How Do Volcanoes Work: Reconciling the Cold and Warm Storage Models

Arizona State University, Scottsdale AZ

Investigators

Abstract

Volcanic eruptions are some of the most destructive natural hazards on Earth, costing the lives of hundreds of people and destroying many infrastructures all over the world. The question of identifying the processes occurring beneath volcanoes is of crucial significance, as such knowledge is necessary to better predict destructive eruptions. An important aspect of petrology and geochemistry is to develop new tools that allow researchers to assess how volcanic magma chambers work and evolve. Unfortunately, applications of these tools give contrasting answers that lead to contradictory models in the literature for the storage and eruption capacity of volcanic reservoirs. This project seeks to reconcile the community by providing a common ground where proponents of different models and tools can meet and learn, Only an open-minded, reconciled approach would allow the identification of trends among different volcanoes and improve our understanding of volcanic systems that pose a threat to human life and infrastructure. This project broadens the participation of underrepresented groups, and supports a graduate student. In the past couple of years, two models have emerged for the evolution of silicic magma systems: Cold Storage, based on geospeedometry applications, and Warm Storage, mostly based on thermal models and zircon geochronology/geochemistry studies. Both models have critical implications on the mechanisms of volcanic eruptions, and are highly debated within the petrology community. A lot of efforts are currently allotted in the literature to discuss the merits of the various tools used in both cold and warm storage models; however, none of those tools have been applied together on the same volcanic systems. Therefore, it is unclear if the different storage conditions documented so far in the literature are linked to the analytical methods used, or reflect a more fundamental problem, that physical mechanisms in volcanic systems are too variable for the establishment of a unified model. In this project, we propose to apply analytical methods used in the past to bolster the arguments for both cold and warm storage together on the same volcanic systems and address the most fundamental question, do all volcanoes of similar size and tectonic context work the similarly. We propose to apply Sr diffusion in plagioclase (cold storage tool) together with zircon geochronology/geochemistry (warm storage tool) on three different arc volcanoes that were previously used to bolster either the cold or warm storage argument, the St. Lucia Soufriere Volcanic Center, Mt. Hood (Cascade Mountain Range) and the Okataina Caldera (Taupo Volcanic Arc, New Zealand). Our work will concentrate on both lavas and cogenetic plutonic enclaves from the three case studies. By combining results from all set of tools, samples and eruptive events, we will draw a more comprehensive thermal history for these three volcanoes, identify common features in volcanic reservoirs of similar size and setting and test the cold and warm storage tools. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.