Elastic constants were calculated by using the stress-strain method and density functional theory for crystals of different symmetry. A toolkit was developed to facilitate the input preparation and output processing for elastic calculations using the Vienna Ab Initio Simulation Packge (VASP). The details of the calculation. methods, and the toolkit will be published elsewhere and linked to this deposit. The deposit contains example folders for the monoclinic, orthorhombic, trigonal, tetragonal, hexagonal and cubic lattices. The purpose of this deposit is to provide examples for the toolkit users.

These data contain time series of stress, strain, confining pressure, elastic wave velocities of samples of Vermont antigorite and Westerly granite deformed under hydrostatic and triaxial conditions at room temperature and dry conditions. This dataset is used and fully described/interpreted in the paper: David, E.C., N. Brantut, L.N. Hansen and T.M. Mitchell, Absence of stress-induced anisotropy during brittle deformation in antigorite serpentinite, submitted to J. Geophys. Res.

This dataset contains raw experimental high temperature and acoustic emission testing data on ‘Comiso’ limestone samples as outlined in "Castagna, A., Ougier-Simonin, A., Benson, P. M., Browning, J., Walker, R. J., Fazio, M., & Vinciguerra, S. (2018). Thermal damage and pore pressure effects of the Brittle-Ductile transition in Comiso limestone. Journal of Geophysical Research: Solid Earth, 123(9), 7644-7660.s, http://dx.doi.org/10.1029/2017JB015105". The data is provided in a .zip folder for 2 experiments that are accompanied by a README file for introduction. Files format are Microsoft Excel Worksheet (.xlsx) and data are tabulated. Each file contains the corresponding relevant sample’s details and each column of data is clearly labelled, units included. For each experiment, local time, corrected time, temperature (in degrees Celsius), acoustic emission amplitude (in decibels) and counts were recorded. Cylindrical samples of ‘Comiso’ limestone samples (Ragusa Formation; Sicily) were heat-treated to investigate the effects of thermal stressing on the limestone’s microstructure. In all tests, a controlled heating rate of 1 °C/minute was applied, keeping the specimen at the desired maximum temperature for 30 minutes to allow complete temperature equilibration followed by natural cooling (generally less than<1 °C/minute). The experiments were conducted on the Carbolite CTF12/75/700 tube furnace of the Rock and Ice Physics Laboratory of the University College of London between the 22nd and 28th February, 2016. The experiment were conducted by Drs A. Castagna and J. Browning, both responsible for the collection and interpretation of the data.

This dataset contains raw (clean but not interpreted) triaxial compressive strength data of tests conductive at elevated pressure and temperature as outlined in "Vannucchi, P., Clarke, A., de Montserrat, A., Ougier-Simonin, A., Aldega, L., & Morgan, J. P. (2022). A strength inversion origin for non-volcanic tremor. Nature Communications, 13(1), 2311. https://doi.org/10.1038/s41467-022-29944-8". The data is provided in a .zip folder containing the files of 5 experiments that are accompanied by a README file for introduction. Files format is Microsoft Excel Worksheet (.xlsx) and data are tabulated. Each file contains the corresponding relevant sample’s details, and each column of data is clearly labelled, units included. For each experiment, time, axial force, axial displacement, axial stress, confining displacement, confining pressure, axial strain A and B, axial average strain, circumferential extensometer, circumferential strain, volumetric strain, internal temperature, and axial delta P were recorded. Triaxial testing was undertaken using the MTS 815 servo-controlled stiff frame inside a vessel capable of a confining pressure up to 140 MPa at the Rock Mechanics and Physics Laboratory, British Geological Survey, UK. The confining cell is fitted with external heater bands and utilizing utilizes cascade control from internal and external thermocouples (accurate to ± 0.5°C). An initial axial pre-load of 2.3 kN was applied, to ensure a stable contact and alignment of the platens. The confining pressure vessel was then closed and filled with mineral oil confining fluid. The axial pre-load was maintained whilst the confining pressure was applied at 2 MPa/min to 60 or 120 MPa; these values were chosen to approximately bracket the pressures at the up-dip limit of seismic nucleation, corresponding to 2 – 4 km depth (Arroyo et al., 2014). At this point, whilst held in axial force and confining pressure control, the rig was heated at 2°C/min to 60°C to approximate the average temperature conditions at the depth of the up-dip limit of seismic nucleation (Harris and Spinelli, 2010). The samples were then left for approximately 1 hour allowing thermal equilibrium to be reached throughout the confining fluid and the samples. Once stable, axial loading was initiated in constant axial strain rate control at a rate of 5.0 x 10-6 s-1 until macroscopic failure occurred or a significant amount of post peak-stress axial strain was recorded (between 2% and 5%). We note that one test was conducted at the higher temperature of T=120°C with a result within 2.5% of the strength at T=60°C (Table 1). As this is below the expected sample-to-sample variability, no further temperature studies were conducted. The axial load, axial load actuator displacement, axial stress (s1), differential stress (Q=s1 - s3), confining pressure Pc (= s2= s3), confining pressure actuator displacement, axial strain (eax), circumferential strain (ecirc) and temperature were monitored throughout at sampling frequencies of 1s and 0.5kN. File names are: YYYY-MM-DD_LabProjectNumber_SiteName-SampleNumber

The dataset contains unconfined compressive strength data of salt samples collected from the Northwich Halite Member at the Winsford Mine in Cheshire, UK. Each sample was unconfined and deformed under standard uniaxial stress conditions, where the primary principal stress corresponds to the axial stress and the intermediate and minimum principal stresses are equal to 0. Each sample was axially compressed using either a constant strain rate of 1e-5 per second or a constant loading rate of 200 N/s. The tests were completed using a servo-controlled stiff load frame in the Rock Mechanics and Physics Laboratory at the British Geological Survey, Keyworth UK. The data are separated into individual Microsoft Excel files, with each file representing a single test. Each file contains time, force, stress, displacement, and strain data.