To investigate frictional behavior of sediments along the Kumano transect in the Nankai Trough, Japan, friction experiments were conducted using a single-direct shear device at MARUM, University of Bremen under room temperature conditions with 3.5% simulated seawater. Intact sediment cores from the input, prism toe, and inner prism sites collected by the IODP NanTroSEIZE project were tested. In this dataset, parameters of the rate- and state-dependent friction law for each sample were reported, which were obtained by the velocity step tests from 0.01 to 30 μm/sec.

File descriptions: There are 12 parameters:mu0: steady-state friction coefficient before the velocity step (dimensionless)k: stiffness (1/μm)k_std: 1-sigma standard deviation of k (1/μm)a: parameter for direct effect (dimensionless)a_std: 1-sigma standard deviation of a (dimensionless)b: parameter for evolutionary effect (dimensionless)b_std: 1-sigma standard deviation of b (dimensionless)dc: parameter for evolutionary effect (μm)dc_std: 1-sigma standard deviation of dc (μm)a_minus_b: difference between a and b (dimensionless)a_minus_b_std: 1-sigma standard deviation of a_minus_b (dimensionless)R_squared: coefficient of determination (dimensionless)determined for 7 velocity stepping conditions of:velocity before step 0.01 μm/sec to velocity after step 0.03 μm/secvelocity before step 0.03 μm/sec to velocity after step 0.1 μm/secvelocity before step 0.1 μm/sec to velocity after step 0.3 μm/secvelocity before step 0.3 μm/sec to velocity after step 1 μm/sec (no data for C0011B 25R-1)velocity before step 1 μm/sec to velocity after step 3 μm/sec (no data for C0011B 25R-1)velocity before step 3 μm/sec to velocity after step 10 μm/sec (no data for C0011B 25R-1)velocity before step 10 μm/sec to velocity after step 30 μm/sec8 samples along the Kumano transect in the Nankai Trough, Japan, were used:C0011B 25R-1 (IODP Exp. 322, Lat: 32°49.7369′N, Lon: 136°52.9074′E, Depth: 539.79 mbsf)C0011B 8R-3 (IODP Exp. 322, Lat: 32°49.7369′N, Lon: 136°52.9074′E, Depth: 405.57 mbsf)C0006F 19R-1 (IODP Exp. 316, Lat: 33°01.6242′N, Lon: 136°47.6282′E, Depth: 562.67 mbsf)C0006E 36X-1 (IODP Exp. 316, Lat: 33°01.6444′N, Lon: 136°47.6282′E, Depth: 277.54 mbsf)C0011B 55R-5 (IODP Exp. 322, Lat: 32°49.7369′N, Lon: 136°52.9074′E, Depth: 781.80 mbsf)C0006E 12H-3 (IODP Exp. 316, Lat: 33°01.6444′N, Lon: 136°47.6282′E, Depth: 72.80 mbsf)C0002B 63R-1 (IODP Exp. 315, Lat: 33°17.9928′N, Lon: 136°38.2029′E, Depth: 1033.80 mbsf)C0002T 2K-1 (IODP Exp. 358, Lat: 33°18.5070′N, Lon: 136°38.2025′E, Depth: 2840.54 mbsf)We fitted the aging-law type rate- and state-dependent friction law (Dieterich, 1979) to the experimental data using RSFit3000 (Skarbek & Savage, 2019) to obtain these parameters. Experimental data were obtained using the single-direct shear device at MARUM, University of Bremen, Germany.