Publication Date:
2022-10-20
Description:
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Marine Geology & Geophysics at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution May 2022.
Description:
It is a scientifically accepted fact that the Earth’s climate is presently undergoing significant changes with the potential for immense negative impacts on human society. As evidence of these impacts become clear and common, it becomes ever more important to constrain the nature, magnitude, and speed of changes to Earth systems. A fundamentally important tool to this understanding is the Earth’s past, recorded in the geologic record. There, lie examples of climate change under various forcings: important data for understanding the fundamental dynamics of climate change on our planet. However, when a climate signal is
written in the geologic record, it is coded into the language of proxies and distorted by time. This thesis endeavors to decode that record using a variety of computational methods on a number of challenging proxies, to draw more information from the climate past than has previously been possible. First, machine learning and computer vision are used to decipher the primary, centimeter-scale textures of carbonate deposits in Searles Valley and Mono Lake, California. This work is able to connect facies in the tufa at Searles, grown during the Last Glacial Period, and those forming presently at Mono Lake. Next, the tracks of icebergs purged during Heinrich Events are simulated using the MIT General Circulation Model. This work, running multiple experiments exploring different aspects internal and external to the icebergs, reveals wind and sediment partitioning as centrally important to the spatial
extent of Heinrich Layers. Each of these works considers a traditional geologic archive – a carbonate facies, a marine sediment layer – and uses computational methods to approach that archive from a different perspective. By applying these new methods, more information can be gleaned from the geologic record, building a richer narrative of the Earth’s climate history. The final chapter of this thesis discusses effective teaching and strategies for building communities to support teaching practice in Earth Science departments.
Description:
This thesis work was funded by the MIT EAPS Rasmussen and Whiteman Fellowships, NSF Project Number NSF-EAR-1903544, and the WHOI Academic Programs Office.
Keywords:
Paleoclimate
;
Iceberg
;
Modeling
Repository Name:
Woods Hole Open Access Server
Type:
Thesis
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