Article
Geosciences, Multidisciplinary
Yongfei Zheng, Yixiang Chen, Renxu Chen, Liqun Dai
Summary: This article discusses the changes in the dynamic regime and geothermal gradient of subduction zones at convergent plate boundaries in different stages, as well as the types of metamorphism and magmatism associated with them. These studies are of great significance for understanding the tectonic evolution of the Earth and the formation of rocks.
SCIENCE CHINA-EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Hwaju Lee, Younghee Kim, Maximiliano J. Bezada, Robert W. Clayton
Summary: This study compares the subduction of two ridges on the Nazca Plate and concludes that subslab mantle buoyancy has a larger impact on the subduction angle than the crustal material of the ridge.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Letter
Geosciences, Multidisciplinary
Ryan Porter, Mary Reid
Summary: The thermal regime of the continental lithosphere in North America was evaluated using seismic observations and lab results to estimate temperatures and lithospheric thickness, as well as predict melt distribution in the upper mantle. Results indicate thinner lithosphere and presence of melt in the western US, while thicker lithosphere with absence of melt is observed in the central and eastern US.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Ahmad B. Ahmad, Takeshi Tsuji
Summary: Plate subduction zones generate earthquakes and mountain building through plate collisions, forming complex structures and inducing mass transport like slumps. Advanced 3D seismic data collected in these zones can be analyzed with artificial intelligence techniques, such as convolutional neural networks (CNN), to automatically detect geological features like slump units and faults. The CNN model trained on specific subduction zone data showed high accuracy in identifying slump units and faults, demonstrating the potential for high-resolution geological structure investigation in other regions.
MARINE AND PETROLEUM GEOLOGY
(2021)
Review
Geochemistry & Geophysics
Rixiang Zhu, Guochun Zhao, Wenjiao Xiao, Ling Chen, Yanjie Tang
Summary: The origin, accretion, and reworking of the continental crust on Earth remain controversial. While plate tectonics theory struggles to explain the origin of Archean continents, growing evidence supports the oceanic plateau models as a better explanation. The characteristics of Archean continents, such as bimodal volcanics and the emplacement of TTG rocks, suggest a different geological process than plate tectonics.
REVIEWS OF GEOPHYSICS
(2021)
Article
Geochemistry & Geophysics
Arijit Laik, Wouter P. Schellart, Vincent Strak
Summary: This study investigates the effects of variations in density and rheological stratification on post-collisional convergence and collisional boundary migration in subduction and collision processes using numerical models. The results show that buoyancy of the colliding continent and viscosity of the overriding plate play important roles in driving convergence. Additionally, the sinking of the detached slab in the lower mantle induces whole mantle flow, sustaining slow convergence rates and preventing the residual slab from educting.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Zhiyong Yan, Lin Chen, Xiong Xiong, Bo Wan, Houze Xu
Summary: Research shows that oceanic plateaus play a key role in subduction zone reorganization, with different sizes and compositions leading to different subduction styles, including steep subduction, breakoff of subducting slab followed by flat-slab subduction, and subduction zone jump. These geodynamic results reveal the tectonic force switch in the overriding lithosphere during subduction zone reorganization, helping identify past subduction zone changes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geology
Keith Priestley, Tak Ho, Dan McKenzie
Summary: New evidence from seismic tomography indicates a unique mineral fabric in the thick mantle lithosphere beneath ancient continental cratons, shedding light on the formation of these structures. This mineral fabric, revealed through surface-wave tomography, suggests a vertical alignment of olivine crystals at depths of -150 km within cratonic continental-lithosphere roots, likely a remnant from craton formation. Geochemical and petrological studies further support the stability of cratonic mantle roots due to reduced density caused by melt removal at shallower depths. This seismological fabric at -150 km provides evidence of the shortening event that created the cratonic roots.
Article
Environmental Sciences
Caroline M. Eakin
Summary: Quasi-Love wave scattering is used to identify gradients in seismic anisotropy in the mantle beneath Australia, suggesting major lithospheric boundaries and modified mantle flow in the ocean-continent transition zone. The investigation reveals pervasive fossilized lithospheric anisotropy within the Australian continent, with lateral anisotropic gradients potentially indicating the edge of thick continental lithosphere or small-scale dynamic processes in the asthenosphere.
COMMUNICATIONS EARTH & ENVIRONMENT
(2021)
Article
Geochemistry & Geophysics
Ben S. Knight, J. Huw Davies, Fabio A. Capitanio
Summary: This study investigates the early stages of subduction using a numerical model, revealing the relationships between physical processes and parameters in the subduction zone, providing a detailed understanding of subduction processes.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Valerie Maupin, Alexandra Mauerberger, Frederik Tilmann
Summary: The study analyzes the radial anisotropy in the upper mantle of the Fennoscandian Shield using joint inversion of Love and Rayleigh wave phase velocities. Similar radial anisotropy is found in subregions down to at least 200 km depth, with SH waves faster than SV by 2%-3%. Different types of olivine crystallographic preferred orientations (CPOs) are discussed in relation to seismic observations.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geosciences, Multidisciplinary
Shengxian Liang, Xuben Wang, Zhengwei Xu, Yanpei Dai, Yonghua Wang, Jing Guo, Yanjie Jiao, Fu Li
Summary: In this paper, the distribution of residual gravity anomalies in the upper mantle of southern Tibet is estimated using the gravity data and seismic velocity models, and the heterogeneous density distribution of the upper-mantle is then recovered through three-dimensional gravity inversion. The results reveal a low-density anomaly in the upper mantle under the eastern Himalaya, while there is no obvious density anomaly under the western Himalaya. This observation indicates that the tearing and the steep subduction of the Indian continental mantle lithosphere might be associated with the magmatic and mineralization events in the eastern Himalaya-Gangdese and the formation of the Yadong-Gulu Rift.
SCIENCE CHINA-EARTH SCIENCES
(2023)
Article
Geochemistry & Geophysics
Pousali Mukherjee, Kajaljyoti Borah, Alok Yadav
Summary: This study models receiver functions to investigate the crustal structures of the Precambrian Gondwanaland, finding variations in crustal thickness and composition among different cratons of different ages. The separation of Gondwana led to crustal delamination and destruction of thick crustal roots. Episodic cycles of crustal growth are also observed.
Article
Geochemistry & Geophysics
Irena Miladinova, Walter Kurz, Thomas Hilmbauer-Hofmarcher
Summary: Active serpentinite mud volcanoes in the forearc region of the Izu-Bonin-Mariana system provide valuable insights into the processes along convergent plate margins. The recovered samples from the expedition indicate different degrees of serpentinization and alteration, with lower temperatures and higher degrees of alteration closer to the trench. The detailed characterization of fluid-rock interactions and mass transfers in subduction zones is important for understanding serpentinite fault gouge and mudflow emplacement.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Geochemistry & Geophysics
Mario D'Acquisto, Taco Broerse, Celine P. Marsman, Rob Govers
Summary: We analyzed the results of GNSS measurements with sub-meter accuracy in South America, Southeast Asia, and northern Japan to understand the deformation of overriding plates during megathrust earthquakes. Our findings show that interseismic velocities decrease with distance from the trench, reaching a hurdle where the gradient becomes lower and velocities are small. These hurdles are located 500-1000 km away from the trench and are associated with significant coseismic displacements during major earthquakes. Finite element models of the earthquake cycle suggest that the hurdles result from a contrast in the mechanical properties of the overriding plate, with a stiffer plate beyond the hurdler. Previous studies have found major tectonic or geological boundaries near these observed hurdles, indicating their significance.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
K. Hamada, K. Yoshizawa
GEOPHYSICAL JOURNAL INTERNATIONAL
(2015)
Article
Geochemistry & Geophysics
Yuki Nakashima, Kosuke Heki, Akiko Takeo, Mokhamad N. Cahyadi, Arif Aditiya, Kazunori Yoshizawa
EARTH AND PLANETARY SCIENCE LETTERS
(2016)
Correction
Geochemistry & Geophysics
K. Hamada, K. Yoshizawa
GEOPHYSICAL JOURNAL INTERNATIONAL
(2018)
Review
Geochemistry & Geophysics
B. L. N. Kennett, K. Yoshizawa, T. Furumura
Article
Geochemistry & Geophysics
Takehi Isse, Hitoshi Kawakatsu, Kazunori Yoshizawa, Akiko Takeo, Hajime Shiobara, Hiroko Sugioka, Aki Ito, Daisuke Suetsugu, Dominique Reymond
EARTH AND PLANETARY SCIENCE LETTERS
(2019)
Article
Geochemistry & Geophysics
H. Matsuzawa, K. Yoshizawa
GEOPHYSICAL JOURNAL INTERNATIONAL
(2019)
Article
Geochemistry & Geophysics
Masaki Yoshida, Saneatsu Saito, Kazunori Yoshizawa
Article
Geochemistry & Geophysics
Toru Taira, Kazunori Yoshizawa
GEOPHYSICAL JOURNAL INTERNATIONAL
(2020)
Article
Geochemistry & Geophysics
Masaki Yoshida, Saneatsu Saito, Kazunori Yoshizawa
Review
Astronomy & Astrophysics
Masaki Yoshida, Kazunori Yoshizawa
Summary: The influence of the continental lithosphere and its root on the continental drift is crucial in plate tectonics history, with stability determined by the viscosity contrast between the continental lithosphere and the underlying mantle. Orogenic belts or suture zones surrounding cratons act as a buffer to protect cratons and ensure longevity. The presence of low-viscosity asthenosphere reduces basal drag force, contributing to the stability and longevity of the cratonic lithosphere.
ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES, VOL 49, 2021
(2021)
Article
Geochemistry & Geophysics
M. G. Brown, G. Lin, H. Matsuzawa, K. Yoshizawa
Summary: Time-warping is a signal processing technique that isolates and extracts contributions from individual mode numbers in an isolated measurement of a transient signal propagating in a waveguide, and recovers dispersion curves for each mode number.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
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
Kotaro Tarumi, Kazunori Yoshizawa
Summary: The explosive eruption at Hunga Tonga-Hunga Ha'apai on January 15, 2022 generated atmospheric waves, meteotsunamis, tsunamis, and seismic waves recorded worldwide. Using back-projection analysis of teleseismic P-waves, the study successfully detected the locations and timing of multiple explosions. The results suggest that the eruption cycle may be synchronized with the eigen-period of the atmosphere-lithosphere coupled mode.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Sanxi Ai, Takeshi Akuhara, Manabu Morishige, Kazunori Yoshizawa, Masanao Shinohara, Kazuo Nakahigashi
Summary: The formation of a new ocean basin provides a unique observational window into the structure and deformation of the oceanic lithosphere. This study offers a detailed 1-D vertically polarized shear-wave velocity model of the young Japan Basin by interpreting S receiver functions, seafloor Rayleigh wave ellipticities and phase velocities in a Bayesian trans-dimensional framework. The analysis reveals distinct lithospheric discontinuity and layers, suggesting an important role of small-scale convection in modifying the structural fabrics and radial anisotropy.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Environmental Sciences
Takehi Isse, Daisuke Suetsugu, Akira Ishikawa, Hajime Shiobara, Hiroko Sugioka, Aki Ito, Yuki Kawano, Kazunori Yoshizawa, Yasushi Ishihara, Satoru Tanaka, Masayuki Obayashi, Takashi Tonegawa, Junko Yoshimitsu
Summary: Research shows that the lithosphere-asthenosphere boundary beneath the Ontong Java Plateau is approximately 40 km deeper than beneath the surrounding seafloor, suggesting it has deepened due to the underplating of dehydrated material during the formation of the plateau by a thermochemical mantle plume. Analysis indicates that the lithosphere beneath the Ontong Java Plateau is thickened by up to 40 km compared to the surrounding ocean floor, indicating it formed through the ascent of a mantle plume.
COMMUNICATIONS EARTH & ENVIRONMENT
(2021)