English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Conference Paper

Influence of crystallization on magmatic degassing and eruptive dynamics

Authors

Theurel,  Anna
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Collombet,  Marielle
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Burgisser,  Alain
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Martel,  Caroline
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in GFZpublic
Supplementary Material (public)
There is no public supplementary material available
Citation

Theurel, A., Collombet, M., Burgisser, A., Martel, C. (2023): Influence of crystallization on magmatic degassing and eruptive dynamics, XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) (Berlin 2023).
https://doi.org/10.57757/IUGG23-0545


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016957
Abstract
Eruptive dynamics of silicic volcanoes are highly controlled by the possibility of gases escaping from the magmatic column. A recent study (Collombet et al., 2021) shows that outgassing probably occurs deeper in the magmatic column (several kilometers) than previously thought. This early outgassing is linked to bubble channeling which occurs when crystal content reaches 40 to 70 vol% (Parmigiani et al., 2017). This particular crystal content should allow the magma to become permeable at lower gas content than initially thought. We propose to model the evolution of bubble coalescence and channelization in synthetic magmas using decompression experiments in internally-heated autoclave. In these experiments, we propose to test the influence of crystal size and crystal content on the permeability in a gas-poor mixture. Preliminary results suggest the presence of permeability at 10% bulk porosity for a bulk crystal content of 50 vol%. It confirms that one important parameter for the formation of permeability in gas-poor magma is the number density of bubbles, controlled by decompression rate (Toramaru, 1995). Based on our preliminary results and assumptions on the future samples, the role and process of nucleation are then to be considered seriously in the problematic of channelization and further in magmatic degassing. The parametrized behavior of bubble coalescence and permeability at low gas volume fraction and high crystal fraction will then be integrated into large-scale numerical model to predict the evolution of degassing in magmatic columns.