25 Aug 2022

McMurdo Snow Roads and Transportation: Final Program Summary

Abstract: The snow roads at McMurdo Station, Antarctica, are the primary transportation corridors for moving personnel and material to and from the airfields servicing intra- and intercontinental air traffic. The majority of the road system is made of snow overlying a snow, firn, and icy subsurface and is particularly susceptible to deterioration during the warmest parts of the austral summer when above-freezing temperatures can occur for several days at a time. Poor snow-road conditions can seriously limit payloads for all types of ground vehicles. The US Army Cold Regions Research and Engineering Laboratory (CRREL) studied the McMurdo snow roads for the National Science Foundation Office of Polar Programs as part of the Snow Roads and Transportation (SRT) program. The goals of the SRT program was to improve construction, maintenance, and use of the McMurdo’s snow roads, with particular attention on minimizing warm-season deterioration. This is the final report of the SRT program, summarizing the program’s activities and findings and emphasizing those parts of the program not previously documented in CRREL Reports, conference papers, or journal articles.

5 Aug 2022

South Pole Station Snowdrift Model

Abstract: The elevated building at Scott-Amundsen South Pole Station was designed to mitigate the effects of windblown snow on it and the surrounding infrastructure. Because the elevation of the snow surface increases annually, the station is periodically lifted on its support columns to maintain its design height above the snow surface. To assist with planning these lifts, this effort developed a computational model to simulate snowdrift formation around the elevated building. The model uses computational fluid dynamics methods and synthetic wind record generation derived from statistical analysis of meteorological data. Simulations assessed the impact of several options for the lifting operation on drifts surrounding the elevated building. Simulation results indicate that raising the eastern-most building section (Pod A), or the entire station all at once, can reduce drift accumulation rates over the nearby arches structures. Long-term analyses, spanning 5–6 years, determine whether an equilibrium drift condition may be reached after a long period of undisturbed drift development. These simulations showed that after about 6 years, the rate of growth of the upwind drift slows, appearing to approach an equilibrium condition. However, the adjacent drifts were still increasing in depth at a roughly linear rate, indicating that equilibrium for those drifts was still several seasons away.

5 Aug 2022

SAGE-PEDD Theory Manual: Modeling Windblown Snow Deposition around Buildings

Abstract: Numerical modeling of snowdrifting is a useful tool for assessing the im-pact of building design on operations and facility maintenance. Here we outline the theory for the SAGE-PEDD snowdrift model that has applica-tion for determining snowdrift accumulation around buildings. This model uses the SAGE computational fluid dynamics code to determine the flow field in the computational domain. A particle entrainment, dis-persion, and deposition (PEDD) model is coupled to SAGE to simulate the movement and deposition of the snow within the computational do-main. The report also outlines areas of future development that upgrades to the SAGE-PEDD model should address.

5 Aug 2022

SAGE-PEDD User Manual

Abstract: SAGE-PEDD is a computational model for estimating snowdrift shapes around buildings. The main inputs to the model are wind speed, wind direction, building geometry and initial ground or snow-surface topography. Though developed mainly for predicting snowdrift shapes, it has the flexibility to accept other soil types, though this manual addresses snow only. This manual provides detailed information for set up, running, and viewing the output of a SAGE-PEDD simulation.

31 Mar 2022

Continued Investigation of Thermal and Lidar Surveys of Building Infrastructure

ABSTRACT: We conducted a combined lidar and thermal infrared survey from both ground-based and Unmanned Aerial System (UAS) platforms at McMurdo Station, Antarctica, in February 2020 to assess the building thermal envelope and infrastructure of the Crary Lab and the wet utility corridor (utilidor). These high-accuracy, coregistered data produced a 3-D model with assigned temperature values for measured surfaces, useful in identifying thermal anomalies and areas for potential improvements and for assessing building and utilidor infrastructure by locating and quantifying areas settlement and structural anomalies. The ground-based survey of the Crary Lab was similar to previous work performed by the team at both Palmer (2015) and South Pole (2017) Stations. The UAS platform focused on approximately 10,500 linear-feet of utilidor throughout McMurdo Station. The datasets of the two survey areas overlapped, allowing us to combine them into a single, georeferenced 3-D model of McMurdo Station. Coincident exterior temperature and atmospheric measurements and Global Navigation Satellite System real-time kinematic surveys provided further insights. Finally, we assessed the thermal envelope of the Crary Lab and the structural features of the utilidor. The resulting dataset is available for analysis and quantification.

20 Aug 2020

PUBLICATION NOTICE: Concept for Artificial Freezing of Sea Ice at Winter Quarters Bay, Antarctica

ABSTRACT:  McMurdo Station serves as a major research and logistics hub for the United States Antarctic Program (USAP). Adjacent to the Station is Winter Quarters Bay (WQB), where vessels dock to unload cargo and fuel. The ice pier at McMurdo is essential for this annual vessel resupply but represents a failure potential, occasionally breaking up during or immediately after vessel operations. This study aimed to determine the feasibility of using thermopiles, a passive cooling technology, to artificially freeze seawater to “grow” the existing WQB bottomfast-ice edge so that ships can dock directly against it. Finite element simulations using modeling-parameter assumptions indicate that each row of thermopiles can grow a frozen wall to a depth of 9 m in about a month if installed on 1 July with an initial sea-ice thickness of 1 m and a thermopile spacing of 1.5 m. For our simulation scenarios, we approximate that it would take 255 to 820 days to complete a 40 m by 140 m wedge of bottomfast ice. The estimated cost ranges from about $600,000 to $1,600,000. These results serve as a preliminary feasibility study of successfully using thermopiles for generating a direct docking bottomfast-ice wharf at McMurdo.

25 Jun 2020

PUBLICATION NOTICE: A Generalized Approach for Modeling Creep of Snow Foundations

ABSTRACT:  When an external load is applied, snow will continue to deform in time, or creep, until the load is removed. When using snow as a foundation material, one must consider the time-dependent nature of snow mechanics to understand its long-term structural performance. In this work, we develop a general approach for predicting the creep behavior of snow. This new approach spans the primary (nonlinear) to secondary (linear) creep regimes. Our method is based on a uniaxial rheological Burgers model and is extended to three dimensions. We parameterize the model with density- and temperature-dependent constants that we calculate from experimental snow creep data. A finite element implementation of the multiaxial snow creep model is derived, and its inclusion in an ABAQUS user material model is discussed. We verified the user material model against our analytical snow creep model and validated our model against additional experimental data sets. The results show that the model captures the creep behavior of snow over various time scales, temperatures, densities, and external loads. By furthering our ability to more accurately predict snow foundation movement, we can help prevent unexpected failures and extend the useful lifespan of structures that are constructed on snow.

13 May 2020

PUBLICATION NOTICE: Assessment for Soil Reuse Standards at McMurdo Station

Abstract:  The soils at McMurdo Station in Antarctica contain hydrocarbons derived from accidental fuel spills and industrial development. The current practice for contaminated soils is to remove any material with concentrations greater than 100 mg/kg of total petroleum hydrocarbons (TPH) and to transport them to the United States for disposal. Any soils that contain concentrations of TPH less than 100 mg/kg can be reused on-site. While this is the current standard practice, there remains little evidence to verify that 100 mg/kg is an appropriate reuse standard. Moreover, the current practice is based on the guidelines for cleanup values in California (the port of entry where the soils are currently shipped for treatment and disposal), which has few environmental similarities with Antarctica. In the present study, we investigate current regulations for cleanup and soil reuse in U.S. states, Canadian territories, and other countries with cold climates. We also discuss case studies from Arctic and Antarctic regions where soil has been reused after treatment. Additionally, we present a site conceptual model for risk assessment based on known site information and recommend future focus areas for addressing hydrocarbon-contaminated soils at McMurdo Station.

12 May 2020

PUBLICATION NOTICE: Fenton’s Reagent Treatability Study for Hydrocarbon-Contaminated Soils, McMurdo Station, Antarctica

ABSTRACT:  Hydrocarbon-contaminated soil is distributed heterogeneously at McMurdo Station, Antarctica, which has served for over 60 years as the logistics hub for the U.S. Antarctic Program. Here we investigated the treatability of McMurdo Station’s contaminated soil with chemical oxidation. Our study collected five soil samples in 2018 and 2019, of which two contained high levels (>100 mg/kg) of total petroleum hydrocarbons (TPH) suitable for the treatability study. One soil (ITC) was characterized by 1250 mg/kg of predominantly midrange (n-C8 to n-C16) hydrocarbons, and the other (Soil Pile) was characterized by 3500 mg/kg of predominantly heavy molecular weight (>n-C21) hydrocarbons. We investigated the treatability of these soils with both Fenton’s Reagent (pH < 3 with Fe2+) and modified Fenton’s Reagent (chelated Fe2+), each with hydrogen peroxide concentrations of 3% and 10%. Soil slurries were placed on a shaker table at 100 rpm and 4°C for up to 21 days. TPH concentrations were reduced by approximately 50% for ITC; however, the oxidative treatments did not out-perform controls. All treatments and controls yielded no significant reduction in Soil Pile TPH. Poor performance by these chemical oxidation treatments indicates that remediation of hydrocarbons at these sites may require further soil processing in combination with chemical oxidation or alternative treatment technologies.

7 Apr 2020

PUBLICATION NOTICE: Snow-Road Light-Truck Tire Testing

 Link: http://dx.doi.org/10.21079/11681/35514Report Number: ERDC/CRREL TR-20-2Title: Snow-Road Light-Truck Tire TestingBy Terry D. Melendy Jr., Amelia Menke, Daphnie C. Friedman, and Reed R. WinterApproved for Public Release; Distribution is Unlimited February 2020ABSTRACT:  The United States Antarctic Program (USAP) anticipates replacing the