Document Type

Article

Publication Date

10-9-2016

Publication Title

Geophysical Research Letters

Abstract

The 2014 Mw = 8.1 Iquique (Pisagua), Chile, earthquake sequence ruptured a segment of the Nazca-South America subduction zone that last hosted a great earthquake in 1877. The sequence opened >3700 surface cracks in the fore arc of decameter-scale length and millimeter-to centimeter-scale aperture. We use the strikes of measured cracks, inferred to be perpendicular to coseismically applied tension, to estimate the slip distribution of the main shock and largest aftershock. The slip estimates are compatible with those based on seismic, geodetic, and tsunami data, indicating that geologic observations can also place quantitative constraints on rupture properties. The earthquake sequence ruptured between two asperities inferred from a regional-scale distribution of surface cracks, interpreted to represent a modal or most common rupture scenario for the northern Chile subduction zone. We suggest that past events, including the 1877 earthquake, broke the 2014 Pisagua source area together with adjacent sections in a throughgoing rupture.

Volume

43

Issue

10

First Page

134

Last Page

141

DOI

10.1002/2016GL070284

Rights

An edited version of this paper was published by AGU. Copyright (2016) American Geophysical Union.

To view the published open abstract, go to http://dx.doi.org and enter the DOI.

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