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 datasets are for samples collected from Volcan de Colima (Mexico) which is at coordinates: 19°30’46" N 103°37’02" W / 19.512727°N 103.617241°W. This volcano erupts magmas that are crystal-bearing, making those cooled volcanic rocks ideal for experimentation. And so samples were cored from blocks from that volcano and those cores were then returned to high temperatures (up to 1000 C) and then deformed under controlled stresses. These data form the central part of this publication: https://doi.org/10.1016/j.jvolgeores.2024.108198. The deformation experiments were performed at LMU (Munich, Germany). The volcano coordinates from which the samples were collected are given above. The samples were deformed in a high temperature hydraulic press equipped with acoustic emission sensors. This is the ideal device for determining the behaviour of the magmas from Volcan de Colima under the same stresses and temperatures at which they were erupted. The data give key clues as to the modes of flow behaviour of the magma in volcanoes. This work provides generalised insights into magma flow behaviour.

This dataset contains petrophysical characteristics of andesite samples (geometry, porosity, permeability) before and after a series of mechanical tests (which were conducted as part of another project). The data is presented in the publication Lamur et al., 2023 (https://doi.org/10.1038/s41598-022-26721-x). The data were collected at the University of Liverpool, analysed at the University of Liverpool and LMU Munich. All samples were collected on Colima volcano, Mexico. Experiments were conducted in 2021 and data analysed throughout 2021 and 2022. For each experiment, a rock cylinder of 25x50 mm (diameter x height) is prepared. Porosity data is calculated from sample geometry and volume measured in a helium pycnometer. Permeameter data is output automatically from the permeameter when a constant flow rate of helium gas through the sample is achieved, at which point the pressure differential and flow rate are used to calculate permeability. The values are for andesite samples from Colima volcano, pre- and post- mechanical testing. The data show the extent of changes of petrophysical properties possible by mechanical deformation in the brittle regime. Volcanic environments are often subjected to low magnitude; repetitive earthquakes that may contribute to the overall rock mass (or volcanic edifice/dome) fatigue. Understanding how such mechanical oscillations may change the characteristics of the volcanic rocks comprising the edifice can help better understanding associated hazards.

These data contain 1) load string compliance mechanical data used to retrieve the absolute sample deformation (Compliance folder); 2) Acoustic emissions data (RawData_AEs folder); 3) Compaction data of the granular packs (RawData_Press folder). These data we used for the publication by Zorn et al., 2024 (https://doi.org/10.30909/vol.07.02.765783). A PDF document detailing further information of the contents of each folder entitled "Zorn_Compaction_Data_Overview" is provided. All data were collected and analysed at LMU Munich on samples from the Eifel Volcanic Field (Germany) and from the Krafla caldera (Iceland). The geographical location of the samples collected is of no relevance to this study, as the samples were selected for their physical attributes. All data were collected and analysed in 2023 and 2024. Loose fragments of volcanic rock from the Eifel Volcanic Field or Krafla caldera were placed in a metal cup and progressively loaded axially to a target load before either 1) removing the load (called "dynamic stressing tests"); or 2) holding the load for 6h or 5 days (called "dynamic followed by static tests"). All experiments were conducted using an Instron uniaxial press, and all displacement data are corrected for the deformation of the loading column (compliance). During each experiment, acoustic emissions sensors attached to the side of the cup to monitor cracking events These data were collected to understand the compaction behaviour of volcanic edifices that consist of interbedded layers of variably loose/coherent materials.

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 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.

These data, presented in an excel spreadsheet, where each tab is a different sample (corresponding to the names in the publication), shows the fluid flow volume through time during a permeability measurement, plus the calculation of permeability. These permeability data were used in the publication by Weaver et al. 2023 (https://doi.org/10.1016/j.epsl.2023.118410) The data was collected and analysed at the University of Liverpool and each sample is made of volcanic glass fragments from Hrafntinnuhryggur, Iceland. The geographical location of the samples is here inconsequential for the dataset, the specific obsidian was chosen for its physical properties alone. The experiments were conducted and the data collected and analysed in 2021 and 2022 for publication in 2023. Experiments consisted of placing loose volcanic glass fragments in a crucible and placing the assembly in a high temperature oven (1006 oC) for variable amount of time to sinter them into a coherent material, before cooling and measuring permeability. The permeability measurement was made using the constant head permeability method with synthetic oil as a permeating fluid. This involves the filling of a given height of oil above the sample, creating an overburden that drives fluid flow. Details of the method are provided in detail in Weaver et al., 2023. The data were collected to assess the permeability evolution of fragmental systems undergoing diffusive outgassing, vesiculation and sintering to try to understand the longevity and impact of fragment-filled cracks present in volcanic environments.

Data shows the composition (in wt. %) and the modelled temperature-viscosity relationship (800-1600 degrees) for various generic compositions of magmas and variable water contents. These data are used for the viscosity curves shown in figure 11 of Kendrick and Lavallée, 2022 (https://doi.org/10.2138/rmg.2022.87.20). The data involve only idealised compositions, not real samples, and the data was compiled at the University of Liverpool, UK. These data were compiled in 2021. The generic magma compositions were input into the open access Viscosity calculator "GRD", available at; https://www.eoas.ubc.ca/~krussell/VISCOSITY/grdViscosity.html and the resulting temperature-viscosity relationship for each generic composition was generated, providing the lines used in Fig. 11 of the review paper Kendrick and Lavallée, 2022. These data help understanding the viscosity-temperature relationship of different composition magmas with different dissolved water content.

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.

Global dataset of active volcanoes along with active and potential geothermal sites. The dataset provides geographic coordinates of; 1) active volcanoes that have erupted in the last 10,000 years worldwide for use by Volcanic Ash Advisory Centers (VAAC) as compiled by the Smisthonian Institution (https://volcano.si.edu/projects/vaac-data/) ; 2) Geographic coordinates of active geothermal sites; 3) Geographic coordinates of potential geothermal sites. Both 2) and 3) were compiled by Coro and Trumpy, 2020 (https://doi.org/10.1016/j.jclepro.2020.121874). These data are compiled together in a map in the publication Lavallée et al., 2025 (https://doi.org/10.1017/s1062798724000292). The data compiled here are global datasets and the map was created at LMU Munich. The open-source data from Smisthonian Institution is collected and updated since 2013. All data used by Lavallée et al., 2025 were sourced and compiled in January 2024.The compilation was done using Matlab and a basemap provided by ESRI in 2009 The data were used to show how the potential and safe use of magma energy by geothermal power plants at recently active volcanoes could help with the energy transition.