Glaciology Commons^™

Research Sites Get Closer To Field Camps Over Time: Informing Environmental Management Through A Geospatial Analysis Of Science In The Mcmurdo Dry Valleys, Antarctica, Stephen M. Chignell, Madeline E. Myers, Adrian Howkins, Andrew Fountain

Geology Faculty Publications and Presentations

As in many parts of the world, the management of environmental science research in Antarctica relies on cost-benefit analysis of negative environmental impact versus positive scientific gain. Several studies have examined the environmental impact of Antarctic field camps, but very little work looks at how the placement of these camps influences scientific research. In this study, we integrate bibliometrics, geospatial analysis, and historical research to understand the relationship between field camp placement and scientific production in the McMurdo Dry Valleys of East Antarctica. Our analysis of the scientific corpus from 1907–2016 shows that, on average, research sites have become less …

Late Pleistocene And Early Holocene Sea-Level History And Glacial Retreat Interpreted From Shell-Bearing Marine Deposits Of Southeastern Alaska, Usa, James F. Baichtal, Alia J. Lesnek, Risa J. Carlson, Nicholas S. Schmuck, Jane L. Smith, Dennis J. Landwehr, Jason P. Briner

Publications and Research

We leverage a data set of >720 shell-bearing marine deposits throughout southeastern Alaska (USA) to develop updated relative sea-level curves that span the past ~14,000 yr. This data set includes site location, elevation, description when avail-able, and 436 14C ages, 45 of which are published here for the first time. Our sea-level curves suggest a peripheral forebulge developed west of the retreating Cordilleran Ice Sheet (CIS) margin between ca. 17,000 and 10,800 calibrated yr B.P. By 14,870 ± 630 to 12,820 ± 340 cal. yr B.P., CIS mar-gins had retreated from all of southeastern Alaska’s fjords, channels, and passages. At …

A Case Study Using 2019 Pre-Monsoon Snow And Stream Chemistry In The Khumbu Region, Nepal, Heather M. Clifford, Mariusz Potocki, Inka Koch, Tenzing Sherpa, Mike Handley, Elena Korotkikh, Douglas Introne, Susan Kaspari, Kimberley Miner, Tom Matthews, Baker Perry, Heather Guy, Ananta Gajurel, Praveen Kumar Singh, Sandra Elvin, Aurora C. Elmore, Alex Tait, Paul A. Mayewski

Geological Sciences Faculty Scholarship

This case study provides a framework for future monitoring and evidence for human source pollution in the Khumbu region, Nepal. We analyzed the chemical composition (major ions, major/trace elements, black carbon, and stable water isotopes) of pre-monsoon stream water (4300–5250 m) and snow (5200–6665 m) samples collected from Mt. Everest, Mt. Lobuche, and the Imja Valley during the 2019 pre-monsoon season, in addition to a shallow ice core recovered from the Khumbu Glacier (5300 m). In agreement with previous work, pre-monsoon aerosol deposition is dominated by dust originating from western sources and less frequently by transport from southerly air mass …

Letters To A Glacier; An Experiment And Critique Of M. Jackson’S Glacier-Ruins Narrative, Lily Fife Schaeufele

Independent Study Project (ISP) Collection

“Words are events, they do things, change things. They transform both speaker and hearer; they feed energy back and forth and amplify it. They feed understanding or emotion back and forth and amplify it.” —Ursula K. Le Guin

Letters to a Glacier; The Buoy Project Isafjordur is an ongoing invitation to the people of Isafjordur to write a letter to a specific glacier in Iceland onto a collection of discarded buoys gathered from the Isafjorudur and Bolungarvik junk yards. Over a period of two days on November 9th and 10th, I actively invited customers in the local cafe Heimabyggð to …

Science Is For Everybody: A Resource For Understanding Glaciers, Climate, And Modeling, Emma Watson

Independent Study Project (ISP) Collection

Climate change threatens the existence of glaciers worldwide. In order to properly interact with these changing systems, we must first understand them. Glacial models provide an excellent way to do this; however, the language and mathematical concepts used in their creation is generally inaccessible to a common audience. This project presents an online resource for a general audience to interact with climate science, glaciology, and glacial modeling. Long term goals for the project include the incorporation of a glacial model of Drangajökull, Vestfirðir, NW Iceland. As such, focus for the project includes a literature review of glaciers, Drangajökull in particular, …

Climate On The Blanca Massif, Sangre De Cristo Mountains, Colorado, Usa, During The Last Glacial Maximum, Keith A. Brugger, Eric M. Leonard, Kurt A. Refsnider, Peter Dolan

Geology Publications

Temperature-index modeling is used to determine the magnitude of temperature depression on the Blanca Massif, Colorado, required to maintain steady-state mass balances of nine reconstructed glaciers at their extent during the Last Glacial Maximum (LGM). The mean temperature depression thus determined is ~8.6 +0.7/−0.9 degrees C where the uncertainties account for those inherent in the glacier reconstructions, in model parameters (e.g., melt factors), and possible modest changes in LGM precipitation. Associated equilibrium-line altitudes (ELAs) exhibit a statistically significant directional dependency being lower toward the north and east. Under the assumption that regional temperature change was uniform, required changes in precipitation …

Kinematics Of The Exceptionally-Short Surge Cycles Of Sít’ Kusá (Turner Glacier), Alaska, From 1983 To 2013, Andrew Nolan, William Kochtitzky, Ellyn M. Enderlin, Robert Mcnabb, Karl J. Kreutz

Geosciences Faculty Publications and Presentations

Glacier surges are periodic episodes of mass redistribution characterized by dramatic increases in ice flow velocity and, sometimes, terminus advance. We use optical satellite imagery to document five previously unexamined surge events of Sít’ Kusá (Turner Glacier) in the St. Elias Mountains of Alaska from 1983 to 2013. Surge events had an average recurrence interval of ~5 years, making it the shortest known regular recurrence interval in the world. Surge events appear to initiate in the winter, with speeds reaching up to ~25 m d⁻¹. The surges propagate down-glacier over ~2 years, resulting in maximum thinning of ~100 …

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 …

Biis: The Last British Ice Sheet, A Review Of The Most Recent Major Glaciation Of Great Britain And Ireland, Benediktas Gaskevicius

Honors College Theses

The British Irish Ice Sheet was a substantial ice mass covering the British Isles during the most recent glaciation that ended around 11,700 years ago. Oftentimes referred to as the BIIS, it is subdivided into two sections, a western and eastern side that covered Great Britain and Ireland, with the Irish basin in the middle. Some notable areas of study around Great Britain and Ireland include the ’Bizzle’ in Northern England, which was transformed by the effects of the eastern margin of the BIIS, the Carstair Kames in Scotland, a locality known internationally for its esker system, The Minch region …

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 …

Glacier Clear Ice Bands Indicate Englacial Channel Microbial Distribution, Gilda Varliero, Alexandra Holland, Gary L. A. Barker, Marian L. Yallop, Andrew G. Fountain, Alexandre M. Anesio

Geology Faculty Publications and Presentations

Distant glacial areas are interconnected by a complex system of fractures and water channels which run in the glacier interior and characterize the englacial realm. Water can slowly freeze in these channels where the slow freezing excludes air bubbles giving the ice a clear aspect. This ice is uplifted to the surface ablation zone by glacial movements and can therefore be observed in the form of clear surface ice bands. We employed an indirect method to sample englacial water by coring these ice bands. We were able, for the first time, to compare microbial communities sampled from clear (i.e. frozen …

Deriving Melt Rates At A Complex Ice Shelf Base Using In Situ Radar: Application To Totten Ice Shelf, Irena Vaňková, Sue Cook, J. Paul Winberry, Keith W. Nicholls, Benjamin K. Galton-Fenzi

Geological Sciences Faculty Scholarship

A phase-sensitive radar (ApRES) was deployed on Totten Ice Shelf to provide the first in situ basal melt estimate at this dynamic East Antarctic ice shelf. Observations of internal ice dynamics at tidal time scales showed that early arrivals from off-nadir reflectors obscure the true depth of the ice shelf base. Using the observed tidal deformation, the true base was found to lie at 1,910–1,950-m depth, at 350–400 m greater range than the first reflection from an ice-ocean interface. The robustness of the basal melt rate estimate was increased by using multiple basal reflections over the radar footprint, yielding a …

Radio-Echo Sounding And Waveform Modeling Reveal Abundant Marine Ice In Former Rifts And Basal Crevasses Within Crary Ice Rise, Antarctica, Trevor R. Hillebrand, Howard Conway, Michelle Koutnik, Carlos Martin, John Paden, J. Paul Winberry

Geological Sciences Faculty Scholarship

Crary Ice Rise formed after the Ross Ice Shelf re-grounded ~1 kyr BP. We present new ice-penetrating radar data from two systems operating at center frequencies of 7 and 750 MHz that confirm the ice rise is composed of a former ice shelf buried by subsequent accumulation. Stacks of englacial diffraction hyperbolas are present almost everywhere across the central ice rise and extend up to ~350 m above the bed. In many cases, bed reflections beneath the diffraction hyperbolas are obscured for distances up to 1 km. Waveform modeling indicates that the diffraction hyperbolas are likely caused by marine ice …

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 …

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, …

Migration Of The Frozen/Melted Basal Boundary Linked To ~100 Kilometers Of Ice Margin Retreat, Western Greenland Ice Sheet, Aidan Ripley Stansberry

Graduate Student Theses, Dissertations, & Professional Papers

The geometry and thermal structure of western Greenland ice sheet have evolved over the last 11 kyr in response to Holocene climate. Evolution of the frozen and melted fractions of the bed associated with the ice sheet retreat over this time frame remains unclear. We address this question using a thermo-mechanically coupled flowline model to simulate a 11 kyr period of ice sheet retreat in west central Greenland. Our transient flow-line modeling includes high order stresses, thermally active bedrock, a well-informed climate that is constrained by an established record of ice margin retreat. We partition the transient heat balance into …

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 …

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.

Subsurface Architecture Of Alpine Icy Debris Fans: Integration Of Ground-Penetrating Radar And Surface Observations In Alaska And New Zealand, Robert W. Jacob, Jeffrey M. Trop, R. Craig Kochel

Faculty Journal Articles

Icy debris fans (IDFs) are extremely dynamic supraglacial landforms at the mouths of bedrock catchments between valley glaciers and icecaps. Recent studies quantified the nature, pace, and volume of mass flow processes contributing ice and sediment to IDFs by integrating field observations, drone and time-lapse imagery, and terrestrial laser scanning. New geophysical data presented herein characterize the subsurface architecture of IDFs along the McCarthy Glacier in Alaska and the Douglas, La Perouse, and Mueller Glaciers in New Zealand. Ground Penetrating Radar (GPR) profiles and soundings from field surveys during 2013–2015 provide stratigraphic evidence of the following subsurface processes important in …