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Heather B. Winslow, PhD

As an igneous petrologist, my research focuses on determining magmatic reservoir constraints and understanding crustal processes of volcanic systems using crystal records. I utilize mineral-scale techniques to investigate magmatic reservoir temperature and pressure estimates, as well as magma storage and transport timescales using diffusion chronometry. 

My Ph.D. research focused on the 2011-12 explosive-effusive eruption of Cordón Caulle, Chile in the Southern Andes. I used textural relationships, whole-rock chemistry, and mineral+glass chemistry to characterize mafic enclaves hosted within crystal-poor rhyolite lava flows. With this research, I worked on mush dynamics and explored under what conditions magmatic systems can efficiently fractionate. Along with basic chemistry, I determined timescales of mush storage along with cooling paths for the enclaves to be incorporated from the mush into the overlying rhyolite prior to the eruption. I also discerned the origin of chemical zoning in olivine from diffusion vs growth processes using stable isotopes of Fe and Mg.

My research here at HVO as a Mendenhall postdoc fellow switches gears from subduction zone environments to hotspots. I aim to understand the underlying plumbing system at Mauna Loa using multiple eruptions from its recent history including the November 2022 eruption. A big question I will be working toward is understanding the internal connection between summit and rift zone eruptions. Mauna Loa is the largest active volcano on Earth and understanding the size, depth, and innerworkings of the magmatic reservoir is important to interpreting pre-eruptive unrest signals.