Raw mechanical data from currently unpublished sintering experiments using glass beads in a triaxial pressure vessel as well as porosity, permeability results of sintering under constant (uniaxial) load. These experiments will be submitted for publication in the future. All data were collected from 2021 onwards and analysed at LMU Munich. Synthetic glass bead samples are sintered to a target porosity in a furnace to make uniform (homogeneous) porous glass samples, before being cooled, measured for porosity and permeability and then placed in a furnace either: 1) in a uniaxial press; or 2) a triaxial pressure vessel. In 1) a constant load is applied for 3 or 5h; In 2) a hydrostatic or deviatoric stress is applied for variable amount of time while the permeability evolution is constantly measured. These experiments impart physical changes to the porous samples. All samples porosity and permeability (using constant flow rate and nitrogen as a permeating fluid) are also measured post-experiment. Sintered glass beads act as an analogue for magmas. Understanding the evolution of transient porous network in magmas is key to understanding pore pressure evolution in volcanic conduits, which controls effusive-explosive transitions

These are data pertaining to Wadsworth et al. (2022) which are published here: https://doi.org/10.1016/j.jvolgeores.2022.107672. How: Samples were set in epoxy and ground to the point where half of the glass chips collected were ground away. Then the sample was turned around and the other half of the particles were ground away until a thin slice of the chips remained at about 0.05 mm thick. At this point, the thin slices of volcanic chips were measured using Fourier Transform Infrared How: Spectroscopy (FTIR) at JAMSEC (Japan) by Iona McIntosh in collaboration with coauthors and Fabian Wadsworth. The data are the primary data in this manuscript. These data were collected to investigate how much water is remnant in particles that are known to have formed by the competition between degassing of H2O and sintering in volcanoes. That competition has implications for the development and destruction of permeability, which is at the core of this project.

This dataset contains experimental data supporting Vasseur et al. (2023) https://doi.org/10.1111/jace.19120, which investigates the process of glass sintering during dehydration. The experiments were conducted in 2022 at LMU (Munich, Germany) . The samples were synthetic and so were not collected at any given site but were created in the laboratory. For each experiment presented, a sample of glass powder was hydrated by exposing it to a hydrous (H2O) atmosphere at high temperature (600-700 C) for a number of hours. The glass particles were then hydrated, and this fact was checked by looking for a relative mass loss if the same powder was returned to high temperature but under a non-hydrous atmosphere; indeed, mass loss occurred as the water left the particles again. That mass loss was measured and the kinetics of mass loss were analysed. The data demonstrate that there is a quantifiable competition between the rate at which water will move into or out of particles and the rate at which particles will sinter together. This same competition is relevant to volcanic eruptions and has knock-on implications for the evolution of permeability of magmas, which is a prominent area of study for this grant. These data were collected by F. Wadsworth, analysed by J. Vasseur, and the paper was both facilitated by and written by Y. Lavallée and D. B. Dingwell. All authors were responsible for the output of the data.

These are so-called relaxation datasets for the rate of structural relaxation of glass exposed to high temperatures. The glass is in the form of chips collected during the IDDP-1 drilling project at Krafla Iceland (more below). The chips were generated during drilling in 2011. However, the analysis presented here was developed in 2023 ahead of the ultimate publication in 2024. The data were collected using differential scanning calorimetry, which is a standard method in glass science for measuring the enthalpy of glass relaxation as it is returned to the high temperatures from which it formed. The relaxation rate of the glass from IDDP-1 tells us directly what the rate was at which it cooled. That "cooling rate" in turn allows us to understand what the time available for fragmentation and sintering in geothermal systems is, which has informed this wider project.