S‐to‐P Receiver Function Imaging of Lithospheric Discontinuities in New Zealand at the Hikurangi Subduction Zone
Abstract Subduction zones are important regions for understanding plate tectonic processes. New Zealand experiences slow slip, volcanism, and back‐arc rifting, and has evidence of large megathrust events and tsunamis. We use S‐to‐P receiver functions to image lithospheric discontinuities beneath the...
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Wiley
2025-03-01
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| Series: | Geochemistry, Geophysics, Geosystems |
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| Online Access: | https://doi.org/10.1029/2024GC011897 |
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| author | William A. Buffett Catherine A. Rychert Nicholas Harmon |
| author_facet | William A. Buffett Catherine A. Rychert Nicholas Harmon |
| author_sort | William A. Buffett |
| collection | DOAJ |
| description | Abstract Subduction zones are important regions for understanding plate tectonic processes. New Zealand experiences slow slip, volcanism, and back‐arc rifting, and has evidence of large megathrust events and tsunamis. We use S‐to‐P receiver functions to image lithospheric discontinuities beneath the North Island of New Zealand. A positive discontinuity interpreted as the Moho is imaged at 15–30 ± 3 km depth beneath the overriding Australian Plate. In some locations, near the interface of the Pacific and Australian Plates, we don't image the Pacific Plate Moho, and the Australian Plate Moho is faint or absent. The former could be related to the increasing dip or eclogitization of the Pacific Plate crust, and the latter is likely related to mantle wedge serpentinization. A negative velocity discontinuity associated with the lithosphere‐asthenosphere boundary (LAB) of the Australian Plate is imaged at 63–80 ± 8 km depth across the northwestern side of the island. Negative discontinuities are imaged beneath the southern Pacific Plate at 85–105 ± 10 km and 130 ± 13 km depth, representing either a mid‐lithospheric discontinuity (MLD) and a deeper LAB, or more likely a shallow LAB and a deeper artifact, given that the latter is better aligned with previous work. Beneath the Australian Plate, asthenospheric melt is inferred in the northwest beneath several regions of active volcanism. Beneath the Pacific Plate, asthenospheric melt is inferred near the trench, also corresponding to the transition to where the plates become locked; therefore, plate locking could be related to the buoyancy of the melt. |
| format | Article |
| id | doaj-art-2651c458aa4e435e87b3623dda2a7bd8 |
| institution | DOAJ |
| issn | 1525-2027 |
| language | English |
| publishDate | 2025-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj-art-2651c458aa4e435e87b3623dda2a7bd82025-08-20T02:48:23ZengWileyGeochemistry, Geophysics, Geosystems1525-20272025-03-01263n/an/a10.1029/2024GC011897S‐to‐P Receiver Function Imaging of Lithospheric Discontinuities in New Zealand at the Hikurangi Subduction ZoneWilliam A. Buffett0Catherine A. Rychert1Nicholas Harmon2Ocean and Earth Sciences University of Southampton Southampton Hants UKOcean and Earth Sciences University of Southampton Southampton Hants UKOcean and Earth Sciences University of Southampton Southampton Hants UKAbstract Subduction zones are important regions for understanding plate tectonic processes. New Zealand experiences slow slip, volcanism, and back‐arc rifting, and has evidence of large megathrust events and tsunamis. We use S‐to‐P receiver functions to image lithospheric discontinuities beneath the North Island of New Zealand. A positive discontinuity interpreted as the Moho is imaged at 15–30 ± 3 km depth beneath the overriding Australian Plate. In some locations, near the interface of the Pacific and Australian Plates, we don't image the Pacific Plate Moho, and the Australian Plate Moho is faint or absent. The former could be related to the increasing dip or eclogitization of the Pacific Plate crust, and the latter is likely related to mantle wedge serpentinization. A negative velocity discontinuity associated with the lithosphere‐asthenosphere boundary (LAB) of the Australian Plate is imaged at 63–80 ± 8 km depth across the northwestern side of the island. Negative discontinuities are imaged beneath the southern Pacific Plate at 85–105 ± 10 km and 130 ± 13 km depth, representing either a mid‐lithospheric discontinuity (MLD) and a deeper LAB, or more likely a shallow LAB and a deeper artifact, given that the latter is better aligned with previous work. Beneath the Australian Plate, asthenospheric melt is inferred in the northwest beneath several regions of active volcanism. Beneath the Pacific Plate, asthenospheric melt is inferred near the trench, also corresponding to the transition to where the plates become locked; therefore, plate locking could be related to the buoyancy of the melt.https://doi.org/10.1029/2024GC011897New Zealandreceiver functionS‐to‐Psubduction zonelithosphere‐asthenosphere boundaryMoho |
| spellingShingle | William A. Buffett Catherine A. Rychert Nicholas Harmon S‐to‐P Receiver Function Imaging of Lithospheric Discontinuities in New Zealand at the Hikurangi Subduction Zone Geochemistry, Geophysics, Geosystems New Zealand receiver function S‐to‐P subduction zone lithosphere‐asthenosphere boundary Moho |
| title | S‐to‐P Receiver Function Imaging of Lithospheric Discontinuities in New Zealand at the Hikurangi Subduction Zone |
| title_full | S‐to‐P Receiver Function Imaging of Lithospheric Discontinuities in New Zealand at the Hikurangi Subduction Zone |
| title_fullStr | S‐to‐P Receiver Function Imaging of Lithospheric Discontinuities in New Zealand at the Hikurangi Subduction Zone |
| title_full_unstemmed | S‐to‐P Receiver Function Imaging of Lithospheric Discontinuities in New Zealand at the Hikurangi Subduction Zone |
| title_short | S‐to‐P Receiver Function Imaging of Lithospheric Discontinuities in New Zealand at the Hikurangi Subduction Zone |
| title_sort | s to p receiver function imaging of lithospheric discontinuities in new zealand at the hikurangi subduction zone |
| topic | New Zealand receiver function S‐to‐P subduction zone lithosphere‐asthenosphere boundary Moho |
| url | https://doi.org/10.1029/2024GC011897 |
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