Crustal Seismology and Upper Mantle Structure in Eastern Asia

Eastern Asia accommodates a mosaic of cratonic blocks, orogenic belts and active continental margins whose interactions have shaped the present‐day lithosphere. Crustal seismology using receiver functions, wide‐angle reflection–refraction profiles and ambient noise tomography has delineated Moho depths varying from 25 km beneath extensional basins to over 45 km beneath collisional orogens. Shear‐wave radial anisotropy reveals mid‐crustal channels aligned with mineral fabrics formed during Mesozoic extension, while P‐wave velocity models image lithospheric thinning to less than 70 km beneath eastern craton margins. Seismic evidence for buried sutures between the Yangtze and Cathaysia blocks points to preserved Gondwanan terranes, and high‐velocity anomalies at 90–150 km depth beneath South China testify to episodes of lithospheric delamination and relamination. Mantle upwelling associated with Pacific plate subduction and discrete mantle plume activity beneath Hainan Island further modulates magmatism and geothermal flux. Such integrated structural insights are essential for seismic hazard assessment, resource exploration and reconstructing the geodynamic evolution of this tectonically active region.

Research from Nature Portfolio

Recent seismic imaging has uncovered tabular high‐velocity anomalies at depths of 90–150 km beneath the convergent belt between the Yangtze and Cathaysia blocks, interpreted as delaminated lower lithosphere that has since relaminated, shedding light on Mesozoic magmatic provinces in South China. Magnetotelluric profiling has revealed NE–SW oriented conductive interfaces subdividing eastern South China into six microcontinental segments, supporting a multi‐terrane accretion–collision model for block assembly. Foundational receiver‐function analyses across the Jiangnan orogenic belt have defined a deep geosuture between the Yangtze and Cathaysia blocks, characterised by contrasting crustal compositions and seismic structures consistent with Gondwanan fragments.

Crustal Seismology and Upper Mantle Structure in Eastern Asia publication trend

The graph below shows the total number of articles in crustal seismology and upper mantle structure in eastern asia across all publications each year (not limited to Nature Index journals).

Technical terms

Lithospheric delamination: The process by which dense lower lithospheric mantle detaches and sinks into the asthenosphere.

Ambient noise tomography: Seismic imaging technique using background seismic noise to extract surface‐wave velocity structure.

Receiver function: Analysis of converted seismic phases (P to S or S to P) to image subsurface discontinuities like the Moho.

Radial anisotropy: Variation in shear‐wave velocity between horizontally and vertically polarised waves, indicating mineral alignment or stress orientation.

Geosuture: A former collisional boundary between distinct crustal blocks now preserved as a seismic and compositional discontinuity.

References

1. Seismically imaged lithospheric delamination and its controls on the Mesozoic Magmatic Province in South China. Nature Communications (2023).
2. A Mid‐Crustal Channel of Positive Radial Anisotropy Beneath the Eastern South China Block From F‐J Multimodal Ambient Noise Tomography. Geophysical Research Letters (2024).
3. Seismic Evidence for a Geosuture between the Yangtze and Cathaysia Blocks, South China. Scientific Reports (2013).
4. Magnetotelluric evidence for the multi-microcontinental composition of eastern South China and its tectonic evolution. Scientific Reports (2020).
5. Integrated Geophysical Study of the Collision Between the North China Craton and the Yangtze Craton and Its Links With Craton Lithospheric Thinning. Frontiers in Earth Science (2022).