast velocity directions (FVDs) around the rupture zone of the 2014 Iquique earthquake (Mw 8.2) are notable in the crust, which may reflect the specific crustal extension induced by a point‐like stress source in the form of a fully locked asperity at the plate interface. In most of the study region, FVDs in the mantle wedge are trench normal, which we interpret to have resulted from mantle wedge flow driven by the oceanic plate subduction. However, trench‐parallel FVDs are found beneath the northern segment, which may imply the occurrence of B‐type olivine fabrics in the cold forearc mantle. Strong along‐arc variations are also observed in the subducting slab, which may reflect intraslab heterogeneity and change in the slab geometry. In the northern segment, slab bending induces generally trench‐normal extension and leads to trench‐normal FVDs in the upper part of the slab. In contrast, in the southern segment, flat slab subduction and thus slab unbending dominate, producing trench‐normal compression and trench‐parallel FVDs instead. Along the subducting slab interface, FVDs change from trench‐parallel to trench‐normal in the downdip direction, which may indicate the first‐order transition from compression in the locking area to dominant shear in the decoupling area along the slab interface.

9. JGR

   \textitP and \textitS Wave Tomography Beneath the SE Tibetan Plateau: Evidence for Lithospheric Delamination

   Zhouchuan Huang, Liangshu Wang, Mingjie Xu, and 3 more authors

   Journal of Geophysical Research: Solid Earth, Oct 2019

   Abs URL

   The SE Tibetan Plateau is located between the eastern Himalayan syntaxis and the stable Yangtze craton; its tectonic evolution is important for understanding the plateau expansion. However, interactions between the plateau and its adjacent subduction zone and craton are still unclear. In this study, we determine updated high‐resolution P and S wave tomographic models of the crust and upper mantle beneath the SE Tibetan Plateau. We confirmed the existence of a high‐velocity layer in the upper mantle down to 200‐km depth beneath the Sichuan basin, the core of the Yangtze craton, representing the stable cratonic root. Another high‐velocity body is located beneath Burma, reflecting the subducting Indian slab in the upper mantle and possibly the remnant Burman slab in the mantle transition zone. A strong low‐velocity column exists above the high‐velocity body in the transition zone and reaches the Moho under the Tengchong volcano. In addition, we find high‐velocity fragments in the upper mantle beneath the Yangtze craton and northern Indochina, which may reflect delaminated lithosphere beneath the SE Tibetan Plateau. The lithospheric delamination may be closely related to mantle flow extruded from the high plateau and possible thermal upwelling from the lower mantle. Our results provide new insight into the deep interactions between the Tibetan plateau and its surrounding blocks near the SE plateau margin.

2018

1. 

   Crustal tomography of the 2016 Kumamoto earthquake area in West Japan using P and PmP data

   Haibo Wang, Dapeng Zhao, Zhouchuan Huang, and 4 more authors

   Geophysical Journal International, Aug 2018

   Abs Bib URL

   A high-resolution model of 3-D P-wave velocity (Vp) tomography of the crust in the source area of the 2016 Kumamoto earthquake (M 7.3) in West Japan is determined using a large number of arrival times of first P waves and reflected P waves from the Moho discontinuity (PmP). The PmP data are collected from original seismograms of the Kumamoto aftershocks and other local crustal events in Kyushu. Detailed resolution tests show that the addition of the PmP data can significantly improve the resolution of the crustal tomography, especially that of the lower crust. Our results show that significant low-velocity (low-V) anomalies exist in the entire crust beneath the active volcanoes, which may reflect the pathway of arc magma. The 2016 Kumamoto earthquake occurred at the edge of a small low-V zone in the upper crust. A significant low-V anomaly is revealed in the lower crust beneath the source zone, which may reflect the arc magma and fluids ascending from the mantle wedge. These results suggest that the rupture nucleation of the 2016 Kumamoto earthquake was affected by fluids and arc magma.

   @article{wang_crustal_2018,
     title = {Crustal tomography of the 2016 {Kumamoto} earthquake area in {West} {Japan} using {P} and {PmP} data},
     volume = {214},
     issn = {0956-540X, 1365-246X},
     url = {https://academic.oup.com/gji/article/214/2/1151/4992741},
     doi = {10.1093/gji/ggy177},
     language = {en},
     number = {2},
     urldate = {2022-08-10},
     journal = {Geophysical Journal International},
     author = {Wang, Haibo and Zhao, Dapeng and Huang, Zhouchuan and Xu, Mingjie and Wang, Liangshu and Nishizono, Yukihisa and Inakura, Hirohito},
     month = aug,
     year = {2018},
     pages = {1151--1163},
   }

2. Insight into the subducted Indian slab and origin of the Tengchong volcano in SE Tibet from receiver function analysis

   Mijian Xu, Hui Huang, Zhouchuan Huang, and 7 more authors

   Earth and Planetary Science Letters, Jan 2018

   URL
3. Anisotropic 3‐D Ray Tracing and Its Application to Japan Subduction Zone

   Tao Gou, Dapeng Zhao, Zhouchuan Huang, and 1 more author

   Journal of Geophysical Research: Solid Earth, May 2018

   Abs URL

   A new 3-D ray tracing technique is developed to determine seismic raypaths and theoretical travel times in weak radial anisotropic media. Anisotropic schemes of the pseudo-bending technique and Snell’s law are derived and used iteratively to find the fastest ray trajectory. Many synthetic tests are performed to evaluate the accuracy of our algorithm and investigate the raypath differences between the 3-D isotropic and anisotropic rays. The test results show that the travel time and raypath differences are smaller than 0.1 s and 10 km, respectively. Applying our technique to a model of radial anisotropy tomography of the Japan subduction zone, we find visible travel time and raypath differences due to variations of the 3-D isotropic velocity and radial anisotropy, but the travel time difference caused by the radial anisotropy is generally \textless~0.1 s and the raypath difference is generally \textless20 km. Two models of Vp radial anisotropy tomography under Japan are obtained using the isotropic and anisotropic ray tracing codes. The two models are very similar to each other, and they have only small differences (\textless0.5%) in the amplitudes of isotropic velocity and radial anisotropy. Considering the limited resolution of the current anisotropic tomography models and the effects of damping and smoothing regularizations, the use of the conventional isotropic ray tracing techniques is acceptable at this stage. However, for high-resolution models of anisotropic tomography in the near future, the 3-D anisotropic ray tracing will be necessary.

4. JGR

   \textitP Wave Anisotropic Tomography of the SE Tibetan Plateau: Evidence for the Crustal and Upper‐Mantle Deformations

   Zhouchuan Huang, Liangshu Wang, Mingjie Xu, and 1 more author

   Journal of Geophysical Research: Solid Earth, Oct 2018

   Abs URL

   The upper crust in the SE Tibetan Plateau is rotating around the eastern Himalayan syntax clockwise, and the western margin of the Yangtze Craton has been involved in the active tectonics. However, it is still unclear whether and how the deep crust and upper mantle respond to the plateau expansion. In this study we present a high-resolution three-dimensional model of P wave velocity tomography and azimuthal anisotropy in the crust and uppermost mantle beneath the SE Tibetan Plateau determined using traveltime data recorded by a dense seismic network. Widespread low-velocity zones are revealed around a high-velocity body in the deep crust and uppermost mantle beneath the southwest Yangtze Craton, where fast-velocity directions of the azimuthal anisotropy are mostly parallel to the contour lines of the surface topography and the Moho depth along the plateau margin. These results indicate that gravitational potential plays an important role in the crustal and uppermost-mantle deformations in the SE Tibetan Plateau. Meanwhile, the shallow crust may drop down to the deep crust and drive the ductile deep-crustal material to intrude into the adjacent regions. The extruded crust is trapped in a deep-crustal corner and obstructed by the surrounding strong blocks. The trapped crustal material may rise up, causing significant uplift and high heat flow at the surface.

2017

1. Mantle structure beneath the incipient Okavango rift zone in southern Africa

   Youqiang Yu, Kelly H. Liu, Zhouchuan Huang, and 5 more authors

   Geosphere, Feb 2017

   Abs URL

   Numerous investigations of the mature segments of the East African rift system (EARS) have significantly improved our understanding of the structure and processes associated with well-developed continental rifts. In contrast, knowledge of rifting processes at their early stage is still significantly limited. Here we present results from a teleseismic P-wave tomography investigation of the incipient Okavango rift zone (ORZ), which is located at the southwestern terminus of the EARS. P-wave relative travel-time residuals recorded by 17 recently deployed portable seismic stations were manually picked and inverted for three-dimensional upper-mantle and mantle transition-zone tomographic images beneath the ORZ and its adjacent areas. High-velocity anomalies probably representing cratonic lithosphere are visible under the Congo and Kalahari cratons, extending to depths of ~250–350 km. The tectonic boundary of the Congo craton is observed along the western edge of the ORZ. A localized low-velocity anomaly of about –1% in magnitude is revealed in the upper astheno­sphere beneath the ORZ, which is interpreted to represent decompression melting induced by lithospheric thinning. The results support the notion that the initiation and early-stage development of the ORZ are mostly due to lithospheric stretching resulted from the relative motion between the Archean Congo and Kalahari cratons along preexisting ancient orogenic zones.

2. EPSL

   Insight into NE Tibetan Plateau expansion from crustal and upper mantle anisotropy revealed by shear-wave splitting

   Zhouchuan Huang, Frederik Tilmann, Mingjie Xu, and 5 more authors

   Earth and Planetary Science Letters, Nov 2017

   URL

2016

1. SplitRFLab: A MATLAB GUI toolbox for receiver function analysis based on SplitLab

   Mijian Xu, Hui Huang, Zhouchuan Huang, and 1 more author

   Earthquake Science, Feb 2016

   Abs URL

   We add new modules for receiver function (RF) analysis in SplitLab toolbox, which includes the manual RF analysis module, automatic RF analysis and related quality control modules, and H-k stacking module. The updated toolbox (named SplitRFLab toolbox), especially its automatic RF analysis module, could calculate the RFs quickly and efficiently, which is very useful in RF analysis with huge amount of seismic data. China is now conducting the ChinArray project that plans to deploy thousands of portable stations across Chinese mainland. Our SplitRFLab toolbox may obtain reliable RF results quickly at the first time, which provide essentially new constraint to the crustal and mantle structures.

2. Crustal stress field in Yunnan: implication for crust-mantle coupling

   Zhigang Xu, Zhouchuan Huang, Liangshu Wang, and 6 more authors

   Earthquake Science, Apr 2016

   URL

2015

1. Two crustal low-velocity channels beneath SE Tibet revealed by joint inversion of Rayleigh wave dispersion and receiver functions

   Xuewei Bao, Xiaoxiao Sun, Mingjie Xu, and 9 more authors

   Earth and Planetary Science Letters, Apr 2015

   URL
2. JGR

   \textitP wave tomography and anisotropy beneath Southeast Asia: Insight into mantle dynamics

   Zhouchuan Huang, Dapeng Zhao, and Liangshu Wang

   Journal of Geophysical Research: Solid Earth, Jul 2015

   Abs URL

   Southeast Asia is surrounded by subduction zones resulting from the interactions of several lithospheric plates. Its evolution has been also influenced by active tectonics due to the Indo-Asian collision in the Cenozoic. In this study, we use a large number of arrival-time data of local and regional earthquakes to determine 3-D P wave tomography and azimuthal anisotropy in the mantle beneath SE Asia. High-velocity (high-V) anomalies representing the subducting slabs are clearly visible in the upper mantle and the mantle transition zone (MTZ). Low-velocity (low-V) zones with trench-normal anisotropy are revealed in the uppermost mantle, which indicate back-arc spreading or secondary mantle-wedge flow induced by the slab subduction. In contrast, trench-parallel anisotropy dominates in the deep upper mantle and reflects structures either in the subducting slab or in the upper mantle surrounding the slab. The trench-parallel anisotropy is also significant in the lower MTZ, which may contribute to shear wave splitting observations. A low-V body extending down to the lower mantle is visible under the Hainan volcano far away from the plate boundaries, suggesting that Hainan is a hot spot fed by a lower-mantle plume. The low-V body under Hainan is connected with low-V zones in the upper mantle under SE Tibet and Vietnam. Our P wave anisotropy results reflect significant mantle flow existing in the asthenosphere from SE Tibet to Hainan and further southwestward to Vietnam. The present study, especially the 3-D P wave anisotropy results, provides important new insight into mantle dynamics in SE Asia.

3. JGR

   On the trade-off between seismic anisotropy and heterogeneity: Numerical simulations and application to Northeast Japan

   Zhouchuan Huang, Dapeng Zhao, and Xin Liu

   Journal of Geophysical Research: Solid Earth, May 2015

   Abs URL

   P wave tomography has been recently used to study 3-D azimuthal and radial anisotropy of subduction zones and continental regions. However, the fundamental issue about the trade-off between the isotropic and anisotropic structures is still unclear. In this study, we investigate this issue systematically with comprehensive synthetic tests. Our results indicate that good ray coverage in the azimuth (for azimuthal anisotropy) and incidence (for radial anisotropy) is required for determining reliable anisotropic models. The isotropic and anisotropic structures are strongly coupled, and smearing effects are significant when the rays used in the inversion are limited in a small range of azimuth or incidence. We therefore plot ray azimuth and ray incidence ellipses at every grid nodes and propose to use the normalized length of the short axis (i.e., the ratio of the short-axis and long-axis lengths) for estimating the ray coverage quantitatively. Applying our novel approach to a large number of high-quality arrival time data of local shallow- and intermediate-depth earthquakes, we obtained new tomographic images of 3-D P wave azimuthal and radial anisotropy in Northeast Japan. Both the azimuthal and radial anisotropy results are determined reliably for the shallow parts of the study region, whereas the smearing effects are significant in the deeper part of the mantle wedge and the subducting slab. Our results show dominant trench-normal and vertical-fast anisotropy in the mantle wedge while trench-parallel and horizontal-fast anisotropy in the subducting slab, which indicates different dynamics in different domains of the subduction zone.

4. Teleseismic shear-wave splitting in SE Tibet: Insight into complex crust and upper-mantle deformation

   Zhouchuan Huang, Liangshu Wang, Mingjie Xu, and 6 more authors

   Earth and Planetary Science Letters, Dec 2015

   URL
5. EPSL

   Mantle structure and dynamics beneath SE Tibet revealed by new seismic images

   Zhouchuan Huang, Pan Wang, Mingjie Xu, and 7 more authors

   Earth and Planetary Science Letters, Feb 2015

   URL

2014

1. Crustal structure beneath the Weihe Graben in central China: Evidence for the tectonic regime transformation in the Cenozoic

   Pan Wang, Zhouchuan Huang, Ning Mi, and 6 more authors

   Journal of Asian Earth Sciences, Feb 2014

   Abs URL

   In central China, Weihe Graben (WG) and its adjacent area suffered intensive compressional tectonics in the Paleozoic and the Mesozoic. Then, this region was dominated by extensional tectonics due to the farfield effect of the India–Eurasia collision in the Cenozoic. We deployed a portable broad-band seismic array in this region to investigate the crustal structure by using receiver functions. Integrated with regional geophysical and geological characteristics, the analysis of the receiver functions reveals that, the Moho is 32–37 km, 25–41 km, and 41 km depth beneath the northern Qinling terrane, the WG, and the southern margin of the Ordos block, respectively. The Moho depth increases beneath the southern boundary of the WG, while decreases \10–15 km beneath the northern boundary of the WG. The Moho discontinuity beneath the WG is not a fully mirror image of the crystalline basement, because the thickest sediments ($10 km) is in the south of the WG. The crustal structure in this region reveals how the crust responds to the tectonic regime transformation. The effect of the Cenozoic crustal extension was topdown. However, the Cenozoic crustal extension has limited effect on the Moho deformation. We suggested that the compressional tectonics before the Cenozoic dominated the lateral variation of the Moho. Ó 2013 Elsevier Ltd. All rights reserved.

2. Lateral Variations of the Mantle Transition Zone Structure beneath Eastern China

   H. Huang, P. Wang, N. Mi, and 5 more authors

   Bulletin of the Seismological Society of America, Jun 2014

   Abs URL

   The mantle transition zone (MTZ) structure beneath eastern China is studied by using P-wave receiver functions. The 410 km discontinuity is relatively flat whereas the depth of the 660 km discontinuity varies significantly under the study area. This indicates that the 660 is more influenced by laterally varying temperature. The 520 km discontinuity is continuously observed at ∼520 km depth under a limited area. Within the South China Block, the MTZ thickness under the Yangtze Craton is larger than normal whereas that under the Cathaysia Block is nearly normal. This indicates colder temperature affecting the MTZ beneath the Yangtze Craton. Combined with seismic tomography, our result suggests that the stagnant ancient slab beneath eastern China is mainly trapped around the base of the MTZ beneath the Yangtze Craton in the study area.

3. JGR

   Three-dimensional \textitP wave azimuthal anisotropy in the lithosphere beneath China: 3D P-wave anisotropy beneath China

   Zhouchuan Huang, Pan Wang, Dapeng Zhao, and 2 more authors

   Journal of Geophysical Research: Solid Earth, Jul 2014

   Abs URL

   Seismic anisotropy in the upper mantle beneath East Asia has been studied extensively using shear wave (SKS) splitting measurements, which have provided important information on mantle dynamics in this region. However, SKS measurements have poor vertical resolution, and so their interpretations are usually not unique. In this work we use a large number of traveltime data from 34,036 local earthquakes recorded by 1563 seismic stations to determine the first model of 3-D P wave azimuthal anisotropy in the lithosphere beneath China. Our results show that the fast velocity directions (FVDs) are generally correlated with the surface geologic features, such as the strikes of the orogens, active faults, and tectonic boundaries. The FVDs in the upper crust are normal to the maximal horizontal stress (σH) in regions with extensive compression such as the Tibetan Plateau, whereas they are subparallel to σH in strike-slip shear zones such as the western and eastern Himalayan syntax. The comparison of the FVDs of P wave anisotropy with SKS splitting measurements indicates that beneath the Tibetan Plateau the seismic anisotropy in the lithosphere contributes significantly to the SKS splitting observations. In contrast, in east China the P wave FVDs in the lithosphere are different from the SKS splitting measurements, suggesting that the SKS splitting is mainly caused by the anisotropy in the deeper mantle such as the asthenosphere and the mantle transition zone under east China. These novel results provide important new information on the lithospheric deformation and mantle dynamics in East Asia.

2013

1. Aseismic deep subduction of the Philippine Sea plate and slab window

   Zhouchuan Huang, Dapeng Zhao, Akira Hasegawa, and 3 more authors

   Journal of Asian Earth Sciences, Oct 2013

   Abs URL

   We have made great efforts to collect and combine a large number of high-quality data from local earthquakes and teleseismic events recorded by the dense seismic networks in both South Korea and West Japan. This is the first time that a large number of Korean and Japanese seismic data sets are analyzed jointly. As a result, a high-resolution 3-D P-wave velocity model down to 700-km depth is determined, which clearly shows that the Philippine Sea (PHS) plate has subducted aseismically down to $460 km depth under the Japan Sea, Tsushima Strait and East China Sea. The aseismic PHS slab is visible in two areas: one is under the Japan Sea off western Honshu, and the other is under East China Sea off western Kyushu. However, the aseismic PHS slab is not visible between the two areas, where a slab window has formed. The slab window is located beneath the center of the present study region where many teleseismic rays crisscross. Detailed synthetic tests were conducted, which indicate that both the aseismic PHS slab and the slab window are robust features. Using the teleseismic data recorded by the Japanese stations alone, the aseismic PHS slab and the slab window were also revealed (Zhao et al., 2012), though the ray paths in the Japanese data set crisscross less well offshore. The slab window may be caused by the subducted Kyushu-Palau Ridge and Kinan Seamount Chain where the PHS slab may be segmented. Hot mantle upwelling is revealed in the big mantle wedge above the Pacific slab under the present study region, which may have facilitated the formation of the PHS slab window. These novel findings may shed new light on the subduction history of the PHS plate and the dynamic evolution of the Japan subduction zone.

2. Relocating the 2011 Tohoku-oki earthquakes (M 6.0–9.0)

   Zhouchuan Huang, and Dapeng Zhao

   Tectonophysics, Feb 2013

   Abs URL

   The great Tohoku-oki earthquake (Mw 9.0) on 11 March 2011 was accompanied by nearly 100 large foreshocks and aftershocks (M ≥ 6.0) in the Northeast Japan forearc. In this study we relocated 77 of these large events using three different velocity models. An updated three-dimensional velocity model significantly reduced the travel-time residuals in the earthquake relocation. We found that the large thrust earthquakes are generally located in or around high-velocity patches, suggesting that the generation of the large thrust earthquakes is controlled by structural heterogeneities in the megathrust zone. The high-velocity patches may represent asperities in the megathrust zone where the subducting Pacific plate and the overriding Okhotsk plate may be coupled strongly. Many non-thrust earthquakes occurred in the crust of the overriding Okhotsk plate, indicating that the stress field there has been changed by the Tohoku-oki mainshock. The present results may improve our understanding of the subduction dynamics and seismotectonics of the Northeast Japan arc.

3. JAES

   Mechanism of the 2011 Tohoku-oki earthquake (Mw 9.0) and tsunami: Insight from seismic tomography

   Zhouchuan Huang, and Dapeng Zhao

   Journal of Asian Earth Sciences, Jul 2013

   Abs URL

   To clarify the generating mechanism of the 2011 Tohoku-oki earthquake (Mw 9.0) and the induced tsunami, we determined high-resolution tomographic images of the Northeast Japan forearc. Significant lateral variations of seismic velocity are visible in the megathrust zone, and most large interplate thrust earthquakes are found to occur in high-velocity (high-V) areas. These high-V zones may represent high-strength asperities at the plate interface where the subducting Pacific plate and the overriding Okhotsk plate are coupled strongly. A shallow high-V zone with large coseismic slip near the Japan Trench may account for the mainshock asperity of the 2011 Tohoku-oki earthquake. Because it is an isolated asperity surrounded by low-velocity patches, most stress on it was released in a short time and the plate interface became decoupled after the Mw 9.0 earthquake. Thus the overriding Okhotsk plate there was shot out toward the Japan Trench and caused the huge tsunami.

4. Mapping P-wave azimuthal anisotropy in the crust and upper mantle beneath the United States

   Zhouchuan Huang, and Dapeng Zhao

   Physics of the Earth and Planetary Interiors, Dec 2013

   Abs URL

   Much progress has been made on revealing seismic structure and mantle dynamics beneath the United States (US) with the EarthScope/USArray project. Seismic anisotropy revealed by shear-wave splitting studies provides important constraints on constructing geodynamic models with regard to the seismic images, but the shear-wave splitting observations have poor vertical resolution and so their interpretations are often not unique. In this work we used a large number of arrival-time data from local and distant earthquakes recorded by the USArray to determine the first P-wave azimuthal anisotropy tomography of the crust and upper mantle beneath the US. Our results show that fast velocity directions (FVDs) in the lithosphere under the tectonically active areas correlate well with the surface tectonic features, suggesting that the P-wave anisotropy mainly reflects the present deformation. A circular pattern of the FVDs centered in the Great Basin is revealed, which is well consistent with the specific circular shear-wave splitting observations there, suggesting that the anisotropy occurs in the crust and uppermost mantle. In contrast, beneath the stable cratonic region, the FVDs revealed by this study differ from the shear-wave splitting observations but consistent with the features of gravity and magnetic anomalies, indicating that the P-wave FVDs mainly reflect the fossil anisotropy in the lithosphere, whereas the Swave splitting observations mainly reflect the significant anisotropy in the asthenosphere. The present results shed new light on the seismic anisotropy in the crust and upper mantle and provide new constraints on constructing geodynamic models beneath the US.

5. Distinct lateral variations of upper mantle anisotropy beneath eastern China revealed by shear-wave splitting

   Hui Huang, Mingjie Xu, Liangshu Wang, and 5 more authors

   Geochemistry, Geophysics, Geosystems, Jun 2013

   URL

2011

1. EPSL

   Seismic anisotropy and mantle dynamics beneath China

   Zhouchuan Huang, Liangshu Wang, Dapeng Zhao, and 2 more authors

   Earth and Planetary Science Letters, Jun 2011

   Abs URL

   We analyzed the shear-wave splitting at 138 permanent seismograph stations to study seismic anisotropy and mantle dynamics under Mainland China. To obtain reliable results we used three different methods to measure the shear-wave splitting parameters using core phases (SKS, SKKS, SKiKS and PKS) as well as the direct S waves from regional and distant earthquakes. Our results show that the fast orientations of the anisotropy (WNW–ESE) in eastern China are generally consistent with the absolute plate motion (APM) direction of the Eurasian plate, suggesting that the anisotropy is mainly located in the asthenosphere resulting from the lattice-preferred orientation of olivine due to the shear deformation there. The fast axes in western China generally agree with the strikes of the orogens and active faults, while they are perpendicular to the direction of the maximum horizontal stress, suggesting that the anisotropy in the lithosphere contributes significantly to the observed shear-wave splitting. The fast axes in western China are also consistent with the APM direction, suggesting that the APM-driven anisotropy in the asthenosphere is another source of the shear-wave splitting there. These results suggest that APM-driven anisotropy commonly exists under continents, similar to that under oceanic regions, even though the continental lithosphere has suffered extensive deformation.

2. GJI

   Seismic heterogeneity and anisotropy of the Honshu arc from the Japan Trench to the Japan Sea: Heterogeneity and anisotropy of Honshu arc

   Zhouchuan Huang, Dapeng Zhao, and Liangshu Wang

   Geophysical Journal International, Mar 2011

   Abs URL

   Most Popular Paper

   We determined P- and S-wave tomography and P-wave anisotropic structure under the Honshu arc from the Japan Trench to the backarc area under the Japan Sea using 310 749 P- and 150 563 S-wave arrivals from 4655 local earthquakes recorded by 982 seismograph stations. Arrival times from 1451 suboceanic earthquakes relocated with sP depth phases enable us to determine the structures under the Pacific Ocean and Japan Sea, which expand the study region from the land area to the whole arc from the Japan Trench to the Japan Sea with a width of more than 500 km. The results show strong heterogeneities above the subducting Pacific slab under the Pacific Ocean and most large thrust-type earthquakes occurred in the high-velocity areas where the Pacific slab and the overriding continental plate may be strongly coupled. Low-velocity (low-V ) zones are imaged in the mantle wedge with significant along-arc variations under the volcanic front. The mantle-wedge low-V zone extends westwards under the Japan Sea and it is connected with the subducting Pacific slab at depths of 150–200 km under the backarc. The results indicate that the H2O and fluids brought downwards by the subducting Pacific slab are released into the mantle wedge by dehydration and are subsequently transported to the surface by the upwelling flow in the mantle wedge. Significant P-wave anisotropic anomalies are revealed under the Honshu arc. The predominant fast velocity direction (FVD) is E–W in the mantle wedge while it is N–S in the subducting Pacific slab. The anisotropy in the mantle wedge is the result of deformation caused by the subduction of the Pacific plate and the induced mantle-wedge convection, while the FVD pattern in the middle of the mantle wedge argues for the 3-D mantle flow or the specific alignment of the olivine in the partial-melting mantle. The N–S (trench-parallel) FVD in the subducting Pacific slab represents either the original fossil anisotropy when the Pacific plate formed or the trench-parallel crystallographic and shaped preferred orientation in the subducting slab due to the slab bending. The present results shed new light on the structural heterogeneities and seismic anisotropy under the Honshu arc, which may improve our understanding of the dynamic processes of subduction zones.

3. Seismic imaging of the Amur–Okhotsk plate boundary zone in the Japan Sea

   Dapeng Zhao, Zhouchuan Huang, Norihito Umino, and 2 more authors

   Physics of the Earth and Planetary Interiors, Sep 2011

   Abs URL

   We determined high-resolution images of P and S wave velocity and Poisson’s ratio under the Japan Sea off Honshu Island using a large number of arrival-time data from local earthquakes to understand the interaction of the Amur and Okhotsk plates. Our new data collected from the crustal earthquakes under the Japan Sea relocated precisely with sP depth phase are crucial to make this work possible. Our results show that strong lateral heterogeneities exist in the crust and upper mantle under the Amur–Okhotsk plate boundary zone, which may have affected the seismotectonics in the region. The crustal velocity variations under the Japan Sea may reflect the complicated geologic structures that were produced during the opening of the Japan Sea and the present compressional stage of the Honshu arc associated with the collision of the Amur plate with the Okhotsk plate. Low-velocity zones in the mantle wedge are found to extend westward under the Japan Sea, rather than just confined under Honshu Island, suggesting that the back-arc magmatism and tectonics are part of the complex geodynamic system in East Asia.

4. Frequency-dependent shear-wave splitting and multilayer anisotropy in northeast Japan

   Zhouchuan Huang, Dapeng Zhao, and Liangshu Wang

   Geophysical Research Letters, Apr 2011

   URL
5. G-cubed

   Shear wave anisotropy in the crust, mantle wedge, and subducting Pacific slab under northeast Japan

   Zhouchuan Huang, Dapeng Zhao, and Liangshu Wang

   Geochemistry, Geophysics, Geosystems, Jan 2011

   URL
6. Stress field in the 2008 Iwate-Miyagi earthquake (M7.2) area

   Zhouchuan Huang, Dapeng Zhao, and Liangshu Wang

   Geochemistry, Geophysics, Geosystems, Jun 2011

   URL
7. 利用天然地震研究地球内部结构与动力学：以中国大陆和东北日本为例

   黄周传

   南京大学, Jun 2011
8. Structural heterogeneity in the megathrust zone and mechanism of the 2011 Tohoku-oki earthquake (Mw 9.0): THE 2011 TOHOKU-OKI EARTHQUAKE (Mw 9.0)

   Dapeng Zhao, Zhouchuan Huang, Norihito Umino, and 2 more authors

   Geophysical Research Letters, Sep 2011

   URL

2010

1. 

   Upper mantle structure and dynamics beneath Southeast China

   Zhouchuan Huang, Liangshu Wang, Dapeng Zhao, and 5 more authors

   Physics of the Earth and Planetary Interiors, Oct 2010

   Abs Bib URL Website Demo

   We applied teleseismic tomography to 5671 relative travel-time residuals from 257 teleseismic events recorded by 69 seismic stations to determine the 3D P-wave velocity structure of the upper mantle under Southeast (SE) China. Our results show prominent low P-wave velocity (low-Vp) anomalies under SE China which may reflect the remnant magma chambers and channels of the Late Mesozoic igneous rocks, which may be reheated by the upwelling mantle flow from the lower mantle driven by the deep subduction in East Asia during the Cenozoic. High-Vp anomalies are revealed in the upper mantle to the east of Taiwan, which represent the subducted Eurasian plate. Our result also suggests the break-off of the subducted Eurasian plate caused by its interaction with the Philippine Sea plate under Central and North Taiwan. The slab break-off may have created a mantle window through which the asthenospheric flow arises, causing the high heat flow and rapid uplift in the Taiwan orogen.

   @article{huang_upper_2010,
     title = {Upper mantle structure and dynamics beneath Southeast China},
     volume = {182},
     issn = {00319201},
     url = {https://linkinghub.elsevier.com/retrieve/pii/S0031920110001524},
     demo = {https://linkinghub.elsevier.com/retrieve/pii/S0031920110001524},
     doi = {10.1016/j.pepi.2010.07.010},
     language = {en},
     number = {3-4},
     urldate = {2022-08-10},
     journal = {Physics of the Earth and Planetary Interiors},
     author = {Huang, Zhouchuan and Wang, Liangshu and Zhao, Dapeng and Xu, Mingjie and Mi, Ning and Yu, Dayong and Li, Hua and Li, Cheng},
     month = oct,
     year = {2010},
     pages = {161--169},
   }

2. P-wave tomography, anisotropy and seismotectonics in the eastern margin of Japan Sea

   Zhouchuan Huang, Dapeng Zhao, Norihito Umino, and 4 more authors

   Tectonophysics, Jun 2010

   Abs URL

   To understand the seismotectonics in the eastern margin of the Japan Sea, we determined the first highresolution 3-D P-wave velocity structure and azimuthal anisotropy under the Japan Sea off Northeast Japan using 175,425 high-precision P-wave arrival times from 2833 local earthquakes recorded by 330 seismograph stations. P-wave arrival times from 145 suboceanic earthquakes relocated with sP depth phase are crucial to determine the structure of the crust and uppermost mantle under the Japan Sea. Our results show that strong velocity variations exist in the crust and uppermost mantle under the eastern margin of the Japan Sea. Many large crustal earthquakes occurred in or around low-velocity zones which may represent weak sections of the seismogenic crust. The P-wave azimuthal anisotropy is complex under the Japan Sea, which may also indicate the complex crustal structures there. In the eastern margin of the Japan Sea, the strong heterogeneities in the crust and upper mantle revealed by seismic tomography may reflect the complicated geologic structures such as the alternate rift zones, ridges, basins, horsts, grabens, volcanics, and continental fragments which were produced during the back-arc spreading, opening of the Japan Sea and the present compressional stage of the Honshu arc.

2008

1. GRL

   Shear wave splitting in the southern margin of the Ordos Block, north China

   Zhouchuan Huang, Mingjie Xu, Liangshu Wang, and 3 more authors

   Geophysical Research Letters, Oct 2008

   URL

2007

1. 贝加尔裂谷带中部的新构造特征及其成因分析

   黄周传,  邹付戈,  盛玲, and 2 more authors

   华东地质, Oct 2007
2. Shear wave splitting across the Ailao Shan-Red River fault zone, SW China

   Zhouchuan Huang, Liangshu Wang, Mingjie Xu, and 3 more authors

   Geophysical Research Letters, Oct 2007

   URL