Glaciology Commons^™

Evidence For Ephemeral Middle Eocene To Early Oligocene Greenland Glacial Ice And Pan-Arctic Sea Ice, Aradhna Tripati, Dennis Darby

OES Faculty Publications

Earth's modern climate is defined by the presence of ice at both poles, but that ice is now disappearing. Therefore understanding the origin and causes of polar ice stability is more critical than ever. Here we provide novel geochemical data that constrain past dynamics of glacial ice on Greenland and Arctic sea ice. Based on accurate source determinations of individual ice-rafted Fe-oxide grains, we find evidence for episodic glaciation of distinct source regions on Greenland as far-ranging as ~68°N and ~80°N synchronous with ice-rafting from circum-Arctic sources, beginning in the middle Eocene. Glacial intervals broadly coincide with reduced CO_{2 …}

Internal Composition, Structure, And Hydrological Significance Of Rock Glaciers In The Eastern Cascades, Washington, Adam Riffle

All Master's Theses

Low summer river base flow places a strain on natural and economic resources of the Eastern Cascades. A major contributor to stream flow in this region is snow pack which has declined over the past few decades because of a warming climate. In addition, glacial runoff, which contributes significantly to base flow in summer dry periods, will diminish from glacial recession. However, rock glaciers, because their internal ice (i.e., permafrost) is insulated by an outer debris layer, react slowly to climate change, thus acting as sinks for ice and liquid water storage in mountain environments. This study utilized ground penetrating …

The Impact Of Reduced Arctic Sea Ice Extent On Cryospheric Snowfall, Alexander Carne

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Satellite observations show that sea ice extent in the Arctic has been declining from 1979 through present day, reaching record minimum extents in 2007 and 2012. Reduced sea ice extent allows for greater expanses of open water to interact with the Arctic atmosphere, potentially leading to changes in the Arctic climate. The greatest declines in Arctic sea ice extent have occurred in summer and autumn. During these seasons, it is likely that the decrease in Arctic sea ice extent led to an increase in atmospheric sensible and latent heat fluxes, possibly leading to increases in Arctic temperature and moisture. Increases …

Understanding And Developing Estimates Based On Practical Foundation Methods For Alaska's Discontinuous Permafrost Region, Paul P. Dennison

Theses and Dissertations

This research uses a quantitative analysis to develop a family of curves and a calculator for potential foundation thresholds in the discontinuous permafrost region of Alaska. The United States Pacific Command (PACAF) is bolstering the region by advocating for the F-35, KC-46, and the newly proposed long-range bomber to be stationed in Alaska. These next generation aircrafts and warfighters will need new facilities and beddown plans to efficiently and effectively carry out their mission. The biggest obstacle in the region is permafrost; this unique polar phenomenon is found throughout the northern half of Alaska. Fairbanks in particular has multiple military …

Raritan Formation (Upper Cretaceous), Long Island, New York: Sedimentological And Geochemical Assessment, Nazrul I. Khandaker, Arif Sikder, Stanley Schleifer, Xin-Chen Liu, Carlos E. Castano Londano, Joseph B. Mcgee Turner

Publications and Research

The lithology of the Upper Cretaceous Raritan Formation (RF) consists of two members: an upper clay member (Raritan clay) and a lower unit, the Lloyd Sand Member. RF is unconformably overlain by upper Pleistocene glacial deposits. The RF consists of stratified white, light- to dark-gray, and red beds and lenses of clay, silt, and sand; lignite and pyrite are common. Variegated, thin to thickly-bedded Lloyd sandstone (LS) is considered to be one of the extensive regional aquifers in Long Island and interpreted to be nearshore, fluvio-deltaic deposit. Proximity to fluvial axes and active deltaic lobes plays an important role in …

Giovanni Badino (1953-2017), Arrigo Cigna, Paolo Forti

International Journal of Speleology

Short obituary of Giovanni Badino.

Odu Scientists Address Antarctic Ice Melt Affecting Sea Levels, Miasia Osbey

News Items

No abstract provided.

The Uppermost Mantle Seismic Velocity And Viscosity Structure Of Central West Antarctica, J. P. O'Donnell, K. Selway, A. A. Nyblade, R. A. Brazier, D. A. Wiens, S. Anandakrishnan, R. C. Aster, Audrey D. Huerta, T. Wilson, J. Paul Winberry

All Faculty Scholarship for the College of the Sciences

Accurately monitoring and predicting the evolution of the West Antarctic Ice Sheet via secular changes in the Earth's gravity field requires knowledge of the underlying upper mantle viscosity structure. Published seismic models show the West Antarctic lithosphere to be ∼70–100 km thick and underlain by a low velocity zone extending to at least ∼200 km. Mantle viscosity is dependent on factors including temperature, grain size, the hydrogen content of olivine, the presence of partial melt and applied stress. As seismic wave propagation is particularly sensitive to thermal variations, seismic velocity provides a means of gauging mantle temperature. In 2012, a …

The Geography Of Glaciers And Perennial Snowfields In The American West, Andrew G. Fountain, Bryce Glenn, Hassan J. Basagic

Geology Faculty Publications and Presentations

A comprehensive mid-20th century inventory of glaciers and perennial snowfields (G&PS) was compiled for the American West, west of the 100° meridian. The inventory was derived from U.S. Geological Survey 1:24,000 topographic maps based on aerial photographs acquired during 35 years, 1955–1990, of which the first 20 years or more was a cool period with little glacier change. The mapped features were filtered for those greater than 0.01 km². Results show that 5036 G&PS (672 km², 14 km³) populate eight states, of which about 1276 (554 km^2, 12 km³) are glaciers. …

Microfeatures Of Modern Sea-Ice-Rafted Sediment And Implications For Paleo-Sea-Ice Reconstructions, Kristen E. St. John, Sandra Passchier, Brooke Tantillo, Dennis Darby, Lance Kearns

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Distinguishing sea-ice-rafted debris (SIRD) from iceberg-rafted debris is crucial to an interpretation of ice-rafting history; however, there are few paleo-sea-ice proxies. This study characterizes quartz grain microfeatures of modern SIRD from the Arctic Ocean, and compares these results with microfeatures from representative glacial deposits to potentially differentiate SIRD from ice-rafted sediments which have been recently subjected to glacial processes. This allows us to evaluate the use of grain microfeatures as a paleo-sea-ice proxy. SIRD grains were largely subrounded, with medium relief, pervasive silica dissolution and a high abundance of breakage blocks and microlayering. The glacial grains were more angular, with …

The Potential Effects Of Percolating Snowmelt On Palynological Records From Firn And Glacier Ice, Michael E. Ewin, Carl A. Reese, Matthew A. Nolan

Faculty Publications

The effects of meltwater percolation on pollen in snow, firn and glacial ice are not fully understood and currently hamper the use of pollen in ice-core studies of paleoclimate. Several studies have suggested that, due to grain size, pollen is not mobilized by meltwater transport. However, these findings contradict many ice-core pollen studies that show pollen concentrations in snow and firn are much higher than concentrations found in the ice layers they eventually form. This study addresses one aspect of this question by investigating whether meltwater percolation can effectively transport pollen within a snowpack. We used nine Styrofoam coolers filled …

Evidence For Late Pliocene Deglacial Megafloods From Giant Sediment Waves In The Northern Gulf Of Mexico, Zexuan Wang

Masters Theses & Specialist Projects

Laurentide Ice Sheet outburst floods to the Gulf of Mexico have been mainly documented based on deep-sea cores, especially the megafloods, only during the last several interglacial episodes in the late Pleistocene. The paleoclimatic significance of giant sedimentary structures developed under unconfined Froude-supercritical turbidity currents in subaqueous settings is considerably under-examined. This research extensively documents >20-km-wide and 200-m-thick Plio-Pleistocene giant sediment waves for the first time on the northern Gulf of Mexico continental slope using 3D seismic data, which show waveform morphology in unprecedented detail. The results suggest that such large-scale bedforms were formed under sheet-like unconfined Froudesupercritical turbidity currents …

Assessing Seasonal And Spatial Variability In The Hydrogeochemistry Of Glacial Meltwater In Iceland, Anisha Tuladhar

Masters Theses & Specialist Projects

A detailed comparative geochemical characterization of three different types of Iceland glacial systems was conducted during June, August, and October, 2016. The study was carried out at a total of 11 outlet glacier rivers flowing from the icecaps Vatnajökull, Eyjafjallajökull, and Mýrdalsjökull. A total of 75 grab samples were collected (25 for each sampling period). The hydrogeochemical variations of Icelandic glacial meltwater are influenced by volcanic activity, temporal changes, and geographical location, which differed between the sampling sites within the glaciers and icecaps. Lower pH range, and comparatively higher and variable specific conductivity, SO4, S and F is linked to …

Toward The Development Of A 10be Chronology Of Glaciation In The Mosquito Range, Colorado: A Progress Report, Noah Bensen, Keith A. Brugger

Undergraduate Research Symposium 2017

The Last Glacial Maximum (LGM) in the Rocky Mountain region occurred about 21 ka (20,000 years before present). However, dated glacial chronologies suggest that while LGM glacier advances in individual ranges in Colorado were somewhat synchronous, retreat from their maximum extents was asynchronous, varying between ~20 and 15 ka or later. The precise timing and spatial variation of glacier advance and retreat provides insights into LGM climate change and is necessary to calibrate climate models. To better understand the timing of the LGM in the Mosquito Range in Colorado, we collected 12 samples from granitic boulders on moraine crests in …

Gravity And Passive Seismic Methods Used Jointly For Understanding The Subsurface In A Glaciated Terrain: Dowling And Maple Grove Quadrangles, Barry County, Michigan, Scott A. Feldpausch

Masters Theses

The Horizontal to Vertical Spectral Ratio (HVSR) passive, single sensor seismic technique has been used together with gravimetry to study the topography hidden below the glacial drift of two 7.5’ quadrangles in Barry Co., MI. 265 stations were observed with both instruments along roads at nominal spacings of about 0.4 to 0.8 km. Occasional water wells and oil wells with documented penetrations of the base of glacial were used to calibrate the local power law regression calibration. This was also compared with the statewide calibration curve previously established. Results are presented as maps of Simple Bouguer Anomaly, Residual Bouguer Anomaly, …

Regional Greenland Accumulation Variability From Operation Icebridge Airborne Accumulation Rradar, Gabriel Lewis, Erich Osterberg, Robert Hawley, Brian Whitmore

Dartmouth Scholarship

The mass balance of the Greenland Ice Sheet (GrIS) in a warming climate is of critical interest to scientists and the general public in the context of future sea-level rise. An improved understanding of temporal and spatial variability of snow accumulation will reduce uncertainties in GrIS mass balance models and improve projections of Greenland's contribution to sea-level rise, currently estimated at 0.089 ± 0.03 m by 2100. Here we analyze 25 NASA Operation IceBridge accumulation radar flights totaling  >  17 700 km from 2013 to 2014 to determine snow accumulation in the GrIS dry snow and percolation zones over the past …

Analyzing Glacier Surface Motion Using Lidar Data, Jennifer W. Tellig, Craig Glennie, Andrew G. Fountain, David C. Finnegan

Geology Faculty Publications and Presentations

Understanding glacier motion is key to understanding how glaciers are growing, shrinking, and responding to changing environmental conditions. In situ observations are often difficult to collect and offer an analysis of glacier surface motion only at a few discrete points. Using light detection and ranging (LiDAR) data collected from surveys over six glaciers in Greenland and Antarctica, particle image velocimetry (PIV) was applied to temporally-spaced point clouds to detect and measure surface motion. The type and distribution of surface features, surface roughness, and spatial and temporal resolution of the data were all found to be important factors, which limited the …

Assessment Of Nasa Airborne Laser Altimetry Data Using Ground-Based Gps Data Near Summit Station, Greenland, Kelly M. Brunt, Robert L. Hawley, Eric R. Lutz, Michael Studinger

Dartmouth Scholarship

A series of NASA airborne lidars have been used in support of satellite laser altimetry missions. These airborne laser altimeters have been deployed for satellite instrument development, for spaceborne data validation, and to bridge the data gap between satellite missions. We used data from ground-based Global Positioning System (GPS) surveys of an 11 km long track near Summit Station, Greenland, to assess the surface–elevation bias and measurement precision of three airborne laser altimeters including the Airborne Topographic Mapper (ATM), the Land, Vegetation, and Ice Sensor (LVIS), and the Multiple Altimeter Beam Experimental Lidar (MABEL). Ground-based GPS data from the monthly …

Novel Methods For Quantifying Spatio-Temporal Change In Glaciated And Subaqueous Environments, Jordan Mertes

Dissertations, Master's Theses and Master's Reports

In many scientific fields, it is important to actively develop new approaches to monitoring and quantifying changes within different systems. Often adapting existing tools or applying techniques from alternative fields can greatly improve our ability to monitor spatial and temporal changes. In this dissertation, I present four studies aimed at demonstrating new innovative ways at improving our ability to observe and quantify changes occurring on glaciers, submerged cultural resources (SCRs) and supraglacial lakes by using technology such as Structure from Motion + Multi-view stereo photogrammetry (SfM) and ground penetrating radar (GPR) surveying combined with facies analysis.

I have successfully reconstructed …

Tidal And Structural Controls On Seismic Events Near The Grounding Line At Beardmore Glacier, Antarctica, Jade Cooley

All Master's Theses

Here I report seismic events occurring over a three-week period during the 2013-2014 austral summer near the grounding line of Beardmore Glacier, Antarctica. The ~24000 events over this time frame had a noticeable temporal pattern that correlates well with the principally diurnal tides of Antarctica. Falling and rising tide each accounted for nearly equal occurrence of events, and most (~42%) events occurred in the last third of any tidal cycle. Event epicenters were located using beamforming, and display a spatial pattern of two distinct clusters. Appearance of event location clusters differ on rising and falling tide. I theorize that, due …

150 Years Of Light Absorbing Impurity Deposition On South Cascade Glacier, Washington State Usa, Dan Pittenger

All Master's Theses

Glaciers and seasonal snowpack in Washington State have undergone significant decline over the past 50 years. While warming global temperatures are widely recognized as the cause of glacial decline, the deposition of black carbon (BC) can also contribute to increased melt. BC, commonly referred to as soot, is produced by the incomplete combustion of fossil and biofuels. These particles are subject to atmospheric transport and are deposited on snow by wind and precipitation events. When BC is deposited, it lowers the albedo of the glacial surface resulting in increased energy absorption and melt. We used a 158 m long ice …

Greenland Subglacial Drainage Evolution Regulated By Weakly Connected Regions Of The Bed, Matthew J. Hoffman, Lauren C. Andrews, Stephen A. Price, Ginny A. Catania, Thomas A. Neumann, Martin P. Luthi, Jason Gulley, Claudia Ryser, Robert L. Hawley, Blaine Morris

Dartmouth Scholarship

Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of …

Teleconnections In Steam: Antarctic Field-Camp Art, Craig Stevens, Gabby O'Connor

The Transdisciplinary STEAM+ Journal

We describe a component of a multi-element STEAM collaboration looking to explore ideas around the life cycle of Antarctic sea ice. One of the intermediate phases of the work involved the scientist deploying partially pre-made art components. Results were modulated by weather and operational constraints and generated a sequence of images and recordings as well as greater understanding of the creative collaboration process.

Glaciers In Equilibrium, Mcmurdo Dry Valleys, Antarctica, Andrew G. Fountain, Hassan J. Basagic, Spencer Niebuhr

Geology Faculty Publications and Presentations

The McMurdo Dry Valleys are a cold, dry polar desert and the alpine glaciers therein exhibit small annual and seasonal mass balances, often

Modeling The Thickness Of Perennial Ice Covers On Stratified Lakes Of The Taylor Valley, Antarctica, Maciej K. Obryk, Peter T. Doran, Jared A. Hicks, Christopher P. Mckay, John Charles Priscu

Geology Faculty Publications and Presentations

A 1-D ice cover model was developed to predict and constrain drivers of long-term ice thick-ness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface ra-diative heat fluxes and heat fluxes from the underlying water column. The model successfully reproduced 16 a (between 1996 and 2012) of ice thickness changes for the west lobe of Lake Bonney (average ice thickness = 3.53 m) and Lake Fryxell (average ice thickness = 4.22 m). Long-term ice thick-ness trends require coupling with the thermal structure of the water column. The heat stored within the temperature maximum of …

Montauk Point, An Essential Field Experience For Students In The New York City Area, Stanley Schleifer, Nazrul I. Khandaker, Keshaw Narine

Publications and Research

Except for a thin strip of Proterozoic and Paleozoic metamorphic and igneous rock along its very western edge and an outcropping of coastal plain deposits along its northwestern edge, the surface of Long Island is immediately underlain by unconsolidated deposits consisting of moraines of glacial till, outwash plains of stratified drift, and beach and dune complex formed by wave action. Two very prominent features of the island are the Harbor Hill Moraine, which marks the southernmost extent of the last major advance of continental glacier ice in the New York area during the Pleistocene and the Ronkonkoma Moraine, which marks …

Surficial Geology Of York College Campus (Queens) And Montauk Point (Long Island): An Open Access To Geoscience Education, Nazrul I. Khandaker, Stanley Schleifer, Krishna Mahabir, Erik Menjivar, Ality Aghedo, Dennis Baidoo, Tenzin Choeying, Vanessa Erwin, Jonathan Xavier, Laboni Molla, Akeed Alrubay

Publications and Research

To evaluate compositional and textural differences among the samples collected from York College (YC) campus (Queens), Montauk Point (MP) and Hither Hills (HH), Long Island, emphasis is given to the general geologic setting, overall grain size distribution, and relative abundances of light and heavy mineral assemblages. Geologic setting encompasses outwash plains (York College), fluvioglacial and glacial (Montauk Point) and beach and dune complex (Hither Hills). YC samples were collected from depth ranging 40 cm to 250 cm and are mostly an assortment of medium to coarse sand, granule to cobble sized, minor silt, and clay. Presence of low angle cross …

Tibetan Plateau Geladaindong Black Carbon Ice Core Record (1843–1982): Recent Increases Due To Higher Emissions And Lower Snow Accumulation, Matthew Jenkins, Susan Kaspari, Kang Shi-Chang, Bjorn Grigholm, Paul A. Mayewski

Student Published Works

Black carbon (BC) deposited on snow and glacier surfaces can reduce albedo and lead to accelerated melt. An ice core recovered from Guoqu glacier on Mt. Geladaindong and analyzed using a Single Particle Soot Photometer (SP2) provides the first long-term (1843–1982) record of BC from the central Tibetan Plateau. Post 1940 the record is characterized by an increased occurrence of years with above average BC, and the highest BC values of the record. The BC increase in recent decades is likely caused by a combination of increased emissions from regional BC sources, and a reduction in snow accumulation. Guoqu glacier …

Greenland Annual Accumulation Along The Egig Line, 1959–2004, From Asiras Airborne Radar And Neutron-Probe Density Measurements, Thomas B. Overly, Robert L. Hawley, Veit Helm, Elizabeth M. Morris, Rohan N. Chaudhary

Dartmouth Scholarship

We report annual snow accumulation rates from 1959 to 2004 along a 250 km segment of the Expéditions Glaciologiques Internationales au Groenland (EGIG) line across central Greenland using Airborne SAR/Interferometric Radar Altimeter System (ASIRAS) radar layers and high resolution neutron-probe (NP) density profiles. ASIRAS-NP-derived accumulation rates are not statistically different (95 % confidence interval) from in situ EGIG accumulation measurements from 1985 to 2004. ASIRAS-NP-derived accumulation increases by 20 % below 3000 m elevation, and increases by 13 % above 3000 m elevation for the period 1995 to 2004 compared to 1985 to 1994. Three Regional Climate Models (PolarMM5, RACMO2.3, …

Linking In-Situ Data With Remote Sensing To Analyze Tropical Glacier Stability And Retreat In The Cordillera Blanca, Peru, Chandler H. Santos

Masters Theses & Specialist Projects

Glaciers are a major source of freshwater around the world, but they are melting at an increased rate due to atmospheric warming resulting from anthropogenic climate change. In addition to temperature increases, light-absorbing particulates on glaciers also are contributing to glacial melt. This research examines how black carbon, released into the air through partial combustion of biofuels, is affecting the surface albedo of glaciers. I also delineate possible sources of black carbon in the Cordillera Blanca region of Peru. Ground data were collected each year from 2011 to 2013 during the local dry season. Effective black carbon (eBC) values were …