Modelling precursory laboratory seismicity using a roughness-based rate- and state-dependent friction model
Type
PreprintAuthors
Selvadurai, Paul Antony
Galvez, Percy

Mai, Paul Martin

Glaser, Steven

Peter, Daniel

Wiemer, Stefan

KAUST Department
Computational Earthquake Seismology (CES) Research GroupEarth Science and Engineering Program
Physical Science and Engineering (PSE) Division
Date
2020-03-27Permanent link to this record
http://hdl.handle.net/10754/662416
Metadata
Show full item recordAbstract
We investigate experimental results from a direct shear friction apparatus, where a fault was formed by pressing mature, worn surfaces of two polymethyl methacrylate (PMMA) samples on top of each other in a dry environment. The fault was sheared until macroscopic stick-slip frictional failure occurred. Before the macro-failure small precursory seismicity nucleated from regions that also experienced aseismic slow slip. These precursory events did not cascade-up into gross fault rupture and arrested locally. Reasons as to why ruptures arrested are investigated using a 1-D rate and state friction (RSF) model. Surface profilometry of the fault surface taken \textit{a posteriori} revealed wear in the form of a bimodal Gaussian distribution of surface height. In our model, this unique distribution of surface roughness is determined to be a proxy for the heterogeneous spatial description of the critical slip distance $D_{c}$. We assume that smooth (polished) sections of fault exhibited lower $D_{c}$ than rougher sections of the bimodal Gaussian roughness profile. We used a quasi-dynamic RSF model that determined localized seismicity initiated at the smooth sections. Source properties: average slip $\delta$, seismic moment $M_{0}$, stress drop $\Delta \tau$ and fracture energy $G^{'}$, were determined for each event. We compare the numerically modeled source properties to experimental source characteristics inferred from seismological estimates using an array of acoustic emission sensors from a concerted study. We discuss similarities, discrepancies and assumptions between these two independent models (kinematic and dynamic) used to study earthquakes for the first time in the laboratory.Citation
Selvadurai, P. A., Galvez, P., Mai, P. M., Glaser, S., Peter, D. B., & Wiemer, S. (2020). Modelling precursory laboratory seismicity using a roughness-based rate- and state-dependent friction model. doi:10.1002/essoar.10502600.1Publisher
WileyAdditional Links
http://www.essoar.org/doi/10.1002/essoar.10502600.1ae974a485f413a2113503eed53cd6c53
10.1002/essoar.10502600.1