Violay, M. and Di Toro, G. and Gibert, B. and Nielsen, S. and Spagnuolo, E. and Del Gaudio, P. and Azais, P. and Scarlato, P. G. (2014) 'Effect of glass on the frictional behavior of basalts at seismic slip rates.', Geophysical research letters., 41 (2). pp. 348-355.
We performed 31 friction experiments on glassy basalts (GB) and glass-free basalts (GFB) at slip rates up to 6.5 m s−1 and normal stress up to 40 MPa (seismic conditions). Frictional weakening was associated to bulk frictional melting and lubrication. The weakening distance (Dw) was about 3 times shorter in GB than in GFB, but the steady state friction was systematically higher in GB than in GFB. The shorter Dw in GB may be explained by the thermal softening occurring at the glass transition temperature (Tg ~500°C), which is lower than the bulk melting temperature (Tm ~1250°C) of GFB. Postexperiment microanalyses suggest that the larger crystal fraction measured in GB melts results in the higher steady state friction value compared to the GFB melts. The effect of interstitial glass is to facilitate frictional instability and rupture propagation in GB with respect to GFB.
|Keywords:||Earthquakes, Friction, Basalts, Interstitial glass.|
|Full text:||(VoR) Version of Record|
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|Publisher Web site:||http://dx.doi.org/10.1002/2013GL058601|
|Publisher statement:||Violay, M., G. Di Toro, B. Gibert, S. Nielsen, E. Spagnuolo, P. Del Gaudio, P. Azais, and P. G. Scarlato (2014), Effect of glass on the frictional behavior of basalts at seismic slip rates, Geophysical Research Letters, 41, 348-355, 10.1002/2013GL058601 (DOI). To view the published open abstract, go to http://dx.doi.org and enter the DOI.|
|Date accepted:||27 December 2013|
|Date deposited:||29 September 2015|
|Date of first online publication:||January 2014|
|Date first made open access:||No date available|
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