This file was prepared 20191029 by Chun-Yu Ke (ck659@cornell.edu) This file supplements data associated with the publication: "Rupture Termination in Laboratory-Generated Earthquakes" Geophysical Research Letters Authors: Chun-Yu Ke (ck659@cornell.edu), Gregory C. McLaskey (gcm8@cornell.edu) and David S. Kammer (dkammer@ethz.ch) Alternate contact: Bill S. Wu (sw842@cornell.edu) -------------------------- Dataset Description: These data are from Laboratory Earthquake Experiments from the Cornell 3 m apparatus in support of the following research: Loading a 3-meter granite slab containing a saw-cut simulated fault, we generated rupture events that spontaneously nucleate, propagate, and arrest before reaching the ends of the sample. These rupture events have a slip distribution that varies along the fault and make them more similar to natural earthquakes than standard stick-slip events that rupture the entire sample. Through LEFM (Linear Elastic Fracture Mechanics), we showed how the balance between energy release rate and fracture energy governs the termination of a rupture. In our experiments, fracture energy is essentially constant compared to the orders-of-magnitude variations in energy release rate so ruptures terminate because they run out of available strain energy. The utility of the model for both 3-m rock experiments and 200-mm PMMA experiments, and the similarity of fracture energy coefficient between the two materials, verifies the adequacy of PMMA as an analog to crustal rock in this context. Finally, the LEFM-based model provides a framework for linking friction properties and on-fault stress conditions to observable earthquake sequences. -------------------------- When utilizing this data, please cite as listed below, and provide reference to one or more of the following associated publications: Dataset: Ke, C.-Y., McLaskey, G. C., Kammer, D. S. (2018) Data from: Rupture Termination in Laboratory-Generated Earthquakes [dataset], Cornell University eCommons Repository. https://doi.org/10.7298/71h5-6624 Publications: Ke, C.-Y., McLaskey, G. C., Kammer, D. S. (2018) Rupture Termination in Laboratory-Generated Earthquakes. Geophysical Research Letters 45(23):12784-12792. https://doi.org/10.1029/2018GL080492 Wu, B. S., and McLaskey, G. C. (2019) Contained Laboratory Earthquakes Ranging from Slow to Fast, Journal of Geophysical Research: Solid Earth, 124(10):20170-10291. https://doi.org/10.1029/2019JB017865 -------------------------- This work was sponsored by USGS Earthquake hazards grant G18AP00010 and National Science Foundation grants EAR-1645163, EAR-1763499, and EAR-1847139 -------------------------- These data are shared under a Creative Commons Universal Public Domain Dedication (CC0 1.0); the data will be openly available for re-use, modification and distribution; proper attribution to the original data creators is expected. See citation information above. -------------------------- File labelling: Experiments were conducted in runs which consist of series of events. We refer to the run generated after a large increase in normal stress as a Poisson expansion sequence, denoted “P” for “Poisson”. For catalog purposes a run called “FS01-20-10MPa-P-3” denotes the third Poisson expansion sequence at ~10 MPa normal stress in the 20th overall day of experiments on the first set of blocks used on the Cornell 3 m apparatus. Individual slip events are labeled by their number since the beginning of the slip sensor data file, where their timing are stored in ‘event_time’ described below. Experiment data: Each .mat file contains an array labeld ‘event_time’ and three MATLAB structures: ‘pressure’, ‘slip’, and ‘strain’, described below. ‘pressure’ contains a MATLAB structure with 2 fields: ‘time’ and ‘signal’. ‘pressure.time’ is a column vector describing the time stamp (seconds) of each row of data found in ‘signal’. All data were recorded at 50 kHz and then averaged down to 5 kHz, which is provided here. ‘pressure.signal’ is a 2-column matrix, storing data recorded from hydraulic pressure sensors in the array of normal loading cylinders (column 1) and shear loading cylinders (column 2). Data is in Volts where 5 V is 10,000 psi. The conversion from Voltage to sample average stress is 6.4 MPa/V for the normal stress (East-side cylinders) and 3.2 MPa/V for the shear stress (North-side cylinders). ‘slip’ contains a MATLAB structure with 2 fields: ‘time’ and ‘signal’. ‘slip.time’ is a column vector describing the time stamp (seconds) of each data point found in ‘signal’. All data were recorded at 50 kHz and then averaged down to 5 kHz, which is provided here. ‘slip.signal’ is a 16-column matrix, storing data recorded from eddy current sensor channels E1 - E16, respectively. E1 is near the forcing end (North) and E16 is near the leading edge (South) of the sample. All data is in units of Volts and the conversion factor is 128 microns/V. ‘strain’ contains a MATLAB structure with 2 fields: ‘time’ and ‘signal’. ‘strain.time’ is a column vector describing the time stamp (seconds) of each data point found in ‘signal’. Data were recorded at 100 Hz for FS01-013 to FS01-017, 150 Hz for FS01-018 to FS01-020. ‘strain.signal’ is a 24-column matrix, storing data recorded from strain gauge rosette channels S1a, S1b, S1c, S2a, S2b, S2c, ..., S8a, S8b, S8c, respectively. S1 is near the forcing end (North) and S8 is near the leading edge (South) of the sample. SIa, SIb, and SIc are oriented at 45, 90, and 135 degrees from the fault for I = 1 - 8. All data are zeroed at the beginning of each experiment, where normal and shear loading were held at a negligible level since the end of the previous experiment. All data is in units of strain (unitless). ‘event_time’ is a column vector describing the time stamp (seconds) of each identified rupture event. Note: pressure and slip data were recorded on a single, 20-channel digitizer (Elsys 2) and the time stamps for those data are identical. Strain was recorded simultaneously with a different digitizer. The locations of the slip and strain sensors are provided below. Sensor X (m) Y (m) Z (m) Sensor X (m) Y (m) Z (m) E1 0.050 0.000 0.000 S1 0.250 0.007 0.000 E2 0.250 0.000 0.000 S2 0.650 0.007 0.000 E3 0.450 0.000 0.000 S3 1.050 0.007 0.000 E4 0.650 0.000 0.000 S4 1.450 0.007 0.000 E5 0.850 0.000 0.000 S5 1.850 0.007 0.000 E6 1.050 0.000 0.000 S6 2.250 0.007 0.000 E7 1.250 0.000 0.000 S7 2.650 0.007 0.000 E8 1.450 0.000 0.000 S8 3.050 0.007 0.000 E9 1.650 0.000 0.000 E10 1.850 0.000 0.000 E11 2.050 0.000 0.000 E12 2.250 0.000 0.000 E13 2.450 0.000 0.000 E14 2.650 0.000 0.000 E15 2.850 0.000 0.000 E16 3.050 0.000 0.000