Article
Geochemistry & Geophysics
Yan Lu, Juan Li, Yuhui He, Lian-Feng Zhao, Jinhai Zhang
Summary: This study constructed the first Pn velocity and anisotropy model of the uppermost mantle in Central and Northwestern South America. The results showed significantly low Pn velocities and arc-parallel anisotropic structures beneath the volcanic arc in Central America. Furthermore, a separate, low Pn velocity was observed beneath a back-arc volcano in Nicaragua, indicating the separation of hot material upwelling in the uppermost mantle beneath this volcano from the main volcanic arc. Additionally, the stable Caribbean Plate exhibited high Pn velocities.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Yan Lu, Jiaqi Liu, Yuhui He, Yurui Guan
Summary: The study reveals that the anisotropic structure of the uppermost mantle in the collisional plate boundary area in eastern Caribbean is the main cause of shear-wave splitting, and the seismic velocity beneath the Aves Ridge is not anomalous, indicating a lack of mantle material upwelling influence. High Pn velocities are observed in the uppermost mantle below the eastern Caribbean Sea, suggesting minimal to no impact from hot material from the deeper mantle in the back-arc region.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
I Palomeras, P. Ayarza, J. Andres, A. M. Alvarez-Valero, J. Gomez-Barreiro, J. Diaz, J. Alcalde, R. Carbonell
Summary: Multiple sub-Moho reflectors have been identified through seismic experiments in western Iberia since the early 1990s, with the shallowest event likely corresponding to a positive velocity contrast related to the lithosphere-asthenosphere boundary.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Fenitra Andriampenomanana, Andrew A. Nyblade, Michael E. Wysession, Raymond J. Durrheim, Frederik Tilmann, Guilhem Barruol, Gerard Rambolamanana, Tsiriandrimanana Rakotondraibe
Summary: The lithosphere of Madagascar has undergone a long series of tectonic processes, from the Pan-African Orogeny to extensional tectonic and magmatic events. Studies show complex lateral variations in seismic velocity and anisotropy within the uppermost mantle, reflecting the tectonic history and thermal perturbations.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Chuanming Liu, Shane Zhang, Anne F. F. Sheehan, Michael H. H. Ritzwoller
Summary: Comprehensive observations of surface wave anisotropy are conducted across Alaska and the Aleutian subduction zone to improve understanding of its tectonics, mantle dynamics, and earthquake risk. Using data from various sources, including earthquakes and ambient noise, researchers create tomographic maps that provide insights into the crustal and uppermost mantle structure of the region.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geosciences, Multidisciplinary
Shengzhong Zhang, Bing Zhang, Ming Zhou, Longbin Ouyang
Summary: By collecting seismic data and applying a joint inversion technique, this study successfully reveals the crustal and upper mantle structure beneath the Tien Shan and its adjacent areas. The results show significant heterogeneities in both crust thickness and S wave velocity, indicating the important role of the collision between Eurasian plate and Indian plate in the tectonic activity of the region. The apparent velocity heterogeneities in the northern Tarim Basin suggest erosion and damage caused by upwelling hot materials from the upper mantle.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Geochemistry & Geophysics
Lili Feng
Summary: The study presents a 3-D isotropic shear wave velocity model of the crust and uppermost mantle beneath the Alaska-Aleutian subduction zone, based on seismic data recorded by the Alaska Amphibious Community Seismic Experiment (AACSE) array and other networks. The model is derived from Rayleigh wave phase speed measurements extracted from ambient seismic noise and a new three-station interferometry approach. A Bayesian Monte Carlo inversion is performed to produce the shear wave velocity model, capturing prominent structures and geological features related to subduction zone dynamics. The Vs reduction near the Shumagin gap is observed, consistent with previous studies on the hydration of the oceanic plate and local seismicity variation.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
Qingya Tang, Weijia Sun, Kazunori Yoshizawa, Li-Yun Fu
Summary: This study developed a radially anisotropic 3-D shear-wave model of the South China Block using multimode surface wave tomography, revealing distinctive structural contrasts in the Cathaysia Block and the Yangtze Craton, as well as abrupt changes in radial anisotropy beneath the Sichuan Basin and negative radial anisotropy beneath Hainan Island and its surroundings.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Mingye Feng, Ling Chen, Shengji Wei, Xin Wang, Xu Wang, Zimu Wu
Summary: Researchers developed a new method called Dip Direction Searching (DDS) to estimate the dip direction of slabs more accurately. The method was used in the Sumatran subduction zone and provided important insights into the thickness and dip direction of the slabs in that area.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Astronomy & Astrophysics
Genti Toyokuni, Dapeng Zhao
Summary: The study presents the first 3-D images of P-wave radial anisotropy (RAN) and azimuthal anisotropy (AAN) beneath Greenland and surrounding regions down to 750-km depth. The findings reveal varied mantle structures and tectonic evolutions in different regions, supporting theoretical explanations for regional breakup processes.
EARTH AND SPACE SCIENCE
(2021)
Article
Geochemistry & Geophysics
Lili Feng, Jordi Diaz
Summary: Using a large seismic dataset, a high-resolution Earth model is constructed to investigate the crustal and mantle structure and tectonic evolution history of the westernmost Mediterranean. Radial anisotropy anomalies are mapped for the first time, providing valuable insights into the dynamic evolution of the region.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Lili Feng, Jordi Diaz
Summary: This study uses seismic data to construct a high-resolution 3-D model of the western Mediterranean, revealing the characteristics of the crust and mantle in the region. By studying the radial anisotropy anomalies, it helps improve the understanding of the tectonic evolution history.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Wu YiYing, Deng SiZhuang, Niu FengLin, He Wei, Wu HanNing
Summary: The Qinling Orogenic Belt is an east-west extended Proterozoic mountain range with overall E-W fast polarization direction of seismic anisotropy. However, there are slight variations at its western and eastern ends, and significant difference in fast polarization direction between crust and upper mantle deformation in the eastern part of the belt.
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
(2021)
Article
Geochemistry & Geophysics
Lun Li, Xuezhen Zhang, Jie Liao, Yanling Liang, Shixian Dong
Summary: The study reveals the presence of a weak mid-to-lower crust in Tibet, potentially flowing towards the southeastern region, while this crustal flow is absent in the Qinling orogen. This weak mid-to-lower crust can decouple the upper crust and lower crust/upper mantle, accommodating active deformation in response to the Indian-Asian convergence.
Article
Geochemistry & Geophysics
Lei Shi, Yonghua Li, Weilai Wang, Yawei Ma
Summary: The northeastern margin of the Tibetan Plateau exhibits decreasing crustal thickness and a low Vp/Vs ratio, indicating felsic crustal composition. Deviations from isostatic equilibrium are observed beneath certain terranes, and the correlation between elevation and crustal thickness is weak, suggesting contributions from both the crust and lithospheric mantle to isostatic compensation. Anti-correlations between crustal thickness and Vp/Vs ratio and density support the hypothesis of upper-crust thickening or lower-crust delamination in the northeastern Tibetan Plateau.
Article
Geochemistry & Geophysics
L. Feng, Chuanming Liu, M. H. Ritzwoller
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2020)
Article
Geochemistry & Geophysics
Lili Feng
Summary: The study presents a 3-D isotropic shear wave velocity model of the crust and uppermost mantle beneath the Alaska-Aleutian subduction zone, based on seismic data recorded by the Alaska Amphibious Community Seismic Experiment (AACSE) array and other networks. The model is derived from Rayleigh wave phase speed measurements extracted from ambient seismic noise and a new three-station interferometry approach. A Bayesian Monte Carlo inversion is performed to produce the shear wave velocity model, capturing prominent structures and geological features related to subduction zone dynamics. The Vs reduction near the Shumagin gap is observed, consistent with previous studies on the hydration of the oceanic plate and local seismicity variation.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
Lili Feng
Summary: This study presents a high-resolution 3-D Vs model of the crust and uppermost mantle beneath central Mongolia, constructed using a Bayesian Monte Carlo inversion method that interprets Rayleigh wave phase speeds and receiver functions. The model captures prominent geological and tectonic features, including high-speed anomalies in the upper crust, relatively thick crust beneath certain regions, high-velocity anomalies beneath volcanic fields, and low-velocity anomalies in the mantle indicating possible partial melting locations.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Lili Feng, Jordi Diaz
Summary: A high-resolution azimuthally anisotropic Vs model beneath the westernmost Mediterranean is constructed based on Rayleigh wave dispersions obtained from seismic stations. The model reveals consistent anisotropy with the analysis of SKS splitting, vertically coherent mantle deformation, and complex anisotropy in the Alboran Basin related to mantle flow pattern.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)