Phys.org May 10, 2024
Researchers in the UK demonstrated that the size, frequency, and composition of large-scale, explosive volcanic eruption can be explained by processes in long-lived, high-crystallinity source reservoirs that control the episodic creation of large volumes of eruptible silicic magma and its delivery to the subvolcanic chamber where it is stored before eruption. A large volume of low-crystallinity silicic magma which remains trapped until buoyancy causes magma-driven fractures to propagate into the overlying crust, allowing rapid magma transfer from the reservoir into the chamber. Ongoing melt percolation in the reservoir accumulates a new magma layer and the process repeats. According to the researchers their results suggest that buoyancy, rather than crystallinity, is the key control on magma delivery from the source reservoir. They identified an optimum reservoir size for the largest silicic eruptions that is consistent with data from natural systems and explained why larger magnitude eruptions are not observed on Earth… read more. Open Access TECHNICAL ARTICLE
Simulated pressure around an elliptical magma body in viscous crust. Credit: SCIENCE ADVANCES, Vol 10, Issue 19, 10 May 2024