DOI: 10.5061/dryad.s4mw6m9gn
title: Fault asperities and the transition from aseismic creep to stick-slip: implications for earthquake precursors

description: Fault asperities significantly influence fault friction and stability,
 stress patterns and the nature of slip events. Response is contrasted for
 stress-reactivated laboratory faults both with and without asperities.
 Asperities contribute to fault strength, necessitating a longer distance
 for slip nucleation, and elevating the energetics of slip. Asperities
 result in a heterogeneous distribution of fault rupture manifest as slip
 pulses and variable-speed slip as aligned with the cascade failure model
 for earthquakes. These asperities on the fault surface act as both
 barriers and stress concentrators, influencing the initiation and
 progression of seismic events. Our findings suggest that the pre-seismic
 time window, modulated by an asperity, can serve as a critical indicator
 for fault slip forecasting. These insights into the mechanical behavior of
 asperities under different stress regimes enhance our understanding of
 fault slip dynamics, towards improving earthquake prediction and assessing
 seismic hazard.
description: # Fault asperities and the transition from aseismic creep to stick-slip:
 implications for earthquake dynamics
 [https://doi.org/10.5061/dryad.s4mw6m9gn](https://doi.org/10.5061/dryad.s4mw6m9gn) ## Description of the data and file structure **Data of Fault Asperities Slip Experiments: Open Source Data** This repository contains the data and file structure related to the research article titled "Fault Asperities and the Transition from Aseismic Creep to Stick-Slip: Implications for Earthquake Precursors" by Chongyuan Zhang, Dongjue Fan, Derek Elsworth, Manchao He, and Hao Zhang. The data provides insights into the behavior of fault asperities and their influence on seismic activity. **Data Acquisition Method** The data was obtained using a stiff GCTS (Giga-Cycle Torsion Shear) compression frame with a stiffness of 10.5 MN/mm. The reactivation experiments were conducted within a pressurized coreholder on both smooth faults and those with asperities. The experiments were performed at four different confining stresses: 5, 10, 15, and 30 MPa, to examine the impact of normal stress on fault slip behavior. The samples were first subjected to a predetermined confining pressure, and then reactivation was conducted under axial stress control at a rate of 0.001 MPa/s. This controlled experimental setup allowed for the precise measurement of fault slip behavior under varying conditions of normal stress. The dataset includes several Excel files (.xlsx) that detail experimental results under different confining pressures. Each file is named according to the confining pressure and whether the fault model includes asperities. The files are as follows: ## Files and Variables **Smooth Fault Data Files:** Smooth_Fault_5MPa.xlsx: Data for Experiment 1-1 with a confining pressure of 5MPa. Smooth_Fault_10MPa.xlsx: Data for Experiment 1-1 with a confining pressure of 10MPa. Smooth_Fault_15MPa.xlsx: Data for Experiment 1-1 with a confining pressure of 15MPa. Smooth_Fault_30MPa.xlsx: Data for Experiment 1-1 with a confining pressure of 30MPa. **Fault with Asperity Data Files:** Fault_with_asperity_5MPa.xlsx: Data for Experiment 1-1 with a confining pressure of 5MPa. Fault_with_asperity_10MPa.xlsx: Data for Experiment 1-1 with a confining pressure of 10MPa. Fault_with_asperity_15MPa.xlsx: Data for Experiment 1-1 with a confining pressure of 15MPa. Fault_with_asperity_30MPa.xlsx: Data for Experiment 1-1 with a confining pressure of 30MPa. #### Smooth Fault Variables **Description:**  * Time:Time in seconds since the start of the experiment. * Sd - Deviator Stress:The difference between the maximum and minimum principal stresses. * Confining Pressure: The uniform pressure applied to the sides of the sample. * Axial Displacement 1:The displacement measured along the axis of the sample at position 1. * Axial Displacement 2:The displacement measured along the axis of the sample at position 2. * Circum. Displacement:The displacement measured around the circumference of the sample. #### Fault with Asperity Variables **Description:**  * Time:Time in seconds since the start of the experiment. * Stress:The stress applied along the axis of the sample. * Shear stress:The stress causing deformation by shear. * Normal stress:The stress acting perpendicular to the surface of the fault. * Axial Dispalcement:The displacement measured along the axis of the sample. * Shear Displacement:The displacement measured in the direction of the shear stress. ## Code/software To view the data provided in this repository, you can use Microsoft Excel, a widely available spreadsheet program that can open, view, and manipulate the Excel files (`.xlsx`) contained in this dataset. No additional software or special permissions are required to view the raw data files. ## Access information Other publicly accessible locations of the data: * The dataset provided in this repository is exclusively available through this source. There are no additional publicly accessible locations for the data. The data is intended for research and educational purposes, and we encourage users to cite the original research article when utilizing this dataset. Data was derived from the following sources: * The raw data was collected through laboratory experiments conducted using a stiff GCTS compression frame and pressurized coreholder, as described in the Data Acquisition Method section.