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Infrasound (low‐frequency acoustic waves) has proven useful to detect and characterize subaerial volcanic activity, but understanding the infrasonic source during sustained eruptions is still an area of active research. Preliminary comparison between acoustic eruption spectra and the jet noise similarity spectra suggests that volcanoes can produce an infrasonic form of jet noise from turbulence. The jet noise similarity spectra, empirically derived from audible laboratory jets, consist of two noise sources: large‐scale turbulence (LST) and fine‐scale turbulence (FST). We fit the similarity spectra quantitatively to eruptions of Mount St. Helens in 2005, Tungurahua in 2006, and Kīlauea in 2018 using nonlinear least squares fitting. By fitting over a wide infrasonic frequency band (0.05–10 Hz) and restricting the peak frequency above 0.15 Hz, we observe a better fit during times of eruption versus non‐eruptive background noise. Fitting smaller overlapping frequency bands highlights changes in the fit of LST and FST spectra, which aligns with observed changes in eruption dynamics. Our results indicate that future quantitative spectral fitting of eruption data will help identify changes in eruption source parameters such as velocity, jet diameter, and ash content which are critical for effective hazard monitoring and response.

 

n Fall 2016, our NSF INCLUDES pilot grant enabled us to develop a partnership and network (SF CALL K–20 ALLIANCE) to design and align a K–20 pathway to CS careers by broadening participation (1) at the K–12 level; (2) across key transitions between K–12 and college and at the college level; and (3) by coordinating cross–sector stakeholder support for K–20 STEM student success. We are targeting K–20 for Broadening Participation (BP) to provide entry and reentry pathways for careers in computing. SF CALL also supports the development of student leadership groups to create inclusive communities of practice. Further supporting the transition from college to industry, SFSU has partnered with the SF Chamber of Commerce and the South SF city government to develop industry internships for CS students. This is on-going project that touches a very wide spectrum of inclusive computing education from K-20 to teacher preparation. In this paper, we focus on our efforts to build inclusive partnerships among all stakeholders and create a network able to achieve the given goals. 

Mount Cleveland is one of Alaska's most active volcanoes, yet little is known about the magmatic system driving persistent and dynamic volcanic activity. Volcanic gas and melt inclusion (MI) data from 2016 were combined to investigate shallow magmatic processes. SO₂emission rates were between 166 and 324 t/day and the H₂O/SO₂was 600 ± 53, whereas CO₂and H₂S were below detection. Olivine‐, clinopyroxene‐, and plagioclase‐hosted MIs have up to 3.8 wt.% H₂O, 514 ppm CO₂, and 2,320 ppm S. Equilibration depths, based on MI H₂O contents, suggest that a magmatic column extended from 0.5 to 3.0 km (~10–60 MPa). We used MI data to empirically model open‐system H‐C‐S degassing from 0 to 12 km and found that a column of magma between 0.5 and 3 km could produce the measured gas H₂O/SO₂ratio. However, additional magma deeper than 3 km is required to sustain emissions over periods greater than days to weeks, if the observed vent dimension is a valid proxy for the conduit. Assuming an initial S content of 2,320 ppm, the total magma supply needed to sustain the annual SO₂flux was 5 to 9.8 Mm³/yr, suggesting a maximum intrusive‐to‐extrusive ratio of 13:1. The model predicts degassing of <50 t/day CO₂for July 2016, which corresponds to a maximum predicted CO₂/SO₂of 0.2. Ultimately, frequent recharge from deeper, less degassed magma is required to drive the continuous activity observed over multiple years. During periods of recharge we would expect lower H₂O/SO₂and measurable volcanic CO₂.