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Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Modeling And Measuring Water Level Fluctuations In The Greenland Ice Sheet: How Moulin Life Cycle And Shape Can Inform Us On The Subglacial Drainage System., Celia Trunz Jul 2021

Modeling And Measuring Water Level Fluctuations In The Greenland Ice Sheet: How Moulin Life Cycle And Shape Can Inform Us On The Subglacial Drainage System., Celia Trunz

Graduate Theses and Dissertations

In the ablation zone of land terminating sectors of the Greenland Ice Sheet (GrIS), water pressures at the bed control ice motion variability on diurnal and seasonal timescales. During the melt season, large volumes of surface meltwater access the ice-bed interface through moulins.Moulins are large vertical shafts that connect the supraglacial and subglacial drainage systems. Moulins form when a crevasse intersects a surface meltwater source that can drive hydrofracture to the bed of the ice sheet. Upon reaching the bed, meltwater can establish and sustain an efficient, channelized drainage system. Due to the technical impossibility of physically exploring underwater passages …


Investigating The Hydrology Of The Western Greenland Ice Sheet: Spatiotemporal Variability And Implications On Ice-Dynamics, Jessica Z. Mejia Apr 2021

Investigating The Hydrology Of The Western Greenland Ice Sheet: Spatiotemporal Variability And Implications On Ice-Dynamics, Jessica Z. Mejia

USF Tampa Graduate Theses and Dissertations

Since the 1990's the Greenland Ice Sheet (GrIS) has been losing mass at an accelerating rate in response to climatic warming and is currently the largest terrestrial contributor to sea-level rise. While ice sheet models agree the GrIS will continue losing mass throughout the century, there are significant uncertainties associated with future sea-level rise contributions. Predicting the GrIS's response to future climate warming scenarios is limited by gaps in our understanding of the links between ice sheet hydrology and dynamics. Meltwater produced on the ice surface flows within supraglacial streams that deliver it to crevasses or moulins—vertical conduits extending from …


Inference Of Surface Velocities From Oblique Time Lapse Photos And Terrestrial Based Lidar At The Helheim Glacier, Franklyn T. Dunbar Ii Jan 2021

Inference Of Surface Velocities From Oblique Time Lapse Photos And Terrestrial Based Lidar At The Helheim Glacier, Franklyn T. Dunbar Ii

Graduate Student Theses, Dissertations, & Professional Papers

Using time dependent observations derived from terrestrial LiDAR and oblique
time-lapse imagery, we demonstrate that a Bayesian approach to glacial motion es-
timation provides a concise way to incorporate multiple data products into a single
motion estimation procedure effectively producing surface velocity estimates with
an associated uncertainty. This approach brings both improved computational effi-
ciency, and greater scalability across observational time-frames when compared to
existing methods. To gauge efficacy, we apply these methods to a set of observa-
tions from the Helheim Glacier, a critical actor in contemporary mass loss trends
observed in the Greenland Ice Sheet. We find that …