Okuwaki, R, Hicks, SP, Craig, TJ orcid.org/0000-0003-2198-9172 et al. (4 more authors) (2021) Illuminating a Contorted Slab with a Complex Intraslab Rupture Evolution during the 2021 Mw 7.3 East Cape, New Zealand Earthquake. Geophysical Research Letters. ISSN 0094-8276
Abstract
The state-of-stress within subducting oceanic plates controls rupture processes of deep intraslab earthquakes. However, little is known about how the large-scale plate geometry and the stress regime relate to the physical nature of the deep-intraslab earthquakes. Here we find, by using globally and locally observed seismic records, that the moment magnitude 7.3 2021 East Cape, New Zealand earthquake was driven by a combination of shallow trench-normal extension and unexpectedly, deep trench-parallel compression. We find multiple rupture episodes comprising a mixture of reverse, strike-slip, and normal faulting. Reverse faulting due to the trench-parallel compression is unexpected given the apparent subduction direction, so we require a differential-buoyancy driven stress rotation which contorts the slab near the edge of the Hikurangi plateau. Our finding highlights that buoyant features in subducting plates may cause diverse rupture behavior of intraslab earthquakes due to the resulting heterogeneous stress state within slabs.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Funding Information: | Funder Grant number Royal Society URF\R1\180088 Royal Society RGF\EA\181084 |
Depositing User: | Symplectic Publications |
Date Deposited: | 15 Dec 2021 12:25 |
Last Modified: | 15 Dec 2021 12:26 |
Status: | Published online |
Publisher: | Wiley |
Identification Number: | 10.1029/2021gl095117 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:181573 |