Open Access. Powered by Scholars. Published by Universities.®

Glaciology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 91 - 120 of 452

Full-Text Articles in Glaciology

Trace Metals And The Environment: Studying The Behaviour Of Iceland’S Glacially Sourced Trace Metals, Owen Bailey Oct 2020

Trace Metals And The Environment: Studying The Behaviour Of Iceland’S Glacially Sourced Trace Metals, Owen Bailey

Independent Study Project (ISP) Collection

Trace metal contamination in marine ecosystems is a problem for every trophic level, from zooplankton up to humans. The mobility and uptake availability of these metals depend on such environmental parameters as salinity, temperature, and pH, among others. To explore the effects of varying parameters on dissolved metal behaviour, I studied the Jökulsárlón glacial lagoon, into which the Breidamerkurjökull glacier deposits trace metals from volcanic ash through glacial melt. In this study I develop and follow a sampling procedure to analyze trace metal concentrations in the lagoon, while additionally discussing the behaviour and impact of trace metals, focusing on cadmium, …

Go to article

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 Sep 2020

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

All Materials

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.

Go to article

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 Sep 2020

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

OES 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 conditions. Unexpectedly, the …

Go to article

The Post-Wildfire Impact Of Burn Severity And Age On Black Carbon Snow Deposition And Implications For Snow Water Resources, Cascade Range, Washington, Ted M. Uecker, Susan D. Kaspari, Keith N. Musselman, S. Mckenzie Skiles Aug 2020

The Post-Wildfire Impact Of Burn Severity And Age On Black Carbon Snow Deposition And Implications For Snow Water Resources, Cascade Range, Washington, Ted M. Uecker, Susan D. Kaspari, Keith N. Musselman, S. Mckenzie Skiles

Geological Sciences Faculty Scholarship

Wildfires in the snow zone affect ablation by removing forest canopy, which enhances surface solar irradiance, and depositing light absorbing particles [LAPs, such as black carbon (BC)] on the snowpack, reducing snow albedo. How variations in BC deposition affects post-wildfire snowmelt timing is poorly known and highly relevant to water resources. We present a field-based analysis of BC variability across five sites of varying burn age and burn severity in the Cascade Range, Washington State, United States. Single particle soot photometer (SP2) analyses of BC snow concentrations were used to assess the impact of BC on snow albedo, and radiative …

Go to article

Automated Terminus Detection For Greenland's Peripheral Marine-Terminating Glaciers, Julia Liu Aug 2020

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 …

Go to article

Quantitative Analyses Of Cirques On The Faroe Islands: Evidence For Time Transgressive Glacier Occupation, Keyleigh N. Wallick, Sarah M. Principato Jul 2020

Quantitative Analyses Of Cirques On The Faroe Islands: Evidence For Time Transgressive Glacier Occupation, Keyleigh N. Wallick, Sarah M. Principato

Student Publications

This study presents the first analysis of ice‐free cirques on the Faroe Islands using a Geographical Information System (GIS) and the Automated Cirque Metric Extraction (ACME) tool. The length, width, area, circularity, mean aspect, mean slope, and elevation range, minimum, and maximum were calculated using ACME. Cirque distance to coastline was measured using ArcGIS. A total of 116 cirques were identified. Mean cirque length is 950 m and mean cirque width is 890 m. Average cirque area is 0.8 km2 and mean elevation is 386 m a.s.l. The modal orientation of the aspect of cirques is north‐northeast, with a vector …

Go to article

Evaluation Of Iceberg Calving Models Against Observations From Greenland Outlet Glaciers, Tristan Amaral, Timothy C. Bartholomaus, Ellyn M. Enderlin Jun 2020

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 across all …

Go to article

Analysis Of Antarctic Peninsula Glacier Frontal Ablation Rates With Respect To Iceberg Melt-Inferred Variability In Ocean Conditions, M. C. Dryak, E. M. Enderlin Jun 2020

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 …

Go to article

Applications Of Digital Remote Sensing To Quantify Glacier Change In Glacier And Mount Rainier National Parks, Brianna Clark May 2020

Applications Of Digital Remote Sensing To Quantify Glacier Change In Glacier And Mount Rainier National Parks, Brianna Clark

Electronic Theses and Dissertations

Digital remote sensing and geographic information systems were employed in performing area and volume calculations on glacial landscapes. Characteristics of glaciers from two geographic regions, the Intermountain Region (between the Rocky Mountain and Cascade Ranges) and the Pacific Northwest, were estimated for the years 1985, 2000, and 2015. Glacier National Park was studied for the Intermountain Region whereas Mount Rainier National Park was representative of the glaciers in the Pacific Northwest. Within the thirty year period of the study, the glaciers in Glacier National Park decreased in area by 27.5 percent while those on Mount Rainier only decreased by 5.7 …

Go to article

Climate From The Mcmurdo Dry Valleys, Antarctica, 1986–2017: Surface Air Temperature Trends And Redefined Summer Season, Maciej K. Obryk, Peter T. Doran, Andrew G. Fountain, M. Myers, Christopher P. Mckay May 2020

Climate From The Mcmurdo Dry Valleys, Antarctica, 1986–2017: Surface Air Temperature Trends And Redefined Summer Season, Maciej K. Obryk, Peter T. Doran, Andrew G. Fountain, M. Myers, Christopher P. Mckay

Geology Faculty Publications and Presentations

The weather of the McMurdo Dry Valleys, Antarctica, the largest ice‐free region of the Antarctica, has been continuously monitored since 1985 with currently 14 operational meteorological stations distributed throughout the valleys. Because climate is based on a 30‐year record of weather, this is the first study to truly define the contemporary climate of the McMurdo Dry Valleys. Mean air temperature and solar radiation based on all stations were −20°C and 102 Wm−2, respectively. Depending on the site location, the mean annual air temperatures on the valleys floors ranged between −15°C and −30°C, and mean annual solar radiation varied …

Go to article

Climate Change Effects On Volcanoes In The Tropics: A Review Of The Deglaciation Of Antisana And Its Effects On Subsequent Water Streams And Rivers Over 20 Years, Callie C. Rominger Apr 2020

Climate Change Effects On Volcanoes In The Tropics: A Review Of The Deglaciation Of Antisana And Its Effects On Subsequent Water Streams And Rivers Over 20 Years, Callie C. Rominger

Independent Study Project (ISP) Collection

Located in the Northern end of Ecuador lies the stunning glacier of Antisana which attracts many tourists and whose runoff provides a significant amount of water supply for Quito. Climate change is posing threats to many ecosystems world wide but will have a more substantial impact on the volcanoes in the tropics because they do not have a seasonally altered climate. Small changes in the air temperature can have larger impacts on these areas that are adapted to constant temperatures with seasonal precipitation changes. Climate change, in recent years, had caused an increase in the glacial retreat of the Antisana …

Go to article

La Relación Entre Cambio Climático Y Migración En Los Andes De Perú: Los Q’Ero, Taquile Y La Cordillera Blanca, Sam Hosmer-Quint Apr 2020

La Relación Entre Cambio Climático Y Migración En Los Andes De Perú: Los Q’Ero, Taquile Y La Cordillera Blanca, Sam Hosmer-Quint

Independent Study Project (ISP) Collection

El cambio climático es uno de los problemas más grandes en el mundo. Los afectos de los cambios serán más graves para las personas más pobres y vulnerables. Perú es reconocido como uno de los países más vulnerables en el mundo, a causa de la presencia de glaciares tropicales, las cual son muy vulnerables a la desglaciación. Los efectos de cambio climático incluyen, entre otras cosas; el cambio de la temporada de lluvias y sequias, un aumento de la temperatura ambiental, inundaciones y tormentas severas. Todos estos factores hacen del cambio climático un riesgo para mucha gente y además, tiene …

Go to article

Twentieth Century Black Carbon And Dust Deposition On South Cascade Glacier, Washington State, Usa, As Reconstructed From A 158‐M‐Long Ice Core, Susan D. Kaspari, Dan Pittenger, T. M. Jenk, U. Morgenstern, M. Schwikowski, N. Buenning, L. Stott Feb 2020

Twentieth Century Black Carbon And Dust Deposition On South Cascade Glacier, Washington State, Usa, As Reconstructed From A 158‐M‐Long Ice Core, Susan D. Kaspari, Dan Pittenger, T. M. Jenk, U. Morgenstern, M. Schwikowski, N. Buenning, L. Stott

All Faculty Scholarship for the College of the Sciences

Light absorbing particles (LAPs) include black carbon (BC) and mineral dust and are of interest due to their positive radiative forcing and contribution to albedo reductions and snow and glacier melt. This study documents historic BC and dust deposition as well as their effect on albedo on South Cascade Glacier (SCG) in Washington State (USA) through the analysis of a 158‐m (139.5‐m water equivalent [w.e.]) ice core extracted in 1994 and spanning the period 1840–1991. Peak BC deposition occurred between 1940 and 1960, when median BC concentrations were 16 times higher than background, likely dominated by domestic coal and forest …

Go to article

Future Evolution Of Greenland's Marine-Terminating Outlet Glaciers, G. A. Catania, L. A. Stearns, T. A. Moon, E. M. Enderlin, R. H. Jackson Feb 2020

Future Evolution Of Greenland's Marine-Terminating Outlet Glaciers, G. A. Catania, L. A. Stearns, T. A. Moon, E. M. Enderlin, R. H. Jackson

Geosciences Faculty Publications and Presentations

Mass loss from the Greenland ice sheet (GrIS) has increased over the last two decades in response to changes in global climate, motivating the scientific community to question how the GrIS will contribute to sea-level rise on timescales that are relevant to coastal communities. Observations also indicate that the impact of a melting GrIS extends beyond sea-level rise, including changes to ocean properties and circulation, nutrient and sediment cycling, and ecosystem function. Unfortunately, despite the rapid growth of interest in GrIS mass loss and its impacts, we still lack the ability to confidently predict the rate of future mass loss …

Go to article

Esd Ideas: Why Are Glaciations Slower Than Deglaciations?, Christine J. Ramadhin, Chuixiang Yi Jan 2020

Esd Ideas: Why Are Glaciations Slower Than Deglaciations?, Christine J. Ramadhin, Chuixiang Yi

Publications and Research

The Earth’s climate during the Quaternary is dominated by short warm interglacials and longer cold glaciations paced by external forcings such as changes in insolation. Although not observed in the solar radiation changes, the time series of the cycles display asymmetry since transitions to full glacial conditions are slower than the termination of glaciations. Here an idea is proposed for the slower transition by identifying and describing two negative sea ice feedbacks dominant during the glaciation process that could serve as a control on the intermediate stage and decrease the pace of the process.

Go to article

Glacial Earthquakes And Precursory Seismicity Associated With Thwaites Glacier Calving, J. Paul Winberry, Audrey D. Huerta, Sridhar Anandakrishnan, Richhard C. Aster, Andrew A. Nyblade, Douglas A. Wiens Jan 2020

Glacial Earthquakes And Precursory Seismicity Associated With Thwaites Glacier Calving, J. Paul Winberry, Audrey D. Huerta, Sridhar Anandakrishnan, Richhard C. Aster, Andrew A. Nyblade, Douglas A. Wiens

All Faculty Scholarship for the College of the Sciences

We observe two (~MS 3) long‐period (10–30 s) seismic events that originate from the terminus of Thwaites Glacier, Antarctica. Serendipitous acquisition of satellite images confirm that the seismic events were glacial earthquakes generated during the capsizing of icebergs. The glacial earthquakes were preceded by 6 days of discrete high‐frequency seismic events that can be observed at distances exceeding 250 km. The high‐frequency seismicity displays an increasing rate of occurrence, culminating in several hours of sustained tremor coeval with the long‐period events. A series of satellite images collected during this precursory time period show that the high‐frequency events and …

Go to article

Chronology Of Advance And Recession Dynamics Of The Southern Green Bay Lobe Of The Laurentide Ice Sheet, South-Central Wisconsin, Usa, Eric C. Carson, John W. Attig, J. Elmo Rawling Iii, Paul R. Hanson, Stefanie E. Dodge Jan 2020

Chronology Of Advance And Recession Dynamics Of The Southern Green Bay Lobe Of The Laurentide Ice Sheet, South-Central Wisconsin, Usa, Eric C. Carson, John W. Attig, J. Elmo Rawling Iii, Paul R. Hanson, Stefanie E. Dodge

School of Natural Resources: Faculty Publications

We used a combination of accelerator mass spectrometry (AMS) radiocarbon dating, optically stimulated luminescence (OSL) age estimates, and stratigraphic data from cores collected along the southern margin of the Green Bay Lobe (GBL) of the Laurentide Ice Sheet to provide new information on the timing and dynamics of the end of advance of the GBL and the dynamics of the ice sheet while very near its maximum position. Coring at multiple sites along the margin of the GBL indicate that ice had reached a stable position near its maximum extent by 24.7 ka; that ice advanced several kilometers to the …

Go to article

Rock Glacier Development In The San Juan Mountains, Brandon K. Bailey Jan 2020

Rock Glacier Development In The San Juan Mountains, Brandon K. Bailey

Electronic Theses and Dissertations

Rock glaciers are common landform features found in deglaciated alpine areas. They are commonly used in the study of climatic changes throughout the Holocene and the reconstruction of neoglacial chronologies. For this research, Schmidt hammer rebound values, weathering rind thicknesses, and the length of lichen thalli diameters found on rock glacier surfaces are used to investigate their effectiveness as field-based relative age determination techniques. Additionally, the ability to identify periods of neoglacial activity using these methods is assessed in two neighboring cirque basins in the San Juan Mountains of Colorado. 41 field sites across three rock glaciers are established with …

Go to article

The Seasonal Evolution Of Albedo Across Glaciers And The Surrounding Landscape Of Taylor Valley, Antarctica, Anna Bergstrom, Michael N. Gooseff, Peter T. Doran, Julian M. Cross Jan 2020

The Seasonal Evolution Of Albedo Across Glaciers And The Surrounding Landscape Of Taylor Valley, Antarctica, Anna Bergstrom, Michael N. Gooseff, Peter T. Doran, Julian M. Cross

Geology Faculty Publications and Presentations

The McMurdo Dry Valleys (MDVs) of Antarctica are a polar desert ecosystem consisting of alpine glaciers, ice-covered lakes, streams, and expanses of vegetation-free rocky soil. Because average summer temperatures are close to 0 Cel., the MDV ecosystem in general, and glacier melt dynamics in particular, are both closely linked to the energy balance. A slight increase in incoming radiation or change in albedo can have large effects on the timing and volume of meltwater. However, the seasonal evolution or spatial variability of albedo in the valleys has yet to fully characterized. In this study, we aim to understand the drivers …

Go to article

Climate And Surging Of Donjek Glacier, Yukon, Canada, Ellyn M. Enderlin Jan 2020

Climate And Surging Of Donjek Glacier, Yukon, Canada, Ellyn M. Enderlin

Geosciences Faculty Publications and Presentations

Links between climate and glacier surges are poorly understood but are required to enable prediction of surges and mitigation of associated hazards. Here, we investigate the role of snow accumulation, rain, and temperature on surge periodicity, area changes, and timing of surge initiation since the 1930s at Donjek Glacier, Yukon, Canada. Snow accumulation measured in three ice cores collected at Eclipse Icefield indicates that a cumulative accumulation of 15.5 ± 1.46 or 16.6 ± 2.0 m w.e. occurred in the ten to twelve years between each of its last eight surges, depending on ice motion spatiotemporal offset corrections. Although we …

Go to article

Geochemical Flux Analysis Of Glacial River Runoff For Sólheimajökull, Iceland, Jessica Garrison Jan 2020

Geochemical Flux Analysis Of Glacial River Runoff For Sólheimajökull, Iceland, Jessica Garrison

Mahurin Honors College Capstone Experience/Thesis Projects

Geochemical fluxes in aqueous studies are an essential component of research to understand weathering and changes in a hydrologic system. These data can indicate any discrepancies, outliers, or gradual changes in a water environment to gain information on pollutants, carbon cycles, biological input, etc. Glacial melt is the majority of the surface water present throughout the country. The melting amount is increasing with the temperatures, which can be monitored by the changes in geochemical flux during increased discharge in glacial rivers. A high-resolution data set of Sόlheimajökull Glacier in Iceland was used to determine how changing climatic conditions for the …

Go to article

Sampling The Local Fare: Fishes At The Sam Israel House Pit (45gr76), Soap Lake, Washington, Adam Fruge Jan 2020

Sampling The Local Fare: Fishes At The Sam Israel House Pit (45gr76), Soap Lake, Washington, Adam Fruge

All Master's Theses

The Sam Israel site is a precontact archaeological complex with numerous fish bones at the north end of Soap Lake, Washington. Excavated in 1976, the fish remains recovered from there were never fully analyzed prior to this research. Since this inland Columbia Plateau site had thousands of fish bones, it contained untapped potential for our understanding of ancient local fish procurement. As such, I conducted a detailed analysis of 2,862 fish bone specimens from the Sam Israel House Pit locus to: study a larger sample of fish bones in greater detail than was done before; compare the distribution of fishes …

Go to article

Improving Aquifer Characterization Through Integration Of Airborne Electromagnetics (Aem) And Well Hydrographs, Jacqueline Polashek Dec 2019

Improving Aquifer Characterization Through Integration Of Airborne Electromagnetics (Aem) And Well Hydrographs, Jacqueline Polashek

School of Natural Resources: Dissertations, Theses, and Student Research

The objective of this study is to evaluate methods of hydrostratigraphic modeling using geophysics and well hydrographs at the eastern edge of the High Plains aquifer (HPA) in Platte and Colfax counties within Nebraska, USA. The HPA is very heterogeneous in the study area, being hosted by architecturally complex glacial sediments and having many irregular hydraulic boundaries. Further, the HPA exhibits local variations between unconfined and confined conditions. Pumping in such bounded aquifers can be unsustainable because of cost increases and lost agricultural productivity. Moreover, the large drawdowns typical of confined aquifers can contribute to well interference during heavy pumping. …

Go to article

An Evaluation Of Soils On Sólheimajökull Glacier Foreland: Using Invertebrates And Decomposition As Bio-Indicators Of Soil Quality, Carolyn Weisman Oct 2019

An Evaluation Of Soils On Sólheimajökull Glacier Foreland: Using Invertebrates And Decomposition As Bio-Indicators Of Soil Quality, Carolyn Weisman

Independent Study Project (ISP) Collection

Anthropogenic climate change has led to the retreat of glaciers globally. As glaciers melt, they expose the underlying land- termed the glacier foreland. These forelands provide a natural laboratory for studying ecological succession after a massive disturbance, which is in this case glaciation. In this study, soil invertebrates and decomposition are used as bio-indicators of the soil quality in the foreland of Sólheimajökull Outlet Glacier. Soil cores were collected from five sites (A-E) located 300m apart moving away from the glacier terminus. The abundance of each observed invertebrate taxa and the dissolved oxygen (DO) levels were taken for 30 soil …

Go to article

A Collection Of On-Ice Arctic Measurements 1879-2013, Ryan Avila Sep 2019

A Collection Of On-Ice Arctic Measurements 1879-2013, Ryan Avila

STAR Program Research Presentations

Ice thickness measurements have been taken in the arctic through a variety of means for a long time in order to better understand the long-term changes to sea ice. This project is focused on measurements made directly on the ice by using an auger or electromagnetic sounding which have both been shown to be highly accurate compared to other observational methods. Our first goal is to create and update an archive of sea ice data that collects smaller separated data sets in one easy to access location for other researchers to use. Our second goal is to use this data …

Go to article

Seismic Observations Of Crevasse Growth Following Rain-Induced Glacier Acceleration, Haupapa/Tasman Glacier, New Zealand, Samuel Taylor-Offord, Huw Horgan, John Townend, J. Paul Winberry May 2019

Seismic Observations Of Crevasse Growth Following Rain-Induced Glacier Acceleration, Haupapa/Tasman Glacier, New Zealand, Samuel Taylor-Offord, Huw Horgan, John Townend, J. Paul Winberry

All Faculty Scholarship for the College of the Sciences

Changing rates of water input can affect both the flow of glaciers and ice sheets and their propensity to crevasse. Here we examine geodetic and seismic observations during two substantial (10–18-times background velocity) rain-induced glacier accelerations at Haupapa/Tasman Glacier, New Zealand. Changes in rain rate result in glacier acceleration and associated uplift, which propagate down-glacier. This pattern of acceleration results in a change to the strain rate field, which correlates with an order of magnitude increase in the apparent seismicity rate and an overall down-glacier migration in located seismicity. After each acceleration event the apparent seismicity rate decreases to below …

Go to article

Tidal And Spatial Variability Of Flow Speed And Seismicity Near The Grounding Zone Of Beardmore Glacier, Antarctica, Jade Cooley, J. Paul Winberry, Michelle Koutnik, Howard Conway May 2019

Tidal And Spatial Variability Of Flow Speed And Seismicity Near The Grounding Zone Of Beardmore Glacier, Antarctica, Jade Cooley, J. Paul Winberry, Michelle Koutnik, Howard Conway

All Faculty Scholarship for the College of the Sciences

GPS measurements of tidal modulation of ice flow and seismicity within the grounding zone of Beardmore Glacier show that tidally induced fluctuations of horizontal flow are largest near the grounding line and decrease downstream. Seismic activity is continuous, but peaks occur on falling and rising tides. Beamforming methods reveal that most seismic events originate from two distinct locations, one on the grid-north side of the grounding zone, and one on the grid-south side. The broad pattern of deformation generated as Beardmore Glacier merges with the Ross Ice Shelf results in net extension along the grid-north side of the grounding zone …

Go to article

Engaging The Greater Lafayette Community In A Journey Through The Earth Sciences: Purdue’S Eaps Earth Science Passport Day Event, Dara Laczniak, Bradley Garczynski Mar 2019

Engaging The Greater Lafayette Community In A Journey Through The Earth Sciences: Purdue’S Eaps Earth Science Passport Day Event, Dara Laczniak, Bradley Garczynski

Engagement & Service-Learning Summit

No abstract provided.

Go to article

Seismic Tremor Reveals Spatial Organization And Temporal Changes Of Subglacial Water System, Margot E. Vore, Timothy C. Bartholomaus, J. Paul Winberry, Jacob I. Walter, Jason M. Amundson Feb 2019

Seismic Tremor Reveals Spatial Organization And Temporal Changes Of Subglacial Water System, Margot E. Vore, Timothy C. Bartholomaus, J. Paul Winberry, Jacob I. Walter, Jason M. Amundson

All Faculty Scholarship for the College of the Sciences

Subglacial water flow impacts glacier dynamics and shapes the subglacial environment. However, due to the challenges of observing glacier beds, the spatial organization of subglacial water systems and the time scales of conduit evolution and migration are largely unknown. To address these questions, we analyze 1.5‐ to 10‐Hz seismic tremor that we associate with subglacial water flow, hat is, glaciohydraulic tremor, at Taku Glacier, Alaska, throughout the 2016 melt season. We use frequency‐dependent polarization analysis to estimate glaciohydraulic tremor propagation direction (related to the subglacial conduit location) and a degree day melt model to monitor variations in melt‐water input. We …

Go to article

Comparison Of Microbial Communities In The Sediments And Water Columns Of Frozen Cryoconite Holes In The Mcmurdo Dry Valleys, Antarctica, Pacifica Sommers, John L. Darcy, Dorota L. Porazinska, Eli M. S. Gendron, Andrew G. Fountain, Felix Jacob Zamora, Kim Vincent, Kaelin M. Cawley, Adam J. Solon, Lara Vimercati, Jenna Ryder, Steven K. Schmidt Feb 2019

Comparison Of Microbial Communities In The Sediments And Water Columns Of Frozen Cryoconite Holes In The Mcmurdo Dry Valleys, Antarctica, Pacifica Sommers, John L. Darcy, Dorota L. Porazinska, Eli M. S. Gendron, Andrew G. Fountain, Felix Jacob Zamora, Kim Vincent, Kaelin M. Cawley, Adam J. Solon, Lara Vimercati, Jenna Ryder, Steven K. Schmidt

Geology Faculty Publications and Presentations

Although cryoconite holes, sediment-filled melt holes on glacier surfaces, appear small and homogenous, their microbial inhabitants may be spatially partitioned. This partitioning could be particularly important for maintaining biodiversity in holes that remain isolated for many years, such as in Antarctica. We hypothesized that cryoconite holes with greater species richness and biomass should exhibit greater partitioning between the sediments and water, promoting greater biodiversity through spatial niche partitioning. We tested this hypothesis by sampling frozen cryoconite holes along a gradient of biomass and biodiversity in the Taylor Valley, Antarctica, where ice-lidded cryoconite holes are a ubiquitous feature of glaciers. We …

Go to article

First Prev Next Last