The mechanical data (loads, displacements) recorded during double torsion experiments on samples of 6 shale materials and a sandstone. These experiments were conducted on the I12 beamline, Diamond Light Source, Harwell as part of beamtimes EE13824-1 and EE13824-2 between 26/02/17 and 03/03/17. The data were collected using the standard double-torsion technique, with a load cell behind the actuator recording applied force. The method and results are described in detail by Chandler et al, (2018,submitted) "Correlative optical and X-ray imaging of strain evolution during Double Torsion Fracture Toughness measurements in shale" The data was collected with the aim of correlating local deformation around a progressing fracture (through X-Ray and optical imaging) with recorded mechanical data from the loading system. The data was collected by M. Chandler, A-L Fauchille, J. Mecklenburgh, H. K. Kim and L. Ma, and was processed by M. Chandler and R. Rizzo. The complete dataset is present.

This dataset contains raw mechanical measurements of standard uniaxial tests in 1) tension; 2) compression; 3) compression with creep deformation (load hold); 4) compression with creep and mechanical oscillations. The data is used by Schaefer et al., 2023, (https://doi.org/10.55575/tektonika2023.1.1.10). Experiments consisted of 1) standard Uniaxial Compressive strength tests; 2) Brazilian tensile strength tests; 3) Creep tests in compression and tension; 4) Creep and mechanical oscillations tests in compression and tension. For experiments in 1 in compression, a rock cylinder of 20x40 mm (diameter x height) is loaded at a constant deformation rate in a uniaxial press, for each test type until 1) failure; 3) a target stress that is then held constant for 5h before moving to a different target stress and repeating the process; and 4) to a target stress that is then held for 30 mins before inducing stress oscillations for 40 minutes. The stress is then held constant at the end of oscillations for another 30 mins. Target stresses corresponded to 50; 60 and 70% of the average compressive strength measured in test type 1. For experiments in 1), 3) and 4) in tension, a rock disc of 40x20 mm (diameter x height) is loaded at a constant deformation rate in a uniaxial press under the same stressing configurations as in compression. More details of the methods can be found in the publication Schaefer et al., 2023. Volcanic domes and edifices are inherently unstable owing to their structure and rapid emplacement/growth, further enhanced by both mechanical and thermal variations due to the movement of magma. Understanding the long-term mechanical response and fatigue of their rock constituents is thus key to understanding their stability. Experimental datasets can help quantify the amount of deformation that rocks can sustain before failure, helping us to understand possible rock failure events at larger scale at volcanoes. All data were collected at the University of Liverpool and analysed at the University of Liverpool, UK, at the USGS, USA and LMU Munich, Germany. All samples were collected at Unzen volcano, Japan. Experiments and data analysis were carried in 2021 and 2022.

Collection of data from the PhD Thesis "Thermo-mechanical loading of intact rock and discontinuities" by J Woodman. This collection of data includes raw logged .csv datafiles of uniaxial compression testing and triaxial compression testing on intact synthetic compositions, as well as intact and discontinuous specimens of Thornhill Rock and Midgley Grit at both ambient temperatures, and temperatures up to 100°C.

Unconfined compressive strength data for rocks from TilTil and ElTeniente mines in Chile, plus basic index tests (porosity, density) and Elastic wave velocity for selected samples. Laboratory data collected as part of NERC grant NE/W00383X/1:Geological safety and optimisation in mining operations: towards a new understanding of fracture damage, heterogeneity and anisotropy.

This data has been recorded during a triaxial rock deformation experiment where a Lanhelin granite samples was subjected to controlled shear failure. The data consists of mechanical data (load, displacement, confining pressure, strain gauge data) and acoustic data necessary to reproduce the seismic tomography presented in 'Rupture energetics in crustal rock from laboratory-scale seismic tomography' by Aben, Brantut, Mitchell and David [2019], Geophysical Research Letters. Acoustic data contains AE source locations and arrival times, sensor locations, arrival times of active acoustic surveys.

Geomechanical strength data of mudstone samples collected from the Grey Shale Member, of the Whitby Mudstone Formation of the Lias Group. Testing includes Uniaxial Compressive Strength (UCS), Indirect Tensile Strength (ITS) and Triaxial strength testing completed at the University of Leeds (UoL) and Point Load testing completed at the British Geological Survey (BGS). All sample preparation, preservation and testing were completed to the specification outlined by the ISRM (2007) unless otherwise stated. For all Triaxial testing, each sample was deformed under standard triaxial stress conditions, where the primary principal stress corresponds to the axial stress and the intermediate and minimum principal stresses are equal to that of the confining pressure. The data are separated into individual Excel files (.xlsx), with each file representing a single test. Each file contains time, force, stress, displacement, and strain data.

Geomechanical strength data of mudstone samples collected from the Grey Shale Member of the Whitby Mudstone Formation of the Lias Group. Testing includes cyclic thermo-mechanical loading completed at the British Geological Survey (BGS). All sample preparation, preservation and testing were completed to the specification outlined by the ISRM (ISRM, 1978b; ISRM, 1978a; Bieniawski and Bernede, 1979; ISRM, 1985 for determining the indirect tensile strength, triaxial strength, UCS and point load strength respectively) unless otherwise stated. Each test was comprised of three main stages: 1) A heating stage where the sample is heated to a set temperature loading scheme under pressure conditions of 1-1.4 MPa axial stress and 0.5 MPa confining pressure throughout the heating stage 2) A preloading stage, where the confining pressure is increased to 5 MPa which was held throughout the triaxial compression test. 3) Triaxial compression test, during the active deformation phase, the samples were axially loaded using a constant displacement rate of 0.0012 mm s-1. 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.

Geomechanical strength data of mudstone samples collected from the Gunthorpe Member, of the Sidmouth Mudstone Formation of the Mercia Mudstone Group. The testing was completed at the British Geological Survey (BGS). All sample preparation, preservation and testing were completed to the specification outlined by the ISRM (ISRM, 1978b; ISRM, 1978a; Bieniawski and Bernede, 1979; ISRM, 1985 for determining the indirect tensile strength, triaxial strength, UCS and point load strength respectively) unless otherwise stated. Each test was comprised of three main stages: 1) A heating stage where the sample is heated to a set temperature loading scheme under pressure conditions of 1-1.4 MPa axial stress and 0.5 MPa confining pressure throughout the heating stage 2) A preloading stage, where the confining pressure is increased to 5 MPa which was held throughout the triaxial compression test. 3) Triaxial compression test, during the active deformation phase, the samples were axially loaded using a constant displacement rate of 0.0012 mm s-1. 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. The data are separated into individual Excel files (.xlsx), with each file representing a single test. Each file contains time, force, stress, displacement, and strain data.

The DiGMap Plus dataset is a series of GIS layers describing the engineering properties of materials from the base of pedological soil down to c. 3m depth (ie the uppermost c.2m of geology). These deposits display a variable degree of weathering, but still exhibit core engineering characteristics relating to their lithologies. The 'Strength' dataset covers England, Scotland and Wales and characterises the material lithology, and its strength (for field description purposes) as outlined in documentation relating to BS5930 (1999 and 2003 and Eurocode7).

Datafiles are from a suite of frictional velocity step experiments on clay-bearing fault gouges, at elevated temperatures up to 180°C. The aim was to test if varying temperature reduces the stability of clay-rich faults, measured by the rate and state friction parameter (a-b). Data were collected in the Rock Deformation Laboratory at the University of Liverpool between Oct 2021 to May 2022 by Dr. Isabel Ashman, as part of her NERC EAO DTP studentship. The datafiles are text files of both the raw voltage and calibrated measurements from triaxial deformation experiments. The stability of synthetic kaolinite clay-bearing fault gouges was found to decrease systematically with elevated temperatures commensurate with those found at typical earthquake depths. In materials containing 25-50% clay, the stability of slip decreased with increasing temperature so that the gouges displayed unstable slip at temperatures between 100 and 180°C. At room temperature the same materials showed stable slip and velocity strengthening characteristics. The reduction in stability with increasing temperature coincides with a greater degree of compaction observed in the gouge microstructure and is inferred to result from progressive loss of water adsorbed on the clay surfaces. These results indicate that clay-bearing fault rocks can nucleate unstable slip at conditions common to the clay-bearing brittle crust; a result that adds to the observations of mature clay-bearing faults in nature that can nucleate and propagate earthquakes.