News & Events

PhD defense: Sarah Crump

Monday, March 11, 2019, 3:30PM - 5:30PM

Speaker

Sarah Crump

Location:

SEEC room S228 (Sievers Room)

Title

Deconvolving climatic and non-climatic controls on Holocene glacier and ecological change on Baffin Island, Arctic Canada

Abstract

The Arctic is warming at double the rate of the rest of the planet. Pronounced warming is causing dramatic changes in glacier extent and tundra ecosystems, which in turn contribute to positive feedbacks that further amplify climate change. My PhD research leverages the geologic record to assess how past climate variability drove changes in the cryosphere and biosphere on Baffin Island, Arctic Canada, over the last ~10,000 years. In this talk, I will present two chapters of my dissertation that are focused on Arctic environmental change under the warm but somewhat turbulent climate of the early Holocene, a partial analogue for future climate change. In the first chapter, I use cosmogenic 10Be ages from moraines to explore how glaciers responded to abrupt, centennial-scale cooling events between 10 and 8 ka. In the second chapter, I combine ancient plant DNA from lake sediment with biomarker-derived paleotemperature estimates to reconstruct postglacial ecosystem change on southern Baffin Island. This combination of molecular proxies provides tight constraints on the colonization timing of dwarf birch and highlights a previously unrecognized migration lag relative to local deglaciation and warmest temperatures of the Holocene. In both cases, I will examine the role of both climatic and non-climatic factors in controlling the rate and style of Arctic landscape responses to climate change.

Audience

Open to the public.