Glaciology Commons^™

Examining Summertime Melt And Temperatures In The North Pacific Cordillera, Ingalise Kindstedt

Electronic Theses and Dissertations

Temperature changes in glaciated regions are of immediate concern for estimates of future sea level rise. Alaska and the surrounding region contain over 40 mm of potential sea level rise in its many alpine glaciers, which are experiencing some of the highest rates of mass loss globally. However, records of both past and present temperatures in the region’s alpine sectors are sparse and limited in temporal and spatial extent. Here I examine the application of MODIS land surface temperatures and layers of refrozen melt in ice cores as temperature indicators in the St. Elias and Alaska Ranges. First, I ...

Drought-Induced Biomass Burning As A Source Of Black Carbon To The Central Himalaya Since 1781 Ce As Reconstructed From The Dasuopu Ice Core, Joel D. Barker, Susan Kaspari, Paulo Gabrielli, Anna Wegner, Emilie Beaudon, M. Roxana Sierra-Hernández, Lonnie Thompson

Geological Sciences Faculty Scholarship

Himalayan glaciers are melting due to atmospheric warming, with the potential to limit access to water for more than 25 % of the global population that resides in these glacier meltwater catchments. Black carbon has been implicated as a factor that is contributing to Himalayan glacier melt, but its sources and mechanisms of delivery to the Himalayas remain controversial. Here, we provide a 211-year ice core record spanning 1781–1992 CE for refractory black carbon (rBC) deposition from the Dasuopu glacier ice core that has to date provided the highest-elevation ice core record (7200 m). We report an average rBC concentration ...

Glaciology, Geomorphology Giant Roger Hooke Passes Away At 82, Division Of Marketing And Communications

General University of Maine Publications

Roger Hooke, beloved University of Maine mentor and researcher and giant in the fields of glaciology and geomorphology, died March 10 [2021] at the age of 82.

Hooke joined the School of Earth and Climate Sciences and Climate Change Institute in 2000 as a research professor and adviser. One of Hooke's interests during his time at UMaine involved examining what glacial landforms in Maine revealed about the Laurentide Ice Sheet.

The Role Of Glaciers In Hydropower Production In Nepal, Shakti P.C., Ishwar Pun, Rocky Talchabhadel, Darshan Kshetri

Journal of Asian Energy Studies

Nepal is a mountainous country rich in water resources, with huge potential for hydropower generation. The Department of Electricity Development (DoED), which sits within the Nepalese Ministry of Energy, has published Guidelines for Study of Hydropower Projects to set out the official standards for the detailed study of hydropower projects in Nepal. The guide is regularly revised, with the latest revision having taken place in 2018, in order to ensure the long-term sustainability of the projects. Among the key issues considered are the linkages between glaciers and hydropower projects in Nepal under a changing environment. The formation of new glacial ...

Rock Glaciers And Related Cold Rocky Landforms: Overlooked Climate Refugia For Mountain Biodiversity, Stefano Brighenti, Scott Hotaling, Debra S. Finn, Andrew G. Fountain, Masaki Hayashi, David Herbst, Jasmine E. Saros, Lusha M. Tronstad, Constance I. Millar

Geology Faculty Publications and Presentations

Mountains are global biodiversity hotspots where cold environments and their associated ecological communities are predicted to be threatened by climate warming. Considerable research attention has been devoted to understanding the ecological effects of alpine glacier and snowfield recession. However, much less attention has been given to identifying climate refugia in mountain ecosystems where present-day environmental conditions will be maintained, at least in the near-term, as other habitats change. Around the world, montane communities of microbes, animals, and plants live on, adjacent to, and downstream of rock glaciers and related cold rocky landforms (CRL). These geomorphological features have been overlooked in ...

Temperature Variance Portends And Indicates The Extent Of Abrupt Climate Shifts, Christine Ramadhin, Chuixiang Yi, George Hendrey

Publications and Research

Here, we show a discernable increase in temperature variance before a glacial termination by both the Ansari-Bradley test and the moving variance methods plus introduce the idea that there is a correlation between the peak variance and peak temperature increase. The behavior of temperature variance shows potential as a useful tool in analyzing time series data of Earth systems to assess the risk and extent of an upcoming abrupt climate transition.

Model Data For 'Co2 And Tectonic Controls On Antarctic Climate And Ice-Sheet Evolution In The Mid-Miocene', Anna Ruth Halberstadt

Data and Datasets

This is the data repository associated with the manuscript "CO₂ and Tectonic Controls on Antarctic Climate and Ice-Sheet Evolution in the Mid-Miocene" containing all model output files relevant to the project. We use an ensemble of asynchronously coupled climate - ice sheet - vegetation model simulations spanning a range of CO₂ concentrations, Transantarctic Mountain uplift scenarios, and glacial/interglacial climatic conditions to identify climate and ice-sheet conditions consistent with Antarctic mid-Miocene terrestrial and marine geological records. Details about the content of the data repository can be found in the readme.txt file located in the repository.

Carbonaceous Matter In The Atmosphere And Glaciers Of The Himalayas And The Tibetan Plateau: An Investigative Review, Chaoliu Li, Fangping Yan, Shichang Kang, Caiqing Yan, Zhaofu Hu, Pengfei Chen, Shaopeng Gao, Chao Zhang, Cenlin He, Susan Kaspari, Aron Stubbins

Geological Sciences Faculty Scholarship

Carbonaceous matter, including organic carbon (OC) and black carbon (BC), is an important climate forcing agent and contributes to glacier retreat in the Himalayas and the Tibetan Plateau (HTP). The HTP – the so-called “Third Pole” – contains the most extensive glacial area outside of the polar regions. Considerable research on carbonaceous matter in the HTP has been conducted, although this research has been challenging due to the complex terrain and strong spatiotemporal heterogeneity of carbonaceous matter in the HTP. A comprehensive investigation of published atmospheric and snow data for HTP carbonaceous matter concentration, deposition and light absorption is presented, including how ...

Core Handling, Transportation And Processing For The South Pole Ice Core (Spicecore) Project, Joseph M. Souney, Mark S. Twickler, Murat Aydin, Eric J. Steig, T.J. Fudge, Leah V. Street, Melinda R. Nicewonger, Emma C. Kahle, Jay A. Johnson, Tanner W. Kuhl, Kimberly A. Casey, John M. Fegyveresi, Richard M. Nunn, Geoffrey M. Hargreaves

Earth Systems Research Center

An intermediate-depth (1751 m) ice core was drilled at the South Pole between 2014 and 2016 using the newly designed US Intermediate Depth Drill. The South Pole ice core is the highest-resolution interior East Antarctic ice core record that extends into the glacial period. The methods used at the South Pole to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the National Science Foundation Ice Core Facility (NSF-ICF), and the methods used to process and sample the ice at the NSF-ICF are described. The South Pole ice core exhibited minimal brittle ice ...

Mass And Number Size Distributions Of Rbc In Snow And Firn Samples From Pine Island Glacier, West Antarctica, Luciano Marquetto, Susan Kaspari, Jefferson Cardia Simões

Geological Sciences Faculty Scholarship

An extended‐range Single Particle Soot Photometer (SP2) coupled to a Marin‐5 nebulizer was used to measure the refractory black carbon (rBC) mass and number size distributions in 1,004 samples from a West Antarctica snow/firn core. The SP2 was calibrated using Aquadag and a Centrifugal Particle Mass Analyzer for BC particles ranging from 0.5 to 800 fg. Our results indicate a significant contribution of rare, large particles of mass‐equivalent diameter (D_BC) > 500 nm to the total rBC mass (36%), while small particles (D_BC < 100 nm) are abundant but contribute <8% to total rBC mass. We observed a primary mass median diameter of 162 ± 40 nm, smaller than reported for snow in other regions of the globe but similar to East Antarctica rBC size distributions. In addition, we observed other modes at 673, 1,040, and >1,810 nm (uncontained mode). We compared two sets of ...

Sharp Contrasts In Observed And Modeled Crevasse Patterns At Greenland’S Marine Terminating Glaciers, Ellyn M. Enderlin, Timothy C. Bartholomaus

Geosciences Faculty Publications and Presentations

Crevasses are affected by and affect both the stresses and the surface mass balance of glaciers. These effects are brought on through potentially important controls on meltwater routing, glacier viscosity, and iceberg calving, yet there are few direct observations of crevasse sizes and locations to inform our understanding of these interactions. Here we extract depth estimates for the visible portion of crevasses from high-resolution surface elevation observations for 52 644 crevasses from 19 Greenland glaciers. We then compare our observed depths with those calculated using two popular models that assume crevasse depths are functions of local stresses: the Nye and ...

Sea Surface Temperature Across The Subarctic North Pacific And Marginal Seas Through The Past 20,000 Years: A Paleoceanographic Synthesis, Catherine V. Davis, Sarah E. Myhre, Curtis Deutsch, Beth Caissie, Summer Praetorius, Marisa Borreggine, Robert Thunell

Geological and Atmospheric Sciences Publications

Deglacial sea surface conditions in the subarctic North Pacific and marginal seas are the subject of increasing interest in paleoceanography. However, a cohesive picture of near-surface oceanography from which to compare inter and intra-regional variability through the last deglaciation is lacking. We present a synthesis of sea surface temperature covering the open North Pacific and its marginal seas, spanning the past 20 ka using proxy records from foraminiferal calcite (δ18O and Mg/Ca) and coccolithophore alkenones (Uk’37). Sea surface temperature proxies tend to be in agreement through the Holocene, though Uk’37 records are often interpreted as warmer than ...

A Periglacial Landsystem Analysis In The Canadian High Arctic: A Tool For Planetary Geomorphology, Chimira Nicole Andres

Electronic Thesis and Dissertation Repository

Permafrost underlies 50% of Canada’s terrain and underlies 24% of the Earth’s total land area. It is a major driving force in the generation and evolution of patterned ground landforms such as polygons, stone circles, mud boils, and stripes, etc. that are seen on both the surface of the Earth and Mars, specifically in periglacial domains. The distribution of subsurface ice in these landforms (i.e. polygonal terrain) on Earth is a key constraint on past climate and process-form relationships in high arctic and periglacial regions. These landforms also have the potential of storing ice in the subsurface ...

Massachusetts Beach Grain Size And Slope Data, Jonathan Woodruff, Nicholas Venti, Stephen Mabee, Alycia Ditroia, Douglas Beach

Data and Datasets

This data repository contains grain size and beach face slope data from approximately 100 paired summer and winter transects collected along 18 separate beaches in southern New England. The study is focused to beaches of Massachusetts, which represents a particularly unique section of the Northeastern US coast in that it: 1) lies at the interface between New England’s paraglacial lowlands and Mid-Atlantic Coastal Plain, 2) spans both micro- and meso- tidal regimes, 3) encompasses a wide range of seasonally varying wave conditions, and 4) contains a diverse array of geomorphic and grain size characteristics. Between 2 and 10 intertidal ...

Controls On Subglacial Rock Friction: Experiments With Debris In Temperate Ice, A. C. Thompson, Neal R. Iverson, L. K. Zoet

Geological and Atmospheric Sciences Publications

Glacier sliding has major environmental consequences, but friction caused by debris in the basal ice of glaciers is seldom considered in sliding models. To include such friction, divergent hypotheses for clast‐bed contact forces require testing. In experiments we rotate an ice ring (outside diameter = 0.9 m), with and without isolated till clasts, over a smooth rock bed. Ice is kept at its pressure‐melting temperature, and meltwater drains along a film at the bed to atmospheric pressure at its edges. The ice pressure or bed‐normal component of ice velocity is controlled, while bed shear stress is measured ...

Drilling Operations For The South Pole Ice Core (Spicecore) Project, Jay A. Johnson, Tanner W. Kuhl, Grant Boeckmann, Chris Gibson, Joshua Jetson, Zachary Meulemans, Kristina Slawny, Joseph M. Souney

Earth Systems Research Center

Over the course of the 2014/15 and 2015/16 austral summer seasons, the South Pole Ice Core project recovered a 1751 m deep ice core at the South Pole. This core provided a high-resolution record of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. The drilling and core processing were completed using the new US Intermediate Depth Drill system, which was designed and built by the US Ice Drilling Program at the University of Wisconsin–Madison. In this paper, we present and discuss the setup, operation, and performance of the drill system.

Sea-Ice Production And Air/Ice/Ocean/Biogeochemistry Interactions In The Ross Sea During The Pipers 2017 Autumn Field Campaign, S. F. Ackley, S. Stammerjohn, T. Maksym, M. Smith, J. Cassano, P. Guest, J.-L. Tison, B. Delille, B. Loose, Peter N. Sedwick, L. Depace, L. Roach, J. Parno

OEAS Faculty Publications

The Ross Sea is known for showing the greatest sea-ice increase, as observed globally, particularly from 1979 to 2015. However, corresponding changes in sea-ice thickness and production in the Ross Sea are not known, nor how these changes have impacted water masses, carbon fluxes, biogeochemical processes and availability of micronutrients. The PIPERS project sought to address these questions during an autumn ship campaign in 2017 and two spring airborne campaigns in 2016 and 2017. PIPERS used a multidisciplinary approach of manned and autonomous platforms to study the coupled air/ice/ocean/biogeochemical interactions during autumn and related those to spring ...

Automated Terminus Detection For Greenland's Peripheral Marine-Terminating Glaciers, Julia Liu

Boise State University Theses and Dissertations

Changes in the length of marine-terminating glaciers strongly influence the mass balance of glaciers, ice caps, and ice sheets. Currently, quantification of glacier length change through measurement of terminus position relies on time-consuming and subjective manual mapping techniques, limiting our ability to understand the dynamics controlling glacier terminus changes. I developed an automated method of mapping glacier terminus positions in satellite imagery using observations from a representative sample of Greenlands peripheral glaciers. The method is adapted from the 2D Wavelet Transform Modulus Maxima (WTMM) segmentation method, which has been used previously for image segmentation in biomedical and other applied science ...

Analysis Of Antarctic Peninsula Glacier Frontal Ablation Rates With Respect To Iceberg Melt-Inferred Variability In Ocean Conditions, M. C. Dryak, E. M. Enderlin

Geosciences Faculty Publications and Presentations

Marine-terminating glaciers on the Antarctic Peninsula (AP) have retreated, accelerated and thinned in response to climate change in recent decades. Ocean warming has been implicated as a trigger for these changes in glacier dynamics, yet little data exist near glacier termini to assess the role of ocean warming here. We use remotely-sensed iceberg melt rates seaward of two glaciers on the eastern and six glaciers on the western AP from 2013 to 2019 to explore connections between variations in ocean conditions and glacier frontal ablation. We find iceberg melt rates follow regional ocean temperature variations, with the highest melt rates ...

Evaluation Of Iceberg Calving Models Against Observations From Greenland Outlet Glaciers, Tristan Amaral, Timothy C. Bartholomaus, Ellyn M. Enderlin

Geosciences Faculty Publications and Presentations

Frontal ablation processes at marine‐terminating glaciers are challenging to observe and difficult to represent in numerical ice flow models, yet play critical roles in modulating ice sheet mass balance. Current ice sheet models typically rely on simple iceberg calving models to prescribe either terminus positions or iceberg calving rates, but the relative accuracies and uncertainties of these calving models remain largely unconstrained at the ice sheet scale. Here, we evaluate six published iceberg calving models against spatially and temporally diverse observations from 50 marine‐terminating outlet glaciers in Greenland. We seek the single model that best reproduces observed conditions ...