The 2 March 2016 Wharton Basin Mw 7.8 earthquake: High stress drop north‐south strike‐slip rupture in the diffuse oceanic deformation zone between the Indian and Australian Plates

Abstract The diffuse deformation zone between the Indian and Australian plates has hosted numerous major and great earthquakes during the seismological record, including the 11 April 2012 Mw 8.6 event, the largest recorded intraplate earthquake. On 2 March 2016, an Mw 7.8 strike‐slip faulting earthq...

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Main Authors: Thorne Lay, Lingling Ye, Charles J. Ammon, Audrey Dunham, Keith D. Koper
Format: Article
Language:English
Published: Wiley 2016-08-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1002/2016GL069931
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author Thorne Lay
Lingling Ye
Charles J. Ammon
Audrey Dunham
Keith D. Koper
author_facet Thorne Lay
Lingling Ye
Charles J. Ammon
Audrey Dunham
Keith D. Koper
author_sort Thorne Lay
collection DOAJ
description Abstract The diffuse deformation zone between the Indian and Australian plates has hosted numerous major and great earthquakes during the seismological record, including the 11 April 2012 Mw 8.6 event, the largest recorded intraplate earthquake. On 2 March 2016, an Mw 7.8 strike‐slip faulting earthquake occurred in the northwestern Wharton Basin, in a region bracketed by north‐south trending fracture zones with no previously recorded large event nearby. Despite the large magnitude, only minor source finiteness is evident in aftershock locations or resolvable from seismic wave processing including high‐frequency P wave backprojections and Love wave directivity analysis. Our analyses indicate that the event ruptured bilaterally on a north‐south trending fault over a length of up to 70 km, with rupture speed of ≤ 2 km/s, and a total duration of ~35 s. The estimated stress drop, ~20 MPa, is high, comparable to estimates for other large events in this broad intraplate oceanic deformation zone.
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spelling doaj-art-e671e5cf51e94ee9b8bc9c26aa31acf02025-08-20T03:10:28ZengWileyGeophysical Research Letters0094-82761944-80072016-08-0143157937794510.1002/2016GL069931The 2 March 2016 Wharton Basin Mw 7.8 earthquake: High stress drop north‐south strike‐slip rupture in the diffuse oceanic deformation zone between the Indian and Australian PlatesThorne Lay0Lingling Ye1Charles J. Ammon2Audrey Dunham3Keith D. Koper4Department of Earth and Planetary Sciences University of California Santa Cruz California USASeismological Laboratory California Institute of Technology Pasadena California USADepartment of Geosciences Pennsylvania State University University Park Pennsylvania USADepartment of Geosciences Pennsylvania State University University Park Pennsylvania USADepartment of Geology and Geophysics University of Utah Salt Lake City Utah USAAbstract The diffuse deformation zone between the Indian and Australian plates has hosted numerous major and great earthquakes during the seismological record, including the 11 April 2012 Mw 8.6 event, the largest recorded intraplate earthquake. On 2 March 2016, an Mw 7.8 strike‐slip faulting earthquake occurred in the northwestern Wharton Basin, in a region bracketed by north‐south trending fracture zones with no previously recorded large event nearby. Despite the large magnitude, only minor source finiteness is evident in aftershock locations or resolvable from seismic wave processing including high‐frequency P wave backprojections and Love wave directivity analysis. Our analyses indicate that the event ruptured bilaterally on a north‐south trending fault over a length of up to 70 km, with rupture speed of ≤ 2 km/s, and a total duration of ~35 s. The estimated stress drop, ~20 MPa, is high, comparable to estimates for other large events in this broad intraplate oceanic deformation zone.https://doi.org/10.1002/2016GL069931Wharton Basinintraplate deformationstrike‐slip faulting2 March 2016 earthquake
spellingShingle Thorne Lay
Lingling Ye
Charles J. Ammon
Audrey Dunham
Keith D. Koper
The 2 March 2016 Wharton Basin Mw 7.8 earthquake: High stress drop north‐south strike‐slip rupture in the diffuse oceanic deformation zone between the Indian and Australian Plates
Geophysical Research Letters
Wharton Basin
intraplate deformation
strike‐slip faulting
2 March 2016 earthquake
title The 2 March 2016 Wharton Basin Mw 7.8 earthquake: High stress drop north‐south strike‐slip rupture in the diffuse oceanic deformation zone between the Indian and Australian Plates
title_full The 2 March 2016 Wharton Basin Mw 7.8 earthquake: High stress drop north‐south strike‐slip rupture in the diffuse oceanic deformation zone between the Indian and Australian Plates
title_fullStr The 2 March 2016 Wharton Basin Mw 7.8 earthquake: High stress drop north‐south strike‐slip rupture in the diffuse oceanic deformation zone between the Indian and Australian Plates
title_full_unstemmed The 2 March 2016 Wharton Basin Mw 7.8 earthquake: High stress drop north‐south strike‐slip rupture in the diffuse oceanic deformation zone between the Indian and Australian Plates
title_short The 2 March 2016 Wharton Basin Mw 7.8 earthquake: High stress drop north‐south strike‐slip rupture in the diffuse oceanic deformation zone between the Indian and Australian Plates
title_sort 2 march 2016 wharton basin mw 7 8 earthquake high stress drop north south strike slip rupture in the diffuse oceanic deformation zone between the indian and australian plates
topic Wharton Basin
intraplate deformation
strike‐slip faulting
2 March 2016 earthquake
url https://doi.org/10.1002/2016GL069931
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