Seismic Tomography and Mantle Dynamics in Northeast Asia

Seismic tomography has revolutionised our understanding of the mantle beneath Northeast Asia by imaging variations in seismic velocity that record temperature, composition and flow patterns. The subduction of the Pacific plate into the mantle transition zone has created a broad, flat slab whose interaction with overlying mantle produces a “big mantle wedge” characterised by complex anisotropy and flow. High‐resolution tomographic models reveal low‐velocity anomalies beneath intraplate volcanoes such as Changbaishan, indicating hydrous upwellings and partial melt, while high‐velocity zones delineate stagnant, dehydrated slab fragments. Shear wave splitting analyses further constrain asthenospheric flow directions and depth of anisotropy, pointing to both large‐scale corner flow and focused, buoyant plumes rising from the transition zone. These findings link deep processes to surface expressions of volcanism, tectonic subsidence and seismic hazards, and underpin models of mantle convection, slab stagnation and secondary plume formation in a region that exerts a critical influence on East Asian geodynamics.

Research from Nature Portfolio

Recent work has demonstrated that intraplate magmatism in Northeast Asia may be driven by hydrous mantle plumes originating in the transition zone rather than classical thermal anomalies. Careful geochemical analysis of volcanic basalts yields mantle source temperatures within the normal upper‐mantle range, implying that buoyancy arises from water released by a stagnant Pacific slab at 410–660 km depth. Seismological imaging beneath Changbaishan corroborates a vertical, low‐velocity conduit consistent with a water‐rich upwelling. This mechanism explains episodes of dispersed volcanism and large igneous provinces without requiring anomalously hot plumes and highlights the role of slab‐derived fluids in driving mantle dynamics and melt generation.

Seismic Tomography and Mantle Dynamics in Northeast Asia publication trend

The graph below shows the total number of articles in seismic tomography and mantle dynamics in northeast asia across all publications each year (not limited to Nature Index journals).

Technical terms

Seismic tomography: A method that uses travel times of seismic waves to image variations in velocity within Earth’s interior, revealing temperature and compositional heterogeneities.

Big mantle wedge: The region of mantle material lying above a flattened subducted slab, characterised by complex flow and anisotropic fabric.

Shear wave splitting: The phenomenon whereby a shear wave divides into two orthogonally polarised waves upon traversing an anisotropic medium, used to infer mantle flow directions.

Radial anisotropy: A measure of the difference between horizontal and vertical seismic wave speeds, indicative of vertical versus horizontal mineral alignment and flow.

Hydrous plume: A buoyant mantle upwelling enriched in water released from subducted slabs, capable of driving melt generation without requiring excess thermal anomalies.

References

1. Multi-scale anisotropy in NE China: Evidence for localized mantle upwelling. Earth and Planetary Science Letters (2024).
2. Buoyant hydrous mantle plume from the mantle transition zone. Scientific Reports (2019).
3. Evidence for partial melt in the crust beneath Mt. Paektu (Changbaishan), Democratic People’s Republic of Korea and China. Science Advances (2016).
4. Anisotropic Tomography and Dynamics of the Big Mantle Wedge. Geophysical Research Letters (2022).
5. Mantle Melting and Intraplate Volcanism Due to Self‐Buoyant Hydrous Upwellings From the Stagnant Slab That Are Conveyed by Small‐Scale Convection. Geochemistry Geophysics Geosystems (2019).
6. Fingerprinting secondary mantle plumes. Earth and Planetary Science Letters (2022).