Greenland Surface Roughness Retrieval and Status

Crevasses are important hydrologic conduits that evacuate surface melt water from the ice sheet, impacting glacier dynamics and contributing to global sea level rise. This thesis describes a novel processing pipeline for retrieving likely crevasse locations from ICESat waveform returns, and demonstr...

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Main Author: Grigsby, Shane P.
Format: Thesis
Language:English
Published: University of Colorado at Boulder 2019
Subjects:
Online Access:http://pqdtopen.proquest.com/#viewpdf?dispub=22615347
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spelling ftproquest:oai:pqdtoai.proquest.com:22615347 2023-05-15T16:21:23+02:00 Greenland Surface Roughness Retrieval and Status Grigsby, Shane P. 2019-01-01 00:00:01.0 http://pqdtopen.proquest.com/#viewpdf?dispub=22615347 ENG eng University of Colorado at Boulder http://pqdtopen.proquest.com/#viewpdf?dispub=22615347 Remote sensing thesis 2019 ftproquest 2021-03-13T17:37:10Z Crevasses are important hydrologic conduits that evacuate surface melt water from the ice sheet, impacting glacier dynamics and contributing to global sea level rise. This thesis describes a novel processing pipeline for retrieving likely crevasse locations from ICESat waveform returns, and demonstrates the methodology over a large land terminating drainage basin of the southwest Greenland ice sheet. This method is then extended and applied to the ice sheet periphery, and validated against optical imagery derived crevasse observations. The dataset described herein provides the earliest (years 2004 - 2006) baseline assessment of crevasse occurrence throughout the Greenland ice sheet periphery, and is a crucial comparison point for the ICESat-2 mission in assessing decadal length changes over the region. I find robust evidence of crevassing 135km inland at heights above 1800 meters, with weaker indications of surface anomalies occurring even higher on the ice sheet (up to 2300 meters). In addition, I provide both climatological (melt, runoff, surface mass balance), and mechanistic (strain, temperature, slope, thickness) parameter space distributions of crevassed areas. The distribution of crevasses suggests that in a warming climate, the ice sheet will have the potential to route water to englacial hydrologic systems at much higher elevations than previously thought, and could indicate significant ice sheet vulnerability in increasingly intense melt years. The spatial distribution of crevasses are highly coincident with ice lenses, and possibly exclusive of firn aquifers– a finding that could inform the distribution of crevasses through a range of climatological warming scenarios. Thesis glacier Greenland Ice Sheet PQDT Open: Open Access Dissertations and Theses (ProQuest) Greenland
institution Open Polar
collection PQDT Open: Open Access Dissertations and Theses (ProQuest)
op_collection_id ftproquest
language English
topic Remote sensing
spellingShingle Remote sensing
Grigsby, Shane P.
Greenland Surface Roughness Retrieval and Status
topic_facet Remote sensing
description Crevasses are important hydrologic conduits that evacuate surface melt water from the ice sheet, impacting glacier dynamics and contributing to global sea level rise. This thesis describes a novel processing pipeline for retrieving likely crevasse locations from ICESat waveform returns, and demonstrates the methodology over a large land terminating drainage basin of the southwest Greenland ice sheet. This method is then extended and applied to the ice sheet periphery, and validated against optical imagery derived crevasse observations. The dataset described herein provides the earliest (years 2004 - 2006) baseline assessment of crevasse occurrence throughout the Greenland ice sheet periphery, and is a crucial comparison point for the ICESat-2 mission in assessing decadal length changes over the region. I find robust evidence of crevassing 135km inland at heights above 1800 meters, with weaker indications of surface anomalies occurring even higher on the ice sheet (up to 2300 meters). In addition, I provide both climatological (melt, runoff, surface mass balance), and mechanistic (strain, temperature, slope, thickness) parameter space distributions of crevassed areas. The distribution of crevasses suggests that in a warming climate, the ice sheet will have the potential to route water to englacial hydrologic systems at much higher elevations than previously thought, and could indicate significant ice sheet vulnerability in increasingly intense melt years. The spatial distribution of crevasses are highly coincident with ice lenses, and possibly exclusive of firn aquifers– a finding that could inform the distribution of crevasses through a range of climatological warming scenarios.
format Thesis
author Grigsby, Shane P.
author_facet Grigsby, Shane P.
author_sort Grigsby, Shane P.
title Greenland Surface Roughness Retrieval and Status
title_short Greenland Surface Roughness Retrieval and Status
title_full Greenland Surface Roughness Retrieval and Status
title_fullStr Greenland Surface Roughness Retrieval and Status
title_full_unstemmed Greenland Surface Roughness Retrieval and Status
title_sort greenland surface roughness retrieval and status
publisher University of Colorado at Boulder
publishDate 2019
url http://pqdtopen.proquest.com/#viewpdf?dispub=22615347
geographic Greenland
geographic_facet Greenland
genre glacier
Greenland
Ice Sheet
genre_facet glacier
Greenland
Ice Sheet
op_relation http://pqdtopen.proquest.com/#viewpdf?dispub=22615347
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