Exploring Complexities in the Earth’s Upper Mantle and Connecting Approaches to Inclusivity in the Earth Sciences

Krueger, Hannah Elaine

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Year:: 2023
Contributor:: Krueger, Hannah Elaine (creator); Fischer, Karen (Advisor); Dalton, Colleen (Reader); Saal, Alberto (Reader); Lau, Harriet (Reader); Russell, Josh (Reader); Brown University. Department of Earth, Environmental, and Planetary Sciences (sponsor)
Genre:: theses
Subject:: Antarctica; mantle metasomatism; Seismology; Upper Mantle; Lithosphere; Inclusivity; Cratons
Extent:: 17, 319 p.

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Abstract:: This PhD thesis presents a comprehensive exploration of Earth’s upper mantle from global and regional perspectives, with a particular emphasis on the stable cores of continents, or cratons. The geophysics chapters of this thesis are complimented by a commentary on improving inclusivity within the field of geosciences. With a diverse set of seismological techniques, the chapters begin by exploring the layering structure of the cratonic upper mantle globally using S-to-P converted waves. This work led to the discovery of intriguing patterns in layering but lacks a comprehensive understanding of seismic velocity structure. To pursue this, my collaborators and I add Rayleigh phase velocities to resolve absolute shear velocity in addition to layering using a Bayesian joint inversion. This more holistic view of the global cratonic upper mantle revealed that mantle upwellings of carbonate melts provide a broad explanation for the heterogeneous velocity increases and decreases we observe within the cratonic lithosphere. Therefore, we conclude that layering in the cratonic lithosphere that has long been debated, may have a common origin. Continuing in the pursuit of a holistic understanding of mantle structure, we present phase velocities and preliminary attenuation maps for regions spanning the tectonically active West Antarctica and stable East Antarctica. While attenuation results are currently preliminary, the eventual joint interpretation of shear velocity and attenuation will provide constraints on the character of the Antarctic mantle. Despite shifting focus away from geophysics, the final chapter of this thesis maintains the motivation for holistic understanding of complex topics using multi-faceted approaches. Specifically, we present a model that explores the roles of and interconnections between community engagement, teaching and learning, and community atmosphere in cultivating inclusive geoscience spaces. Through this model we develop organized, nuanced, and actionable approaches for improving inclusivity in the geosciences based on the analysis of three years of panel discussions.
Notes:: Thesis (Ph. D.)--Brown University, 2023

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Citation

Krueger, Hannah Elaine, "Exploring Complexities in the Earth’s Upper Mantle and Connecting Approaches to Inclusivity in the Earth Sciences" (2023). Earth, Environmental and Planetary Sciences Theses and Dissertations. Brown Digital Repository. Brown University Library. https://repository.library.brown.edu/studio/item/bdr:4v93z9ac/

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Earth, Environmental and Planetary Sciences Theses and Dissertations

Theses and Dissertations for the Earth, Environmental and Planetary Sciences department.
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