This dataset comprises acoustic recordings of eruptive events at Strokkur Geyser, Iceland, collected during a field campaign from August 23–27, 2023. The data were recorded using four Chaparral M-60 UHP2 infrasound microphones with a flat frequency response from 0.05–200 Hz. The microphones were deployed in a semicircular array around the geyser pool, approximately 7.5 meters from its center. The signals were digitized using DiGOS Data-Cube3 digitizers with a sampling rate of 400 Hz, ensuring high-resolution capture of both low-frequency infrasound and high-frequency audio signals. Each recording spans approximately 2 ½ hours per day and is timestamped using GPS for precise temporal accuracy. The data are provided as miniSEED files with applied sensitivity, allowing direct calculation of sound pressure levels in Pascal (Pa). The exact locations for each sensor on each day are given below.
The dataset highlights acoustic signals associated with the growth, rupture, and disintegration of the water bulge preceding Strokkur’s eruptions. Distinct features, such as "M-shaped" infrasound waveforms, are evident and provide insight into the dynamic processes driving geyser eruptions.
The dataset offers a valuable resource for studying acoustic emissions during geyser activity, providing a high-resolution foundation for research on subsurface processes and fluid dynamics. It also facilitates comparative studies of geophysical signals in geysers and analogous volcanic systems.
August 23 (Small array configuration):
Recording times: 6:25 – 9:41 UTC (exact start times for each sensor may vary as they were started separately).
Sensor C3H: 64.31299, -20.30095
Sensor C3G: 64.31308, -20.30089
Sensor C3F: 64.31311, -20.30064
Sensor C3C: 64.31303, -20.30070
August 24 (Half circle around the geyser, until 8:36 UTC):
Recording times: 6:50 – 9:17 UTC (exact start times for each sensor may vary).
Sensor C3H: 64.31276, -20.30093
Sensor C3G: 64.31280, -20.30073
Sensor C3F: 64.31273, -20.30066
Sensor C3C: 64.31267, -20.30062
August 24 (After 8:36 UTC, modified configuration):
Sensor C3F moved to 64.313203, -20.301558 to record gas bubble sounds near another ground opening.
Sensor C3H: 64.31276, -20.30093
Sensor C3G: 64.31280, -20.30073
Sensor C3C: 64.31267, -20.30062
August 25 (Half circle around the geyser):
Recording times: 6:56 – 9:20 UTC (exact start times for each sensor may vary).
Sensor C3H: 64.31276, -20.30093
Sensor C3G: 64.31280, -20.30073
Sensor C3F: 64.31273, -20.30066
Sensor C3C: 64.31267, -20.30062
August 26:
No measurements were taken.
August 27 (Line configuration, before 8:01 UTC):
Recording times: 6:18 – 9:26 UTC (exact start times for each sensor may vary).
Sensor C3H: 64.31276, -20.30072
Sensor C3G: 64.31283, -20.30071
Sensor C3F: 64.31288, -20.30071
Sensor C3C: 64.31292, -20.30062
August 27 (After 8:01 UTC, returned to half circle around the geyser):
Sensor C3H: 64.31276, -20.30093
Sensor C3G: 64.31280, -20.30073
Sensor C3F: 64.31273, -20.30066
Sensor C3C: 64.31267, -20.30062
Explosive volcanic eruptions generate sound mostly in the infrasound (<20 Hz), but also in the acoustic (>20 and < 20k Hz) frequency range. Sound from volcanoes is recorded and used to describe quantitatively properties of the eruptive column, e.g. mass flux, and therefore it has monitoring purposes. However, a physical understanding of the underlying processes, their efficiency, and – maybe most importantly – the acting parameters like gas overpressure, absolute gas/magma volume, fragmentation depth and geometry of the plumbing system are unknown.
To shed light over the relationship between sound emissions and source conditions, we performed shock-tube experiments generating gas-only jets in an anechoic chamber testing the following conditions:
- 3, 4, 50, 75, 80 and 130 bar reservoir overpressure;
- 2.14 and 8.57 L/D non-dimensional reservoir volumes, where L is the length of the shock-tube reservoir and D the diameter;
- cylinder and two funnels with 15- and 30-degree flaring walls nozzle geometries.
The jets’ sound emissions were recorded with a near and far-field array composed of a total of 16 microphones.
This archive consists of the raw sound emission recording for the experiments performed. Thus, for each experiment, the user can access a single experiment. Each file is in CSV format. File names are self-explanatory following the format: Acoustic_[vent shape]_[pressure ratio]_[non-dimensional mass supply]_[YYYYMMDDTHHMMSS].csv. As an example, a user who wishes to access the data corresponding to an experiment performed at 50 bar, L/D 8, and a cylindrical nozzle will have to look for the file Acoustic_cyl_50bar_LD8_20160830T094809.csv. For detailed description, please refer to the associated data description pdf.
Core samples have been taken for complementary laboratory seismic measurements and mineralogical analyses on whole rock core from the COSC-1 borehole, Sweden (UTM 63.3124, 13.5259). These samples were used to provide and characterize the seismic properties (i.e., seismic velocities and anisotropy) of the drilled rocks from the highly metamorphosed and deformed Seve Nappe Complex, an orogenic thrust zone in the Scandinavian Caledonides, in central Sweden.
The laboratory seismic and mineralogical analysis in general comprises three distinct measurements (i.e., data sets), which will be described in detail in the following subsections: (1) P- and S-wave laboratory seismic measurements on three perpendicular core plugs, under different confining (hydrostatic) pressure conditions (10 + 6 samples), (2) Bulk mineralogy of core plugs using X-ray powder diffraction (XRD) and mineral chemical composition measurements using an electron probe micro-analyzer (EPMA, here microprobe), on 10 thin sections and (3) Microstructural investigations based on electron-backscatter diffraction analyses on 5 thin sections.
The laboratory seismic measurements were initially conducted on 6 samples by Wenning et al. (2016) and extended by another 10 samples by Kästner et al. (2020). Despite these authors were using the same sensor setup, the provided data files may differ due to individual acquisition parameters. Where different acquisition, processing, or calibration parameters are used this is indicated in the text using the abbreviations FK and QW referring to each examiner and their related sample measurements. International Geo Sample Numbers (IGSN) are provided for each core sample in the complete sample data table.