Geometry and Time Dependencies of Intense Magma-Water Interaction Experiments on Decimeter and Meter Scale
Abstract
Explosive phreatomagmatic activity is caused by interaction of magma and surface water or groundwater. Experiments on a scale larger than decimeters are necessary to better understand how the known physical effects translate to the larger scales occurring in the natural processes. We present results of meter-scale experiments on intense magma-water interaction, that involve about 60kg melt (re-melted volcanic rock initially at ~1300ºC), and a water injection/mixing apparatus, which allows for time- and location controlled addition of water to the melt. Decimeter-scale experiments showed that a trigger mechanism (in that case a low-energy pellet shot from and air gun) massively increases the interaction intensity. For our meter-scale setup a hammer (4.54kg, 28J kinetic energy) is used as trigger which drives a plunger into the melt.
Results show that intense interaction can occur at relatively low magma/water mass ratios. Intensities measured in the meter-scale experiments can be compared to previously established decimeter-scale setup by automated video analysis.A timed trigger event can cause higher interaction intensity. However, some instances were observed in which intense interaction started before the trigger event. Finally we observed strong dependencies of interaction intensity on mixing speed, and the initial height of the melt column above the water mixing location.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.V51C..04S
- Keywords:
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- 8408 Volcano/climate interactions;
- VOLCANOLOGY;
- 8414 Eruption mechanisms and flow emplacement;
- VOLCANOLOGY;
- 8424 Hydrothermal systems;
- VOLCANOLOGY;
- 8427 Subaqueous volcanism;
- VOLCANOLOGY