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dc.contributor.authorRobert, Zena V.
dc.date.accessioned2021-12-17T18:45:03Z
dc.date.available2021-12-17T18:45:03Z
dc.date.issued2021-08
dc.identifier.urihttp://hdl.handle.net/11122/12629
dc.descriptionThesis (M.S.) University of Alaska Fairbanks, 2021en_US
dc.description.abstractThe northeastern portion of Denali National Park and Preserve (DENA) is a high-altitude (800 m - 1400 m asl), subarctic (63°N) environment where climate is now changing rapidly. This landscape is underlain by discontinuous permafrost (perennially frozen ground), and the recent surge of mass movements occurring there could be the result of permafrost thaw. Some of these mass movements have the potential to damage the Denali Park Road, alter the flow of groundwater and stream systems, destroy vegetation cover, and endanger the half a million visitors that DENA receives every year. The purpose of this study to understand how mass movements in DENA are being affected by different aspects of climate change, to assess the role of permafrost thaw in their dynamics, to determine when DENA's landscape experienced periods of geomorphic instability in the past, and to better understand the potential trajectory of the landscape changes now occurring. Results show that many ongoing mass movements in DENA are reactivations of landslides that were active earlier in the Holocene (the last 11,700 years). A representative example is the Mile 35 landslide, a complex mass movement initiated along the Park Road during the summer of 2016 after a quiescent period of around 4000 years. I use a combination of remote sensing and field surveys to establish a four-year timeline of this landslide's movements and then compared these observations to records of weather and climate. Results suggest that freeze/thaw processes and extreme rainfall events strongly affect the initiation and subsequent movements of the Mile 35 landslide. Looking farther back in time, lichenometric dating of rockfalls in DENA suggests their frequency peaked 100 to 200 years ago during the initial stages of climate warming at the end of the Little Ice Age. These findings suggest that warming climate triggers a predictable sequence of mass movement responses in DENA, with the initial warming triggering a bout of more frequent rockfalls, and then, as warming penetrates deeper into the ground, causes deep-seated mass movements like the Mile 35 landslide. These results suggest that cycles of hillslope stability and instability in response to climate change are characteristic, long-term features of DENA's ecosystems and dynamic ecosystems and landscapes.en_US
dc.description.sponsorshipAlfred P. Sloan Indigenous Graduate Program, Schmidt Charitable Trust, Aleut Foundation, Alaska Native Science and Engineering Program, Alaska Geological Society, Geological Society of America, National Science Foundation/Geological Society of America's Graduate Student Geoscience Grant #12766-20 funded by NSF Award #1949901en_US
dc.language.isoen_USen_US
dc.subjectMass-wastingen_US
dc.subjectGlobal warmingen_US
dc.subjectDenali National Park and Preserveen_US
dc.subjectClimatic changesen_US
dc.subjectLandslidesen_US
dc.subjectRockslidesen_US
dc.subject.otherMaster of Science in Geoscienceen_US
dc.titleImpacts of climate change on mass movements in Denali National Park and Preserve, Alaskaen_US
dc.typeThesisen_US
dc.type.degreemsen_US
dc.identifier.departmentDepartment of Geosciencesen_US
dc.contributor.chairMann, Daniel
dc.contributor.committeeFarquharson, Louise
dc.contributor.committeeRomanovsky, Vladimir
dc.contributor.committeeMeyer, Franz
dc.contributor.committeeMaio, Chris
refterms.dateFOA2021-12-17T18:45:04Z


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