Glaciology Commons^™

Contrasting Patterns In Surface Ice Velocity Of Glaciers In The Nepal Himalayas, Katherine Strattman

Von Braun Symposium Student Posters

No abstract provided.

A Sub-Millennial Sediment Record Of Ice-Stream Retreat And Meltwater Storage In The Baltic Ice Lake During The Bølling-Allerød Interstadial, April Lynn Kelly, Sandra Passchier

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The rapid retreat of the Baltic Ice Stream and the development of the Baltic Ice Lake is assessed using data from sediment cores retrieved from three sub-basins in the southern Baltic Sea. Hydraulic piston coring by the International Ocean Discovery Program (IODP) recovered for the first time intact glacial lake sequences overlying diamictons and other ice-contact deposits at Sites M0063, M0064 and M0065. Based on the particle size and bulk sediment chemical composition the glacial lake sediments were subdivided into a proximal and a distal varve sequence. The origin of a dark, lithologically distinct horizon between the proximal and distal …

The 2015 Landslide And Tsunami In Taan Fiord, Alaska, Bretwood Higman, Breanyn Macinnes, Colin Bloom

All Faculty Scholarship for the College of the Sciences

Glacial retreat in recent decades has exposed unstable slopes and allowed deep water to extend beneath some of those slopes. Slope failure at the terminus of Tyndall Glacier on 17 October 2015 sent 180 million tons of rock into Taan Fiord, Alaska. The resulting tsunami reached elevations as high as 193 m, one of the highest tsunami runups ever documented worldwide. Precursory deformation began decades before failure, and the event left a distinct sedimentary record, showing that geologic evidence can help understand past occurrences of similar events, and might provide forewarning. The event was detected within hours through automated seismological …

Decadal Topographic Change In The Mcmurdo Dry Valleys Of Antarctica: Thermokarst Subsidence, Glacier Thinning, And Transfer Of Water Storage From The Cryosphere To The Hydrosphere, J. S. Levy, Andrew G. Fountain, M. K. Obryk, J. Telling, Craig Glennie, M. Gooseff, David J. Van Horn

Geology Faculty Publications and Presentations

Recent local-scale observations of glaciers, streams, and soil surfaces in the McMurdo Dry Valleys of Antarctica (MDV) have documented evidence for rapid ice loss, glacial thinning, and ground surface subsidence associated with melting of ground ice. To evaluate the extent,magnitude, and location of decadal-scale landscape change in the MDV, we collected airborne lidar elevation data in 2014–2015 and compared these data to a 2001–2002 airborne lidar campaign. This regional assessment of elevation change spans the recent acceleration of warming and melting observed by long-term meteorological and ecosystem response experiments, allowing us to assess the response of MDV surfaces to warming …

Quantifying The Effects Of Wind Regimes And Temperature On Surface Melt Over The Antarctic Peninsula (1982–2017) Through Modeling, Remote Sensing And In-Situ Data, Rajashree Datta

Dissertations, Theses, and Capstone Projects

Surface melting over the Antarctic Peninsula (AP) plays a crucial role for the stability of ice shelves and dynamics of grounded ice, hence modulating the mass balance in a region of the world which is particularly sensitive to increasing surface temperatures. Understanding the processes that drive melting using surface energy and mass balance models is fundamental to improving estimates of current and future surface melting and associated sea level rise through ice-shelf collapse. This is even more important in view of the specific challenges presented by how circulation patterns over the topographically-complex Antarctic Peninsula, especially foehn winds, impact surface melt. …

The Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, Arya Bina

Electronic Thesis and Dissertation Repository

Currently, Mars appears to be in a ‘frozen’ and ‘dry’ state, with the clear majority of the planet’s surface maintaining year-round sub-zero temperatures. However, the discovery of features consistent with landforms found in periglacial environments on Earth, suggests a climate history for Mars that may have involved freeze and thaw cycles. Such landforms include hummocky, polygonised, scalloped, and pitted terrains, as well as ice-rich deposits and gullies, along the mid- to high-latitude bands, typically with no lower than 20o N/S. The detection of near-surface and surface ice via the Phoenix lander, excavation of ice via recent impact cratering activity as …

Rock Glaciers Of The Contiguous United States: Spatial Distribution, Cryospheric Context, And Riparian Vegetation, Gunnar Forrest Johnson

Dissertations and Theses

Continental-scale inventories of glaciers are available, but no analogous rock glacier inventories exist. We present the Portland State University Rock Glacier Inventory (n = 10,343) for the contiguous United States, then compare it to an existing inventory of contiguous United States glaciers (n = 853), identifying geographic and climatic factors affecting the spatial distributions observed. At least one rock glacier is identified in each of the 11 westernmost states, but nearly 90% are found in just five; Colorado (n = 3889), Idaho (n = 1723), Montana (n = 1780), Utah (n = 834), and Wyoming (n = 849). Glaciers are …

Geomorphology Of Icy Debris Fans: Delivery Of Ice And Sediment To Valley Glaciers Decoupled From Icecaps, R. Craig Kochel, Jeffrey M. Trop, Robert W. Jacob

Faculty Journal Articles

The pace and volume of mass flow processes contributing ice and sediment to icy debris fans (IDFs) were documented at sites in Alaska and New Zealand by integrating field observations, drone and time-lapse imagery, ground penetrating radar, and terrestrial laser scanning. Largely unstudied, IDFs are supraglacial landforms at the mouths of bedrock catchments between valley glaciers and icecaps. Time-lapse imagery recorded 300–2300 events reaching 15 fans during intervals from nine months to two years. Field observations noted hundreds of deposits trapped within catchments weekly that were later remobilized onto fans. Deposits were mapped on images taken three to four times …

Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier

Sandra Passchier

The present study deals with heavy mineral analysis of late Early Miocene marine sediments recovered in the McMurdo Sound region (Ross Sea, Antarctica) during the ANDRILL— SMS Project in 2007. The main objective is to investigate how heavy mineral assemblages reflect different source rocks and hence different provenance areas. These data contribute to a better understanding of East Antarctica ice dynamics in the Ross Sea sector during the Early Miocene (17.6–20.2 Ma), a time of long-term global warming and sea level rise. The AND-2A drill core recovered several stratigraphic intervals that span from Early Miocene to Pleistocene and it collected …

The Impact Of Ground-Based Glaciogenic Seeding On A Shallow Stratiform Cloud Over The Sierra Madre In Wyoming: A Multi-Sensor Study Of The 3 March 2012 Case, Binod Pokharel, Bart Geerts, Xiaoqin Jing

Plants, Soils and Climate Student Research

A case study is presented of the impact of ground-based glaciogenic seeding on a shallow, lightly precipitating orographic storm with abundant supercooled cloud droplets, but few ice particles. The storm was observed on 3 March 2012 as part of the AgI (silver iodide) Seeding Cloud Impact Investigating (ASCII) experiment in Wyoming. The cloud base temperature was about -9°C, and cloud tops were at about -16°C. The high concentration of small droplets and low ice particle concentration lead to natural snow growth, mainly by vapor diffusion. The question addressed here is whether the injection of ice nucleating particles (AgI) enhanced snow …

Joint Geodetic And Seismic Analysis Of Englacial And Subglacial Hydraulic Effects On Surface Crevassing Near A Seasonal, Glacier-Dammed Lake On Gornergletscher, Switzerland, Louis Stephen Garcia

LSU Master's Theses

Glacial outburst floods are difficult to predict and threaten human life. These events are characterized by rapid draining of glacier-dammed lakes via the sub/englacial hydraulic network to the proglacial stream. The glacier-dammed lake on Gornergletscher in Switzerland, which fills and drains each summer, provides an opportunity to study this hazard. For three drainages (2004, 2006, and 2007), icequakes (IQ) are tracked as well as on-ice GPS movement. The seasonal seismic networks had 8 – 24 three-component stations and apertures of about 300 – 400 m on the glacier surface. The seasonal GPS arrays contained 4 – 8 GPS antennae on …

Developing A Risk Assessment Protocol To Quantify Distribution And Uptake Of Persistent Organic Pollutants In Glacial Outflows, Kimberley Rain Miner

Electronic Theses and Dissertations

Pollutants released by industrialized nations between 1960 and 2004 have been transported northward through atmospheric processes and deposited into glaciated alpine ecosystems. Many of these chemicals retain their original structure and are absorbed into the biota thousands of miles away from where they were originally utilized. With a warming climate increasing the melt of alpine glaciers, these glaciers may be introducing growing amounts of toxins into the watershed. While studies have demonstrated the existence of resident pollutants within glaciated ecosystems, no one has developed a risk assessment to identify sources and quantity of risk posed by these compounds when released …

Multi-Channel Ground-Penetrating Radar For The Continuous Quantification Of Snow And Firn Density, Depth, And Accumulation, Tate Meehan

Boise State University Theses and Dissertations

A priority of ice sheet surface mass balance (SMB) prediction is ascertaining the surface density and annual snow accumulation. These forcing data are inputs for firn density models and can be used to inform remotely sensed ice sheet surface processes and to assess Regional Climate Model (RCM) skill. The Greenland Traverse for Accumulation and Climate Studies (GreenTrACS) retrieved 16 shallow firn cores and dug 42 snow pits along the Western percolation zone of the Greenland Ice Sheet (GrIS) during May and June of 2016 and 2017. I deployed and maintained a multi-channel 500 MHz ground-penetrating radar in a multi-offset configuration …

Glacial History Of The Tsagaan Gol- Potanin Glacier Valley, Altai Mountains, Mongolia, Mariah J. Radue

Electronic Theses and Dissertations

The last glacial termination (~19-11 ka) marks the end of the last ice age and the transition to modern interglacial conditions. The mechanisms that triggered deglaciation are unresolved. Various hypotheses for deglacial warming involve changes in Earth’s orbit, an 80-ppm increase in atmospheric CO­₂, a ‘bipolar seesaw’ in oceanic-heat redistribution, and shifting wind belts. Here, I present a ¹⁰Be surface-exposure chronology for a system of glacial landforms in the Tsagaan Gol-Potanin Glacier valley in the Mongolian Altai (49°N, 88°E) to determine the nature of the termination in interior Asia. Located near the center of Earth’s largest continent, …

Ice Core Records Of West Greenland Melt And Climate Forcing, H.P. Marshall, T. Meehan

CGISS Publications and Presentations

Remote sensing observations and climate models indicate that the Greenland Ice Sheet (GrIS) has been losing mass since the late 1990s, mostly due to enhanced surface melting from rising summer temperatures. However, in situ observational records of GrIS melt rates over recent decades are rare. Here we develop a record of frozen meltwater in the west GrIS percolation zone preserved in seven firn cores. Quantifying ice layer distribution as a melt feature percentage (MFP), we find significant increases in MFP in the southernmost five cores over the past 50 years to unprecedented modern levels (since 1550 CE). Annual to decadal …

Mapping And Interpreting The Glacial Geology Of Pictured Rocks National Lakeshore, Michigan, Sarah M. Vandermeer

Dissertations

Pictured Rocks National Lakeshore is among the most popular parks in Michigan, yet prior to this study, it was the only National Park that lacked a detailed surficial geology map characterizing the distribution of sediments and landforms. Additionally, much of the landscape remained unexplored. These factors prevented thorough interpretations of landscape development and evolution. This research aims to map and further explore the relationship of glacial sediments and landforms throughout Pictured Rocks to refine and expand the current understanding of glacial events that shaped this landscape.

A new, detailed (1:24,000-scale) surficial geology map of the ten 7.5-minute quadrangles that contain …

Carbon Flux And Weathering Processes In Icelandic Glacial-Fed Rivers, Allison Quiroga

Masters Theses & Specialist Projects

An investigation into the carbon dynamics and weathering processes occurring in Icelandic glacial-fed streams was conducted during the spring to summer seasonal transition in June of 2017. Four major outlet rives were sampled from the glaciers of Gígjökull, Steinsholtsjökull, Sólheimajökull, and Falljökull. Markarfljót, the major river that Gígjökull, Steinsholtsjökull, and many other glaciers drain into, was also sampled. Longitudinal sampling occurred at all sites to capture downstream trends in the hydrogeochemistry and carbon dynamics. Distinct differences in geochemistry between glacier surface meltwater, sub-glacial waters, pro-glacial lake water, and post-mixed downstream samples were evident in the data. Glacier surface streams were …

Mapping Bedrock Topography Of The Portage And Schoolcraft Nw 7.5’ Quadrangles, Kalamazoo Co. Mi, Using The Hvsr Passive Seismic Method, Benjamin B. Seiderman

Masters Theses

This study utilizes the Horizontal to Vertical Spectral Ratio (HVSR) technique to map bedrock topography in the Portage and Schoolcraft NW quadrangles, Kalamazoo Co., MI, looking for buried bedrock valleys. Glacial sediment-landform assemblages dominate the study area, due to multiple advances of the Laurentide Ice Sheet (LIS). Tunnel valleys, which are one type of buried valley, are eroded by subglacial meltwater and commonly filled with the coarser varieties of glacial outwash, making them potential aquifers. The HVSR technique measures the ratio of horizontal to vertical ground motion, excited by ambient seismic noise, resulting in a peak at the resonance frequency. …

Geologic Mapping Of The Bronson North And Bronson South 7.5-Minute Quadrangles, Branch County, Michigan, Karl John Backhaus

Masters Theses

This study contributes to a better understanding of the glacial history of southwest Michigan through detailed surficial geologic and bedrock topography mapping within the Bronson North and Bronson South Quadrangles in Branch County, Michigan. This project was supported during the summer of 2017 by the USGS EDMAP program in conjunction with the Michigan Geological Survey. Hand-auger borings, grain size analysis tests, passive seismic depth-to-bedrock measurements, and ground penetrating radar transects were collected for this study. There are 350 feet of bedrock relief from west to east across the quadrangles, including a bedrock cuesta of Mississippian Coldwater Shale. This cuesta underlies …

Topographic Control On Post-Lgm Groundings Of The West Antarctic Ice Sheet In The Whales Deep Basin, Eastern Ross Sea, Matthew Danielson

LSU Master's Theses

By the peak of the Last Glacial Maximum (LGM), the West Antarctic Ice Sheet (WAIS) had advanced to the outer continental shelf of eastern Ross Sea trough basins. During the post-LGM retreat, the WAIS paused several times within 75 km of the Whales Deep Basin (WDB) shelf edge. An overlapping stack of seven grounding zone wedges (GZWs) records the locations of these groundings. Here we used ~7500 km of seismic reflection data to map the subglacial unconformity that was eroded when WAIS was grounded at the shelf edge, i.e., prior to the deposition of the backstepping GZWs. With respect to …