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.
Active volcanoes frequently show substantial topographic changes and variable eruption intensity, style and/or directionality. Here we provide high-resolution photogrammetric data sets of Stromboli’s crater terrace collected during 5 field campaigns between May 2019 and January 2020 supporting the publication Schmid, M, Kueppers U, Ricci T, Taddeucci J, Civico R and Dingwell DB (2021) “Characterizing Vent and Crater Shape Changes at Stromboli: Implications for Risk Areas”.
The aerial imagery for the photogrammetric reconstruction of the crater terrace geometry was acquired by UAVs (DJI Phantom 4Pro+ & Mavic 2 Pro) and processed with the commercial software Metashape by Agisoft. The created digital elevation models (DEMs), orthomosaics and 3D models were used to characterize vent and crater shape and their changes through time. The activity during the observational period was characterized by elevated Strombolian activity and two paroxysms on 3 July and 28 August 2019.
Our study revealed significant changes to crater terrace morphology and vent geometry on various time scales and the strong control of vent geometry on the directionality of explosions.