Preprints

Filtering by Subject: Glaciology

Modeling sediment compaction beneath ice lenses during frost heave

Aaron Grey Stubblefield, Colin R. Meyer, Alan Rempel, et al.

Published: 2024-07-13
Subjects: Applied Mathematics, Earth Sciences, Glaciology, Hydrology, Physical Sciences and Mathematics, Soil Science

Frost heave occurs when the ground swells during freezing conditions due to the growth of ice lenses in the subsurface. The mechanics of ice-infiltrated sediment, or frozen fringe, influences the formation and evolution of ice lenses. As the frozen fringe thickens during freezing, progressive unloading can result in dilation of the pore space and the formation of new ice lenses. Compaction can [...]

Uranium-series isotopes as tracers of physical and chemical weathering in glacial sediments from Taylor Valley, Antarctica

Graham Harper Edwards, Gavin Piccione, Terrence Blackburn, et al.

Published: 2024-07-04
Subjects: Earth Sciences, Geochemistry, Glaciology, Soil Science

The McMurdo Dry Valleys of Antarctica formed by extensive glacial erosion, yet currently exhibit hyperarid polar conditions characterized by limited chemical and physical weathering. Efficient chemical weathering occurs when moisture is available, and polythermal subglacial conditions may accommodate ongoing mechanical weathering and valley incision. Taylor Valley hosts several Pleistocene [...]

Mechanisms for upstream migration of firn aquifer drainage: preliminary observations of Helheim Glacier, Greenland

Jessica Mejia, Kristin Poinar, Colin R. Meyer, et al.

Published: 2024-07-03
Subjects: Glaciology

Surface meltwater can influence subglacial hydrology and ice dynamics if it reaches the ice sheet’s base. Firn aquifers store meltwater and drain into wide crevasses marking the aquifer’s downstream boundary, indicating water from firn aquifers drives hydrofracture to establish the upglacier-most surface-to-bed hydraulic connections. Yet, sparse observations limit our understanding of the [...]

Increasing precipitation will offset the impact of warming air temperatures on glacier volume loss in the monsoon-influenced Himalaya until 2100 CE

Ann Rowan, Anya M Schlich-Davies, Andrew N Ross, et al.

Published: 2024-06-27
Subjects: Glaciology

Himalayan glaciers are projected to shrink by over 50% this century due to rising air temperatures. However, the impact of future precipitation change on glacier evolution remains uncertain. Here we explore these precipitation effects by simulating the future evolution of Khumbu Glacier in the monsoon-influenced Himalaya until 2300 CE. Khumbu Glacier is committed by historical warming to volume [...]

Fracture criteria and tensile strength for natural glacier ice calibrated from remote sensing observations of Antarctic ice shelves

Sarah Wells-Moran, Meghana Ranganathan, Brent Minchew

Published: 2024-06-24
Subjects: Glaciology

The conditions under which ice fractures and calves icebergs from Antarctic ice shelves are poorly understood due largely to a lack of relevant observations. Though previous studies have estimated the stresses at which ice fractures in the laboratory and through sparse observations, there remains significant uncertainty in the applicability of these results to naturally deforming glacier ice on [...]

Automatic identification of streamlined subglacial bedforms using machine learning: an open-source Python approach

Ellianna Abrahams, Marion A. McKenzie, Fernando Pérez, et al.

Published: 2024-06-16
Subjects: Geomorphology, Glaciology, Statistical Models

Subglacial processes exert a major control on ice streaming. Constraining subglacial conditions thus allows for more accurate predictions of ice mass loss. Due to the difficulty in observing large‐scale conditions of the modern subglacial environment, we turn to geologic records of ice streaming in deglaciated environments. Morphometric values of streamlined subglacial bedforms provide valuable [...]

Investigating the Dynamic History of a Promontory Ice Rise using Radar Data

M. Reza Ershadi, Reinhard Drews, Jean-Louis TISON, et al.

Published: 2024-06-07
Subjects: Geophysics and Seismology, Glaciology

Ice rises hold valuable records revealing the ice dynamics and climatic history of Antarctic coastal areas from the Last Glacial Maximum to today. This history is often reconstructed from isochrone radar stratigraphy and simulations focusing on Raymond arch evolution beneath the divides. However, this relies on complex ice-flow models where many parameters are unconstrained by observations. Our [...]

Unique In-situ Measurements from Greenland Fjord Show Winter Freshening by Subglacial Melt

Karina Hansen, Nanna B Karlsson, Penelope How, et al.

Published: 2024-05-08
Subjects: Earth Sciences, Glaciology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics

The interaction between glacier fronts and ocean waters is one of the key uncertainties for projecting future ice mass loss. Direct observations at glacier fronts are sparse but studies indicate that the magnitude and timing of freshwater fluxes are crucial in determining fjord circulation, ice frontal melt and ecosystem habitability. Particularly wintertime dynamics are severely understudied due [...]

The role of thermal notch erosion in forcing localised calving failure and short-term increases in velocity at a lake-terminating glacier in southeast Iceland

Nathaniel Ross Baurley, Jane K Hart

Published: 2024-04-10
Subjects: Glaciology

We utilised repeat high-resolution UAV-SfM surveys, alongside terrestrial photography acquired in-situ, to investigate, for the first time, how localised calving failure can drive short-term increases in velocity at a lake-terminating glacier. This data was acquired over five days in early July 2019, and across 11 days in July 2021, to provide insights into a suite of processes that have been [...]

Concepts and capabilities of the Instructed Glacier Model

Guillaume Jouvet, Samuel Cook, Guillaume Cordonnier, et al.

Published: 2024-04-05
Subjects: Glaciology

We present the concept and capabilities of IGM (https://github.com/jouvetg/igm), a Python-based modeling tool designed for efficiently simulating glacier evolution across various scales. IGM integrates ice thermomechanics, climate-driven surface mass balance, mass conservation, and other processes. Within IGM, the update of all physical model components involves a series of mathematical [...]

DAS to Discharge: Using Distributed Acoustic Sensing (DAS) to infer glacier runoff

John-Morgan Manos, Dominik Gräff, Eileen Martin, et al.

Published: 2024-02-08
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics

Observations of glacier melt and runoff are of fundamental interest in the study of glaciers and their interactions with their environment. Considerable recent interest has developed around distributed acoustic sensing (DAS), a sensing technique which utilizes Rayleigh backscatter in fiber optic cables to measure the seismo-acoustic wavefield in high spatial and temporal resolution. Here, we [...]

Characteristics of dynamic thickness change across diverse outlet glacier geometries and basal conditions

Donglai Yang, Kristin Poinar, Sophie Nowicki, et al.

Published: 2024-01-30
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics

Outlet glaciers in Greenland are undergoing retreat and diffusive thinning in response to external forcings, but the rates and magnitudes of these responses differ from glacier to glacier for unclear reasons. We test how changes in ice overburden pressure and basal lubrication affect diffusive thinning rates and their spatial patterns by conducting numerical experiments over various idealized [...]

Subtemperate regelation exhibits power-law premelting

Colin R. Meyer, Julia Bellamy, Alan Rempel

Published: 2024-01-13
Subjects: Fluid Dynamics, Glaciology, Other Physics

Wire regelation is a common tabletop demonstration of the pressure-dependence of the ice melting temperature where loaded wires move from top to bottom through a block of ice, yet leaves the block intact. With the background temperature fixed at the bulk melting point $\sim0\,^{\circ}$C, the elevated ice and liquid pressures beneath the wire cause melting because of the negative Clapeyron slope, [...]

Metrological approach for permafrost temperature measurements

Graziano Coppa, Francesca Sanna, Luca Paro, et al.

Published: 2024-01-12
Subjects: Climate, Environmental Monitoring, Glaciology

Permafrost degradation is a growing direct impact of climate change. Detecting permafrost reductions, in terms of its extension, deepening of the active layer and rise of the base is fundamental to capture the magnitude of trends and address actions and warnings. Temperature profiles in permafrost allow direct understanding of the status of the frozen ground layer and its evolution in time. The [...]

Evidence that seismic anisotropy captures upstream palaeo ice fabric: Implications on present day deformation at Whillans Ice Stream, Antarctica

Justin Leung, Thomas Samuel Hudson, John-Michael Kendall, et al.

Published: 2023-11-16
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics

Understanding deformation and slip at ice streams, which are responsible for 90% of Antarctic ice loss, is vital for accurately modelling large-scale ice flow. Ice preferred crystal orientation fabric (COF) has a first-order effect on ice stream deformation. For the first time, we use shear-wave splitting (SWS) measurements of basal icequakes at Whillans Ice Stream (WIS), Antarctica, to determine [...]

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