Data and code accompanying a paper entitled "Pervasive Velocity-Weakening Behavior of Simulated Quartz Gouge at Crustal Faulting Conditions"
Description
The dataset contains the processed data from 29 experiments, where were performed, using the ring-shear hydrothermal deformation apparatus, on simulated quartz gouges at a fixed effective normal stress of 50 MPa and a fluid pressure of 100 MPa, exploring the friction parameters over a wide range of temperatures (25-650 °C) and velocities characteristic of earthquake nucleation and subsequent subseismic acceleration (1 nm/s-300 μm/s) with small steps (1.75-3 folds). The information of all the 29 experiments is given in table named "Summary of experiments". In the individual experiment, the 'text' file entitled "Data_uxxx" (where xxx is the experiment number) is a table, including the following 15 columns: Time Normalload Pf T Displ LPv TauAB Taucorr Mu Mucorr h hlvdt Ec Vsam Vload with the following 15 units: s MPa MPa degreeC mm micron/s MPa MPa -- -- micron micron micron micron/s micron/s The MATLAB code (Code.rar) can interactively process velocity-step datasets. The tool includes automated segmentation of individual velocity steps, extraction of the direct effect for stable sliding, and determination of (a-b) values for both stable and unstable bahaviors using the average-friction method. For unstable behaviors (e.g., stick slips), the code incorporates the RSF fitting approach, using the average-friction results as initial guesses to enhance the efficiency and robustness of the optimization. Ring_CalOverview.m: segmentation of individual velocity steps; Ring_RSF_e.m: quantify the direct effect during stable sliding, and determines (a − b) values for both stable and unstable behaviors using the average-friction method. For unstable events (e.g., stick-slip), the code integrates RSF fitting, using average-friction results as initial parameter guesses to enhance the efficiency and robustness of the optimization. RSF combine_plot1.m and RSF combine_plot2.m: compile and present results from different experiments. Other files are called by the above.