Bubble ascent and rupture in mud volcanoes

Area of Science:

• Geophysics
• Fluid Dynamics
• Volcanology

Background:

• Large gas bubbles ascend and rupture at the surface of mud and lava pools.
• Bubble bursting releases volatiles and generates spatter, impacting volcanic degassing and edifice construction.

Purpose of the Study:

• Investigate the ascent and rupture dynamics of bubbles in viscous fluids.
• Understand the mechanisms of hole formation and expansion during bubble bursting.

Main Methods:

• Field observations at Pâclele Mici, Romania.
• Laboratory experiments using mud from the Imperial Valley, California.
• Numerical simulations and theoretical modeling.
• High-speed video documentation of bubble rupture.

Main Results:

• Bubbles ascend as elliptical caps, forming a dimple upon reaching the surface.
• Rupture initiates via nucleation of multiple, rapidly expanding circular holes.
• Hole expansion and sheet evolution follow a generalized Taylor-Culick theory, independent of fluid rheology.

Conclusions:

• The study elucidates the physics of bubble bursting in natural volcanic environments.
• The findings provide a theoretical framework applicable to understanding volcanic degassing and construction processes.
• The generalized Taylor-Culick theory accurately describes hole expansion during bubble rupture.