TY  - JOUR
AU  - Ryo Okuwaki, Stephen P. Hicks
PY  - 2021//
TI  - Illuminating a Contorted Slab With a Complex Intraslab Rupture Evolution During the 2021 Mw 7.3 East Cape, New Zealand Earthquake
KW  - earthquake rupture finite-fault inversion Hikurangi intraslab earthquakes slab geometry source imaging
N2  - 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.
SN  - 1944-8007
UR  - http://dx.doi.org/10.1029/2021GL095117
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=8313), last updated on Mon, 01 Jul 2024 12:55:42 +0200
ID  - RyoOkuwaki2021
ER  -