This file was prepared 20200721 by Gregory C. McLaskey (gcm8@cornell.edu) This file supplements data associated with the publication: "Groove Generation and Coalescence on a Large-Scale Laboratory Fault" AGU Advances - see citation below, Authors: Emily E. Brodsky (brodsky@ucsc.edu), Gregory C. McLaskey (gcm8@cornell.edu), Chun-Yu Ke (ck659@cornell.edu) -------------------------- Dataset Description: These data are from Laboratory Earthquake Experiments from the Cornell 3 m apparatus in support of the following research: Faults are the products of wear processes acting at a range of scales from nanometers to kilometers. Grooves produced by wear are a first-order observable feature of preserved surfaces. However, their interpretation is limited by the complex geological histories of natural faults. Here we explore wear processes on faults by forensically examining a large-scale controlled, laboratory fault which has a maximum offset between the sides of 42 mm and has been reset multiple times for a cumulative slip of approximately 140 mm. We find that on both sides of the fault scratches are formed with lengths that are longer than the maximum offset but less than the cumulative slip. The grooves are explained as a result of interaction with detached gouge rather than as toolmarks produced by an intact protrusion on one side of the fault. The density of grooves increases with normal stress. The experiment has a range of stress of 1-20 MPa and shows a density of 10 grooves/m/MPa in this range. This value is consistent with recent inferences of stress-dependent earthquake fracture energy of 0.2 J/m2 21 /MPa. At normal stresses above 20 MPa, the grooves are likely to coalesce into a corrugated surface that more closely resembles mature faults. Groove density therefore appears to be an attractive target for field studies aiming to determine the distribution of normal stress on faults. At low stresses the groove spacing can be measured and contrasted with areas where high stresses produce a corrugated surface. -------------------------- When utilizing this data, please cite as listed below, and provide reference to one or more of the following associated publications: Dataset: Brodsky, E. E., McLaskey, G. C., Ke, C.-Y. (2020) Data from: Groove Generation and Coalescence on a Large-Scale Laboratory Fault [Dataset]. Cornell University Library eCommons Repository. Publications: Brodsky, E. E., McLaskey, G. C., Ke, C.-Y. (2020) Groove Generation and Coalescence on a Large-Scale Laboratory Fault, AGU Advances, 1, e2020AV000184. https://doi.org/10.1029/2020AV000184 McLaskey, G. C. (2019) Earthquake Initiation from Laboratory Observations and Implications for Foreshocks, Journal of Geophysical Research, https://doi.org/10.1029/2019JB018363 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 -------------------------- This work was enabled by the INSTOC Jack Oliver Visiting Professorship award to EB and we gratefully acknowledge the opportunity. The work was also supported by NSF EAR-1624657 and NSF EAR-1763499. -------------------------- 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. -------------------------- Dataset Description: This dataset consists of the following files: "Brodsky_etal_2020AGU_Dataset.zip" which contains: "moving_block_013019.jpg" - panoramic image of the moving block taken on January 31, 2019 "stationary_block_013019.jpg" - panoramic image of the stationary block taken on January 31, 2019 "stationary_map_01.jpg" through "stationary_map_15.jpg" - the fifteen maps drawn on January 31, 2019 on 8.5 by 11 inch transparencies as originally scanned "Feb2019Profiles.txt" - a tab delimited text file with 6 columns. The first column is the spatial location (in mm) of each data point in each profilometer measurement and columns 2-6 are heights (in microns) of the 5 profilometer measurements shown in Figure 6, from top to bottom, taken on February 1, 2019 during the mapping study. "Feb2019Profile1.xlxs" through "Feb2019Profile5.xlxs" - the orignal files obtained from the Mitutoyo profilometer for the 5 profiles collected in "JFeb 2019 Profiles.txt". These files include details about filtering and other aquisition parameters. "June2020Profiles.txt" - a tab delimited text file with 13 columns. The first column is the spatial location (in mm) of each data point in each profilometer measurement and columns 2-13 are heights (in microns) of the 12 profilometer measurements taken on June 30, 2020 on the large groove shown in Figure 3. Note that only 8 of the 12 measurements are shown in Figure 3. The saved profiles have been filtered. To remove the effects of the filtering, as shown in Figure 3 (c) and (d), the profiles were adjusted to match the unfiltered profiles taken as photographs shown in "June 2020 Unfiltered Profiles.jpg". "June2020UnfilteredProfiles.jpg" - a composite image of photographs of the profiles made prior to filtering. These photographs were used as a guide to remove the filtering. Profiles with filtering removed are shown in Figure 3(c) and (d). "June2020Profile1.xlxs" through "June2020Profile12.xlxs" - the orignal files obtained from the Mitutoyo profilometer for the 12 profiles collected in "June 2020 Profiles.txt". These files include details about filtering and other aquisition parameters. "Brodsky_etal_AGU2020_ExcelArchive.zip" - an archival bundle that contains CSV files and png images transformed from the original .xlsx files. "Brodscky_AGU2020_Readme.txt" - this readme file