Sahand Hajimirza, Rice University-Can Bubbles from Volcanic Eruptions Tell Us Volcanic Conduits?
- Thursday, Apr 29, 2021 12:00 PM
- https://stanford.zoom.us/j/92246012053 Passcode: 467202
- General Public
- Geophysics Department
Dept. of Earth, Environmental and Planetary Sciences at Rice University.
Can bubbles from explosive volcanic eruptions tell us about the shape of volcanic conduits?
The flow of magma in the volcanic plumbing system determines the style of volcanic eruptions. However, little is known about the rise of magma during explosive volcanic eruptions, despite their tremendous destructive potential. In particular, the size and shape of volcanic conduit that connects magma reservoir to the surface is arguably the most important and at the same time the least understood facet of volcanic systems. The deeper reaches of volcanic conduits have neither been observed directly nor imaged geophysically. In this presentation, first I will present the development of a physics-based numerical model of bubble nucleation and growth in rhyolitic magma and calibration of the model with experiments. Second, by integrating the bubble nucleation model with fluid dynamics of magma ascent during Plinian explosive eruptions, I will show that to match the number density and size distribution of bubbles recorded in erupted volcanic rocks, volcanic conduits must gradually narrow upward resembling a broad cupola shape atop magma reservoir. Lastly, I will briefly talk about the potential future directions in the physics-based modeling of conduit flow in explosive volcanic eruptions.
https://stanford.zoom.us/j/92246012053 Passcode: 467202