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The Minimum Scale of Grooving on a Recently Ruptured Limestone Fault
Author(s) -
Okamoto K. K.,
Brodsky E. E.,
Thom C. A.,
Smeraglia L.,
Billi A.
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl084889
Subject(s) - geology , scale (ratio) , fault (geology) , seismology , slip (aerodynamics) , brittleness , materials science , physics , composite material , quantum mechanics , thermodynamics
Faults have grooves that are formed by abrasion and wear during slip. Recent observations indicate that this grooving is only a large‐scale feature, indicating brittle behavior has a length scale limit. The connection between this scale and earthquake behavior remains limited because no examples exist from a proven seismogenic fault. Here, we address this problem and analyze differences in this scale between lithologies to further our understanding of the underlying mechanics. This study uses samples from the Mt. Vettoretto fault collected after the Norcia earthquake of 2016. We imaged fault topography with a white light interferometer and 10 μm resolution structure from motion and then calculated a Monte Carlo version of root mean square roughness. We found a minimum scale of grooving of ~100 μm. In comparing this fault to the Corona Heights fault, we find that this minimum grooving scale is consistent with predictions based on material properties.