From Slab Coupling to Slab Pull: Stress Segmentation in the Subducting Nazca Plate

W. Bloch, B. Schurr, J. Kummerow, P. Salazar and S. A. Shapiro

2018

Bloch et al., 2018, From Slab Coupling to Slab Pull: Stress Segmentation in the Subducting Nazca Plate, Geophysical Research Letters

eng

Text

@article{doi:10.1029/2018GL078793,
author = {Bloch Wasja and Schurr Bernd and Kummerow Jörn and Salazar Pablo and Shapiro Serge A.},
title = {From Slab Coupling to Slab Pull: Stress Segmentation in the Subducting Nazca Plate},
journal = {Geophysical Research Letters},
volume = {0},
number = {0},
pages = {},
keywords = {seismology, subduction, stress, slab pull, plate coupling},
doi = {10.1029/2018GL078793},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078793},
eprint =
{https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2018GL078793},
abstract = {Abstract We investigate the stress field that the Nazca slab
experiences during subduction beneath the South American plate by
determining the focal mechanisms of moderate subduction‐related
earthquakes continuously from 20‐ to 120‐km depth and inverting for the
stress directions of four slab regions. Our results show the sharp
termination of the coupling zone, which is characterized by compressional
stresses, uplift of the overlying mountain range, and likely the
activation of preexisting slab structures. Beyond and below this zone slab
pull is the dominant stress. Near the slab surface, we also find
signatures of the activation of inherited structures. Deeper in the slab,
fault orientations are more likely controlled by the stress field alone.
Along the subduction pathway, we find indication for an increase of the
absolute slab pull component of the stress field that correlates with an
increase in event rate and the occurrence possibility of M > 7
intermediate depth earthquakes.}
}