Opportunities in Glacier InVEstigation
OGIVE – definition: annual bands visible in some glaciers below an ice fall
OGIVE – acronym: Opportunities in Glacier InVEstigation is an summer research program of the glaciology group at University of Washington. OGIVE provides summer research opportunities for undergraduate students at University of Washington.
The summer of 2021 was the first phase of increasing the number of undergraduate participants and graduate student mentors. Four undergraduate participants, three graduate student advisors, two faculty advisors, and many more graduate and faculty collaborators participated. Through a generous private donation, the program will be expanded in the follow years to include more undergraduate student projects, more project and mentoring development, and more field experiences. Exciting details to come.
2022 Students and Projects
Advik Eswaren: Identifying Promising Antarctic Ice Core Sites using Synthetic Records and Data Assimilation
Faculty Advisor: T.J. Fudge
Project Description: Ice cores record information about the past climate, with the two primary markers being water isotope ratios as a proxy for temperature and snow accumulation. The drilling of ice cores, however, is controlled by external constraints such as climatic setting, ice-sheet characteristics, and logistical constraints. A new ice core site ideally would have water isotope and accumulation records that improve the skill of paleoclimate reconstruction as much as possible. This project analyzes which ice core sites would do so best. We start with the Last Millennium Reanalysis (LMR), a proven climate reconstruction framework that uses the ensemble Kalman filter. We compile all existing Antarctic water isotope and accumulation data and assimilate it into LMR, with the resulting temperature anomaly reconstructions showing a highly skilled baseline that closely matches ERA5 reanalysis. We use two measures of skill: the absolute difference between LMR’s predicted anomalies and ERA5’s reanalyzed anomalies for each year, and the correlation between the two over the full time series. We then plan to create synthetic proxy records for various locations currently lacking ice cores, drawing from existing temperature reanalysis with artificially added noise. We will then assimilate these synthetic records into LMR along with the actual records, noting the skill improvement from the baseline. Finally, we will evaluate those locations that showed the greatest gain in skill according to external and logistical constraints.
Example of a LMR-predicted temperature anomaly (K), for 1998 relative to 1951-1980
Aidin Dealy: Roughness of Antarctic Ice Shelves from IceSat 2
Grad Advisor: Steph Olinger
Faculty Advisor: Brad Lipovsky
Understanding the dynamics of the Antarctic Ice Sheet (AIS) is critical as global temperatures increase and sea level continues to rise. Ice shelves stabilize the AIS, regulating the flux of grounded ice into the ocean. Ice shelf collapse destabilizes grounded glaciers, leading to rapid ice loss and an increase in the local contribution to sea level rise. Sparse observations have limited our understanding of ice shelf collapse, but newly-available satellite altimetry data offers the potential to monitor ice shelf structural integrity from space. Here, we use ICESat-2 altimetry data to characterize surface morphology of Ross and Pine Island Glacier Ice Shelves, as well as Conger Ice Shelf, which collapsed on March 15th, 2022. Following Watkins, Bassis, and Thouless (2021), we compute the power spectral density (PSD) between 90 and 3000 m wavelengths for each ice shelf’s surface topography. We also compute roughness values of each shelf, where roughness is defined as the square root of the integrated PSD. We find that Pine Island Glacier and Conger Ice Shelves have significantly higher magnitude PSD than Ross Ice Shelf at all computed wavelengths, with total roughness values almost two orders of magnitude higher. This is consistent with our expectations based on satellite imagery and ICESat-2 elevation profiles. To investigate whether the collapse at Conger Ice Shelf was associated with progressive structural changes, we compare topographic profiles recorded in 2020 and 2021. We do not observe any significant increase in roughness over the study period, suggesting that the collapse was a response to transient forcing and not gradual structural degradation related to surface roughness.
Amanda Saymsul: Calculating Cascadia subduction zone slip due to glacial loading
Faculty Advisor: Brad Lipovsky
Post-glacial rebound is the Earth’s response to the retreat of ice sheet retreat, thus, models of this process have been used to constrain post-glacial sea-level change. The post-glacial rebound uplift of Cascadia has been ongoing as a result of the decay of the Cordilleran ice sheet that has covered large parts of North America over the last ~2.6 million years. Models of glacial isostatic adjustment in the northern cascadia subduction zone are able to match rapid land uplift during glaciation, but require unusually low upper mantle viscosities. Hetzel & Hampel (2005) showed that lithospheric rebound caused by the regression of Lake Bonneville and deglaciation provides a possible mechanism for the high rates of faulting in the Wasatch region during the Holocene
(Figure 1). Adjacent to their work, this ongoing project aims to calculate the slip of the Cascadia subduction zone due to glacial loading in an idealized model. To evaluate the predicted behavior of a the Cascadia megathrust fault during glacial loading and unloading, we aim to design a finite-element model, which incorporates its thrust fault, to investigate the possibility that some of the land uplift following deglaciation was accommodated by motion along the subduction zone-megathrust interface. This project is still in the early stages of development.
Anjali Manoj: Glacial Insights from Alcoves in the Deuteronilus Mensae Region of Mars
Graduate Advisor: An Li
Faculty Advisor: Michelle Koutnik
Deuteronilus Mensae (40ºN-48ºN, 16ºE-35 ºE) is a region in the mid-latitudes of Mars that has landscapes with remnants of past glaciations as well as with recent radar studies showing presence of subsurface ice.
In this study, we focus on alcoves found along mesas in the region with the goal of studying their characteristics and the erosional processes that formed them, whether glacial or otherwise. We mapped out 1952 alcoves using Context Camera (CTX) images and High Resolution Stereo Camera (HRSC) digital elevation models. The alcoves were classified into 7 classes – 4 related to glacial processes and 3 related to other processes such as fluvial and crater impact. Subcategories were used to determine the type of material, if any, present in the alcoves.
We then drew our focus to those alcoves that had High Resolution Imaging Science Experiment (HiRISE) data available in order to study the alcoves at a higher resolution. We used digital elevation models made from CTX and HiRISEto produce geomorphic maps of the alcoves. In our preliminary observations from the mapping, we see distinct debris types such as layers, blocks, boulders and possible moraines found in certain alcoves in the simple and complex classes. We will then perform high resolution comparisons between the different alcoves including comparing slopes, thickness of layers, occurrence of boulders and volume of blocks to see what can be inferred about the processes that shaped these alcoves and if there is evidence for their glacial origin.
Through these investigations into the alcoves and the processes that shaped them, we aim to further our understanding on how alcoves on Mars may be categorized based on their features and what can be inferred about their origin. In doing so, we may be able to learn more about the glacial processes that shaped the Deuteronilus Mensae region.
Fig1: Geomorphic map of an alcove
Cody Cruz: Temperature Amplitude and Isotope Diffusion in Firn
Faculty Advisor: T.J. Fudge and Andy Schauer (Isolab)
Firn is the layer of snow compacting into ice at the surface of glaciers. The firn densifies to ice at ~120 m depth at the South Pole, with an age of 1000 years. The water isotope record of deuterium and oxygen-18 can be used in two ways to infer past temperature: 1) the traditional method associating a concentration of heavier isotopes with warmer temperatures and 2) an emerging method which uses the amount of diffusion the water isotope records have experienced. The primary question this project explores is how a change in the amplitude of the seasonal temperature cycle—but with the same mean temperature—affects the amount of diffusion in the water isotope record. We use the Community Firn Model (CFM) to explore this question. Creating input files for constant snow accumulation and sinusoidal atmospheric temperatures and isotope concentrations—to roughly simulate South Pole conditions—the CFM models the firn column for 1500 years to track isotope diffusion with depth. The model is forced at monthly time steps with constant accumulation, a fixed seasonal cycle for the water isotopes, and three amplitudes of the seasonal temperature cycle: 10,20, and 30°C from a mean of -50°C. The hypothesis was that greater amplitudes of seasonal temperatures would result in more diffusion. However, current model results only support this for the first ~100 years of diffusion and the rest of the firn column yields negligible difference due to atmospheric temperature amplitude. As firn is porous, densification occurs in air, increasing the complexity of interaction. One possibility is the effect on diffusion rates by firn temperature and tortuosity: perhaps increasing density and firn temperature fluctuations control diffusion more than initial surface temperatures. The model results will be used to interpret water isotope measurements from South Pole firn which are currently being processed at the UW IsoLab.
CFM isotope diffusion results. For both isotopes, the larger the seasonal temperature amplitude, the quicker diffusion occurs in the firn, averaging out the isotope values. Note that at around 100 years, the Lesser and Medium Temperature Amplitude diffusions catch back up to the Greater Temperature Amplitude diffusion
Jonathan H. Ortiz-Candelaria: Understanding Ice Temperature in Ice Streams in Antarctica and Greenland
Graduate Advisor: Ben Hills
Faculty Advisor: T.J. Fudge
The goal for this project is to understand temperature flow in glaciers throughout ice streams around Antarctica and Greenland. Specifically, the changes caused in temperature flow due to a glacier being transported downstream. As is known, the higher in elevation and more upstream a glacier is, the colder its overall temperature is along with the climate. This cold air and temperature in ice gets transported downward as it flows through the ice stream. This has different effects on the ice depending on the initial temperature, but most commonly it just makes ice temperatures colder. What we’re trying to understand is if this downstream temperature truly matters in the whole scheme of temperature flow. Usually, this downstream or longitudinal temperature flow is neglected due to the belief that it is a small change which makes it negligible. The issue that arises with this though is that when temperature predictions are compared to measured temperatures, there is a sizable difference. This sizable difference might just be caused due to the dismissal of longitudinal temperature flow. This is why this project aims to graph and analyze surface temperature, accumulation, and ice thickness data which contribute to internal glacial temperatures. With these analyses, we can determine how important longitudinal temperature flow truly is.
Fig 1. Graphs and Data for Thwaites Glacier
Sarothi Ghosh: Controls on water isotopes in a WAIS collapse scenario
Graduate Advisor: Lindsey Davidge
Faculty Advisor T.J. Fudge
One uncertainty in paleoclimate research is the extent of Antarctic ice loss during the Last Interglacial Period (125ka-116ka), though retreat of the West Antarctic Ice Sheet (WAIS) is likely. Water isotope ratios (such as H218O/H216O, known as δ18O) in ice cores near the WAIS may reflect WAIS collapse conditions; one goal of the future Hercules Dome ice core is to recover a record of potential isotope changes due to WAIS collapse. However, it will be important to understand how and why changes in δ18O occur in response to WAIS ice loss. The goal of this project is to use a 1-D, zonally averaged climate model to simulate water isotope variations caused by WAIS collapse. Zonally averaged temperature and hydrologic flux information from the Community Climate System Model (CCSM4) are used as input for the simple model, in order to disentangle global and local influences on variations in the water isotope profile. By comparing results from the simple model with more detailed simulations from 3-D global climate models, we can gain insight into the dominant controls on δ18O variations during WAIS collapse. Ultimately, this will be important for understanding the Hercules Dome isotope record.
2021 Projects
Jennifer Lomeli (UW): Upper and lower bounds of geothermal flux at Hercules Dome, Antarctica
Graduate Student Advisor: Gemma O’Connor
Faculty Advisor: T.J. Fudge
Program: Washington Space Grant Summer Undergraduate Research Program
Project Description: The largest unknown for estimating internal ice temperatures and hence the temperature of ice at the bed is the geothermal flux – the amount of heat flow from the earth into the base of the ice sheet. This value is poorly known across all of Antarctica because of the sparsity of measurements. The goal of this project is to use geophysical indications of both frozen and melting at nearby locations with different ice thicknesses to constrain the geothermal flux. Ice flows differently near an ice divide due to the low stress, such that the shape of the vertical velocity can be diagnostic of a frozen bed. Subglacial lakes can be identified with radar by their smooth surface and specular reflection. The presence of subglacial lakes indicates a thawed bed. Hercules Dome has indications of both a frozen bed beneath the divide at relatively shallow ice thicknesses (~1600m) and a melting bed at a lake under thicker ice (~2400m), which are separated by tens of kilometers. The project will use an ice-and-heat flow model to find the range of geothermal flux values that produce both a frozen bed at shallow ice thickness and a melted bed with thicker ice. The goal is for the student to have: determine the range of geothermal flux values consistent with the basal thermal constraints; gained experience performing scientific research; gained experience reading, interpreting, and communicating about scientific literature; gained a general understanding of ice-core science; gained skills in coding in Matlab; and aided the climatic understanding of a future deep ice core site in Antarctica.
Raphael Sauvage (UW): Effective Diffusivity of Sulfate in the Dome C ice core
Graduate Student Advisor: Ben Hills
Faculty Advisor: T.J. Fudge
Program: Washington Space Grant Summer Undergraduate Research Program
Project Description: The goal of this project is to understand how the sulfate record, dominated by the volcanic signal, is altered through time. Ice core analysis has revealed that the sulfur signal diffuses with age (depth), but the diffusivity is not well constrained. It is also not clear what controls the process of diffusion. The Dome C core from interior East Antarctica will allow an improved analysis of the effective diffusivity because there are multiple glacial-interglacial cycles. By using the volcanic peaks identified in only similar climate periods (i.e. all interglacial periods or all glacial maximums), the variability in the deposition can be largely eliminated. The goal is for the student to have: determined the effective diffusivity of sulfate using multiple interglacial and glacial periods; gained experience performing scientific research; gained experience reading, interpreting, and communicating about scientific literature; gained a general understanding of ice-core science; gained skills in coding in Matlab; and aided the understanding of future deep ice core sites in Antarctica.
Alexis Irvin (University of Florida): Modern climate of Hercules Dome, Antarctica
Graduate Student Advisor: Annika Horlings
Faculty Advisor: T.J. Fudge
Program: Cooperative Institute for Climate, Ocean, Ecosystem Studies (CICOES)
Project Description: The goal of the project is to better understand the interannual variations in climate at Hercules Dome (-86S, 105W) a future deep ice core site. Determining how the accumulation rate over Hercules Dome has varied in space and time is therefore important for interpreting the ice core at Hercules Dome and for modeling past ice flow. The primary climate reanalysis used will be ERA5 monthly averages. Highly temporally resolved (up to daily) reanalysis data may be needed to analyze storm directions. The goal is for the student to have: produced images/animation of each year’s annual accumulation in ERA5 to allow a qualitative comparison with the accumulation measured with radar; performed correlations of climate variables; gained experience performing scientific research; gained experience reading, interpreting, and communicating about scientific literature; gained a general understanding of ice-core science and climate reanalysis; gained skills in coding in Matlab and analysis of climate reanalysis output such as ERA5; and aided the climatic understanding of a future deep ice core site in Antarctica.
Victoria Johnson (UW): Ice Quake Hunting at the West Antarctic Ice Sheet Divide
Faculty Advisor: Brad Lipovsky
Program: Earth and Space Sciences Undergraduate Research
Project Description: Ice flow is like a lot of mini earthquakes and makes a lot of seismic noise. Observing and interpreting that noise is a challenge. This project seeks to find ice quakes in a location – an ice divide – where we do not expect them because of the low ice velocities. This research will help determine if ice quakes are being misidentified in faster flowing regions. The goal is for the student to have: applied algorithms for identifying ice quakes in seismic data ; gained experience performing scientific research; gained experience reading, interpreting, and communicating about scientific literature; gained skills in scientific computing; and aided the understanding of processes controlling ice flow in Antarctica.
2020 Projects
Linh Vu (UW): Determining effective diffusivity of sulfate using volcanic event widths
Faculty Advisor: T.J. Fudge
Program: Washington Space Grant Summer Undergraduate Research Program
Project Description: The goal of this project is to understand how the sulfate record, dominated by the volcanic signal, is altered through time. Ice core analysis has revealed that the sulfur signal diffuses with age (depth), but the diffusivity is not well constrained. It is also not clear what controls the process of diffusion. Using multiple ice cores, the spreading of the average width of volcanic events will be used to place constraints on the effective diffusivity. The goal is for the student to have: determined the effective diffusivity of sulfate using multiple ice cores; gained experience performing scientific research; gained experience reading, interpreting, and communicating about scientific literature; gained a general understanding of ice-core science; gained skills in coding in Matlab; and aided the understanding of future deep ice core sites in Antarctica.
2019 Project
Elizabeth Urban (UW): Upper limits of geothermal flux from Raymond Arches observed around Antarctica
Faculty Advisor: T.J. Fudge
Project Description: Geothermal flux is an important input parameter for modeling the Antarctic Ice Sheet and estimating future sea level changes. High geothermal flux results in basalt melt of an ice sheet, which increases water flow and allows sliding. Direct measurements of geothermal flux in Antarctica are rare, as the ice-bedrock interface is buried under hundreds to thousands of meters of ice. Raymond arches indicate a coastal dome is frozen at the bed and is a site that can be used to calculate maximum geothermal flux. The maximum geothermal flux is estimated by inputting site-specific data of ice thickness, accumulation rate and surface temperature into an ice-and-heat flow model for coastal domes. When a basal temperature is also available, the geothermal flux can be calculated. Sixteen coastal domes were modeled in this project. Geothermal flux was calculated for four sites and maximum geothermal flux was calculated for twelve sites. These results are compared against two continent-wide models of geothermal flux, based off Curie depths and seismic wave refraction. On Adelaide Island, the continental models do not agree, and this site-specific model returns a value in between their geothermal flux estimates, which suggests that the greater geothermal flux estimate is too high. In Dronning Maude Land, the site-specific maximum geothermal flux values are regionally consistent and indicate what site characteristics produce significant results. Sites with greater ice thicknesses, lower accumulation rates, and warmer surface temperatures yield lower maximum geothermal flux estimates, which are more useful in constraining the geothermal flux.
2018 Project
Surahbi Biyani (UW):
Constraining Geothermal Flux at Coastal Domes of the Ross Ice Sheet, Antarctica
Faculty Advisor: T.J. Fudge
Project Description:The geothermal flux is an important boundary condition for ice‐sheet models because it influences whether the ice is melting at the bed and able to slide. Point measurements and remotely sensed estimates vary widely for the Ross Ice Sheet. A basal temperature measurement at Roosevelt Island reveals a geothermal flux of 84 ± 13 mW/m2. The presence of Raymond Arches, which form only at ice divides that are frozen at the bed, allows inferences of the maximum geothermal flux at two coastal domes along the Siple Coast: Engelhardt Ridge, 85 ± 11 mW/m2 and Shabtaie Ridge, 75 ± 10 mW/m2. These measurements indicate heat flows similar to measurements at Siple Dome and the Whillans grounding zone and to the continental crust average. The high values measured at Subglacial Lake Whillans and estimated from satellite observations of Curie depths are not widespread.
TJFudge 