These data files contain the results of Evolved Gas Analysis (EGA) on a Mettler-Toledo TGA-DSC 3+ attached to a Pfeiffer Vacuum GSD 320 gas mass spectrometer on ash samples from the 15 January 2022 eruption of Hunga volcano, Tonga. Samples were heated in Nitrogen at a rate of 5 °C/min from 30 to 150 °C for dehydration purposes and then at a rate of 30 °C/min from 150 °C to 1300 °C. During heating, the relative amount of different volatile species (H2O, CO2, SO2, HCl, and H2S, which are extracted from mass-to-charge ratios of 18, 44, 64, 36, and 34, respectively) were recorded by the gas mass spectrometer. Natural samples collected for the analysis were bulk ash material or correspond to a given ash fraction. Particles were unwashed and dried at 40°C before analysis. We compared the signals for natural samples with (i) a mixture of salt-free dense glassy particles, white and dark pumice (HT10), (ii) pure halite, anhydrite, gypsum, calcite and pyrit, (iii) mix between pure magmatic particles (HT10) from (i) and manually added components from (iii).
This dataset is associated with the publication of Hefny, M., et al. (2020) A laboratory approach for the calibration of seismic data in the western part of the Swiss Molasse Basin: the case history of well Humilly-2 (France) in the Geneva area”. It includes data on mineralogical composition and experimental ultrasonic waves velocity measurements. It contains also seismic parameters calculated for the above-mentioned data. The measurements were performed as part of a database collection (SAPHYR) under the umbrella of the Swiss Commission of Geophysics (SGTK) and a project of the Canton of Geneva (GEothermie 2020), implemented by Services Industriels de Genève (SIG) for geothermal energy development (Moscariello 2019).
Pore pressure reduction in sandstone reservoirs generally leads to small elastic plus inelastic strains. These small strains (0.1 – 1.0% in total) may lead to surface subsidence and induced seismicity. In current geomechanical models, the inelastic component is usually neglected, though its contribution to stress-strain behaviour is poorly constrained.To help bridge this gap, we performed deviatoric and hydrostatic stress-cycling experiments on Slochteren sandstone samples from the seismogenic Groningen gas field in the Netherlands. We explored in-situ conditions of temperature (T = 100°C) and pore fluid chemistry, porosities of 13 to 26% and effective confining pressures (≤ 320 MPa) and differential stresses (≤ 135 MPa) covering and exceeding those relevant to producing fields. The findings of our work are outlined in the corresponding paper. The data presented here are the measured mechanical tabular data and microstructural data (stitched mosaic of backscatter electron images) provided as uncompressed jpg images. In addition, for one sample we include chemical element maps obtained through Electron Dispersive X-ray spectrometry (EDX).