CAREER: Days before eruption: Tracking magma ascent pathways with a water-in-feldspar crystal clock

University Of Maryland, College Park, College Park MD

Investigators

Abstract

Scientists monitor seismicity at volcanoes to assess volcanic hazard and to forecast eruptions. It is difficult to forecast eruptions, in part because we do not fully understand the origin of volcano seismicity. Three eruptions of Mount Spurr (in Alaska) were preceded by interesting seismic signals. Investigators on this project will investigate the origin of these seismic signals by studying the migration pathways of magma in the days before the eruptions. The proposed work will track magma migration through the crust using gradients of water in crystals from the erupted volcanic ash. Results of this work will be shared with local high school students at an annual Volcano Summer School. At this summer school, students and future K-12 science teachers will learn about volcanoes and volcanic hazards. Classroom exercises created for this summer school will be shared with current and future K-12 science teachers. Water in feldspar has potential as a barometer and chronometer for tracking the migration and stalling of water-rich magmas in the hours to weeks prior to eruption. However, limited data is available for assessing the partitioning and diffusion behavior of water in feldspar. The proposed work would contribute new experiments that would explore water partitioning and diffusion in plagioclase feldspar as a function of water concentration, major and trace element composition, and oxygen fugacity. Water concentration gradients across plagioclase from three geophysically monitored eruptions of Mt. Spurr would then be used to assess the ascent paths of magmas in the hours to days before their eruption. These petrologic constraints on magma migration will be compared to the geophysical record of volcanic unrest, enabling us to test competing hypotheses regarding the staging of magma in the days before these significant eruptions. The proposed work provides a complete educational pathway from high school to graduate school: high school students from local schools and future STEM teachers will participate in an annual Volcano Summer School at University of Maryland (UMD); undergraduate researchers will lead the acquisition and interpretation of geochemical data from samples of the 1992 eruptions of Crater Peak; and a graduate student will lead the experimental research. Results of the proposed work will be integrated into UMD classes and the Volcano Summer School in the form of data-driven exercises. These exercises will be shared online and with future STEM educators via the participation of undergraduate students from UMD’s “Terrapin Teachers” program as paid teaching assistants at the Volcano Summer School. 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.