Han, C;
Hammond, JOS;
Ballmer, MD;
Wei, W;
Xu, M;
Huang, Z;
Wang, L;
(2024)
Multi-scale anisotropy in NE China: Evidence for localized mantle upwelling.
Earth and Planetary Science Letters
, 625
, Article 118495. 10.1016/j.epsl.2023.118495.
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Abstract
It is commonly proposed that the subduction of the Pacific plate has been responsible for widespread Holocene intraplate volcanism across NE China and the Korean Peninsula. Yet, how this process drives volcanism and even if it plays a critical role remains a topic of vigorous debate. In this study, using seismic data from four networks across NE China and northern Democratic People's Republic of Korea (DPRK), we analyze shear wave splitting in converted P to S-waves at the Moho (Pms), S-waves from the subducted slab interface (local S), and SKS phases. The Pms phases show a relatively weak crustal anisotropy (<0.25 s), with fast polarization directions aligned sub-parallel to major tectonic features. For the local S and SKS phases, fast polarization directions show significant lateral variations. We further perform a quantitative inversion to show that the depth of the anisotropy is ∼150 km, thus driven by flow within the asthenosphere associated with Pacific subduction. However, the presence of many null SKS splitting phases, together with scattered local S anisotropy across a wide range of incidence angles suggests a localized region of vertical flow directly beneath Changbaishan volcano. Such patterns correspond well to regional upper-mantle seismic velocity structure, and suggest that a localized upwelling with a relatively deep origin drives volcanism in the Changbaishan region. Furthermore, we infer that this mantle upwelling is deflected to the SW beneath Changbaishan and spreads asymmetrically at the base of the lithosphere, possibly because of the long history of volcanism in the region.
| Type: | Article |
|---|---|
| Title: | Multi-scale anisotropy in NE China: Evidence for localized mantle upwelling |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.epsl.2023.118495 |
| Publisher version: | https://doi.org/10.1016/j.epsl.2023.118495 |
| Language: | English |
| Additional information: | Copyright © 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
| Keywords: | Intraplate volcanism, Localized upwelling, NE Asia, Asthenospheric flow, Seismic anisotropy |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10183746 |
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