Quantifying dynamic pressure and temperature conditions on fault asperities during earthquake slip - supporting data

New insights into the pressure and temperature conditions on fault surfaces during seismic slip are provided by Raman-active vibrational modes of SiO2 glass. Here we provide the data collected relating to experiments performed on triaxial apparatus at room temperature and high normal stresses on pre-ground, high-purity silica glass surfaces. During slip, velocities exceed 0.32 m s-1 over durations of less than one millisecond, generating frictional heat and locally melting the fault surfaces. Temperature increases permit structural rearrangement within the melt; these changes are preserved by rapid quenching. Using Raman spectroscopy, we analyse melt-welded regions and show that these areas exhibit systematic changes in the spectra of silica. Changes result from a decrease in the inter-tetrahedral Si-O-Si bond angle and are correlated to increasing silica glass density in the slip regions. Densification results from both rapid cooling rates and exposure to very high pressures at asperity contacts. We use data from other experiments to calibrate these effects, estimating quench temperatures up to 1800 K and pressures of ~180 MPa. These results provide the first quantitative evidence for the effects of quench rates and high inter-asperity pressures on the physics of melting and quenching during seismic slip and its impact on fault behaviour.
Type
collection
Title
Quantifying dynamic pressure and temperature conditions on fault asperities during earthquake slip - supporting data
Brief Title
Dynamic pressure on fault asperities during lab earthquakes
Collection Type
Dataset
Access Privileges
Research School of Earth Sciences
DOI - Digital Object Identifier
10.25911/5f7fbf66a478b
Metadata Language
English
Data Language
English
Significance Statement
First experimental results showing that the structure of SiO2 glass changes at conditions equivalent to fault surfaces during an earthquake.
Brief Description
Data from an experimental study looking at structural changes in SiO2 glass at high pressures, temperatures and sliding velocities. Results have implications for asperity behaviour during earthquakes.
Full Description
New insights into the pressure and temperature conditions on fault surfaces during seismic slip are provided by Raman-active vibrational modes of SiO2 glass. Here we provide the data collected relating to experiments performed on triaxial apparatus at room temperature and high normal stresses on pre-ground, high-purity silica glass surfaces. During slip, velocities exceed 0.32 m s-1 over durations of less than one millisecond, generating frictional heat and locally melting the fault surfaces. Temperature increases permit structural rearrangement within the melt; these changes are preserved by rapid quenching. Using Raman spectroscopy, we analyse melt-welded regions and show that these areas exhibit systematic changes in the spectra of silica. Changes result from a decrease in the inter-tetrahedral Si-O-Si bond angle and are correlated to increasing silica glass density in the slip regions. Densification results from both rapid cooling rates and exposure to very high pressures at asperity contacts. We use data from other experiments to calibrate these effects, estimating quench temperatures up to 1800 K and pressures of ~180 MPa. These results provide the first quantitative evidence for the effects of quench rates and high inter-asperity pressures on the physics of melting and quenching during seismic slip and its impact on fault behaviour.
Contact Email
kathryn.hayward@anu.edu.au
Contact Address
Research School of Earth Sciences 142 Mills Road Canberra ACT 2601
Principal Investigator
Kathryn S Hayward
Supervisors
Stephen S Cox
Collaborators
Charles Le Losq
Fields of Research
030606 - Structural Chemistry and Spectroscopy; 040312 - Structural Geology
Type of Research Activity
Pure basic research
Date of data creation
2018
Year of data publication
2020
Publisher for Citation
The Australian National University Data Commons
Access Rights Type
Open
Rights held in and over the data
CC BY
Licence Type
CC-BY - Attribution
Retention Period
Indefinitely
Data Size
9.41 MB
Data Management Plan
No
Status: Published
Published to:
  • Australian National University
  • Australian National Data Service
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