Nanometric flow and earthquake instability
Name
s41467-021-26996-0.pdf
Description
Published version
Size
2.3 MB
Format
Unknown
Checksum (MD5)
d521c80448626b94c38f7c358242a22f
Author(s)
Sun, Hongyu
Pec, Matej
Date Issued
December 2021
Journal
Nature Communications
Publisher
Springer Science and Business Media LLC
Citation
Sun, Hongyu and Pec, Matej. 2021. "Nanometric flow and earthquake instability." Nature Communications, 12 (1).
Version
Final published version
Abstract
Fault zones accommodate relative motion between tectonic blocks and control earthquake nucleation. Nanocrystalline fault rocks are ubiquitous in “principal slip zones” indicating that these materials are determining fault stability. However, the rheology of nanocrystalline fault rocks remains poorly constrained. Here, we show that such fault rocks are an order of magnitude weaker than their microcrystalline counterparts when deformed at identical experimental conditions. Weakening of the fault rocks is hence intrinsic, it occurs once nanocrystalline layers form. However, it is difficult to produce “rate weakening” behavior due to the low measured stress exponent, n, of 1.3 ± 0.4 and the low activation energy, Q, of 16,000 ± 14,000 J/mol implying that the material will be strongly “rate strengthening” with a weak temperature sensitivity. Failure of the fault zone nevertheless occurs once these weak layers coalesce in a kinematically favored network. This type of instability is distinct from the frictional instability used to describe crustal earthquakes.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1038/s41467-021-26996-0
