Journal article

The Fingerprints of Flexure in Slab Seismicity

D Sandiford, LM Moresi, M Sandiford, R Farrington, T Yang

TECTONICS | AMER GEOPHYSICAL UNION | Published : 2020

Abstract

Earthquake moment tensors in eastern Pacific (ePac) slabs typically show downdip tensional (DT) axes, whereas in the western Pacific (wPac), they typically show downdip compressional (DC) axes or have mixed orientations indicative of unbending. Prevailing conceptual models emphasize uniform stress/deformation modes, that is, bulk slab stretching or shortening, as the dominant control on intermediate depth seismic expression. In contrast, we propose that a diversity of seismic expression, including DT- and DC-dominated regions, is consistent with expectations of flexural strain accumulation, based on systemic differences in slab geometry. Our analysis reveals two largely unrecognized features..

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Grants

Awarded by Australian Research Council


Funding Acknowledgements

This work was supported by the Australian Research Council (Discovery grant DP150102887). Development of the Underworld2 code (http://www.underworldcode.org/) was supported by AuScope. DS's postgraduate research at the University of Melbourne was supported by a Baragwanath Geology Research Scholarship. This work was supported by resources provided by The Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia. This work was supported by the Nectar Research Cloud, a collaborative Australian research platform supported by the National Collaborative Research Infrastructure Strategy (NCRIS). The study benefited from discussions and reviews by Greg Houseman, Claire Currie, Norman Sleep, and Laurent Jolivet.