Title : Blue-ice and snow runways < Type : Antarctic EAM NSF Org: OD / OPP Date : April 09, 1993 File : opp93103 INITIAL ENVIRONMENTAL EVALUATION DEVELOPMENT OF BLUE-ICE AND COMPACTED-SNOW RUNWAYS IN SUPPORT OF THE U.S. ANTARCTIC PROGRAM National Science Foundation Office of Polar Programs Washington, DC April 9, 1993 1. INTRODUCTION The U.S. Antarctic Program (USAP) is proposing to develop one or more runways suitable for wheeled aircraft to support its scientific activities. Concepts for such runways include "blue-ice" runways on glacier ice and runways on compacted snow. The Supplemental Environmental Impact Statement (SEIS) on the USAP (NSF 1991) identified the development of such runways as an ongoing USAP planning activity. The purpose of this Initial Environmental Evaluation (IEE), the equivalent of an Environmental Impact Assessment, is to evaluate in more detail potential environmental impacts that might result from developing blue-ice and compacted-snow runways. This IEE is prepared by USAP in compliance with the National Environmental Policy Act, the Antarctic Treaty, and the Protocol on Environmental Protection to the Antarctic Treaty (the Madrid Protocol) adopted by 26 countries in 1991. 1.1 BACKGROUND The National Science Foundation (NSF) is responsible for the U.S. Antarctic Program (USAP) that supports a substantial scientific research program in Antarctica, often in cooperation with other countries. The USAP maintains three year-round stations in AntarcticaşMcMurdo Station on Ross Island, the Amundsen-Scott South Pole Station, and Palmer Station on the Antarctic Peninsula (Fig. 1). McMurdo Station is the major base for providing logistic support to numerous scientific field camps on the continent each austral summer. Logistic and operational support is provided by the Department of Defense (Naval Support Force Antarctica, U.S. Army, and U.S. Air Force), the U.S. Coast Guard, and a civilian contractor (currently Antarctic Support Associates, Inc). An essential component of USAP logistic support is provided by aircraft that transport personnel and cargo to McMurdo, the South Pole, and field sites during the austral summer season (October through February). A runway for wheeled aircraft is constructed on the annual sea-ice at the start of each season and is used until early December when the sea ice begins to deteriorate. Wheeled aircraft, including C-130 Hercules, C-141 Star Lifters, and C-5 Galaxies, are able to land on the annual sea-ice runway. They provide the majority of the air transport needed for the initial stages of USAP activities each season. During the rest of the season (December through February), fixed-wing aircraft support is limited to ski-equipped LC-130 aircraft and smaller aircraft (for example, ski-equipped Twin Otters) that can land on skiways at Williams Field near McMurdo, the South Pole Station, and field sites. Availability of runways suitable for landing wheeled aircraft during other parts of the season (or if feasible, throughout the year) would greatly enhance USAP's ability to support science activities and help the program streamline its logistic support efforts by increasing the flexibility and efficiency of aircraft operations. 1.2 PHILOSOPHY OF THE U.S. ANTARCTIC PROGRAM IN MINIMIZING ENVIRONMENTAL IMPACTS Reducing human impacts on the antarctic environment is a major goal of the USAP. Enhancing the use of wheeled aircraft can help meet the goal of streamlining antarctic operations. Aircraft are essential for supporting scientific research, but their fuel, emissions, and the personnel required to operate and maintain them can cause environmental impact on Antarctica. Wheeled airplanes are appreciably more efficient in that they use less fuel and can carry more cargo than similar aircraft equipped with skis. Replacing ski-equipped planes with wheeled aircraft could reduce the number of flights, the consumption of fuel, and the generation of emissions and maintenance-related wastes required to support USAP scientific and operational activities. The operating philosophy of the USAP (Draggan and Wilkniss 1993) recognizes the potentially profound impacts that its presence and its activities can have upon Antarctica. This philosophy acknowledges the importance of the various components of the human environment, the antarctic environment, and the interactive processes that give structure to those environments. The philosophy goes further in affirming that USAP will use all practicable means and measures to foster and maintain Antarctica's natural conditions while promoting and supporting antarctic scientific endeavors in a manner that is safe and healthful for USAP participants. The USAP's operating philosophy is based upon several broad, yet reasonable and practical, assumptions. The assumptions are that: (1) the Antarctic Continent can be viewed, in the main, as a closed environment; (2) inputs to, and outputs from, the operating environments of the USAP (that is, its stations, field camps and vessels) can be controlled; (3) while all human activities entail some measure of change or impact to the environment, those changes and impacts can be minimized, mitigated, or controlled; and, (4) effective minimization, mitigation, and control of change or impact depends on information-intensive approaches that foster early consideration of potential changes or impacts. In keeping with this philosophy, this IEE focuses on actions or changes to program activities that might: (1) reduce human impacts by reducing the need for antarctic personnel and non-science support operations; (2) foster environmentally-compatible use of such natural antarctic substrates as ice and snow; and (3) promote reductions in peaks of operational activity by providing opportunities for year-round program operation. 1.3 SCOPE OF THE IEE This IEE evaluates the impacts associated with developing blue-ice and compacted-snow runways in general, as well as current proposals to develop such runways at the Pegasus site near McMurdo Station and at Mill Glacier or Mount Howe. The intent is to provide sufficient evaluation to ensure that adequate review of potential environmental impacts for planned developments of such runways has been done and appropriate documentation prepared. This analysis will be reviewed for future developments, and supplemental analysis and documentation will be prepared for such developments as necessary. 2. THE PROPOSED ACTION AND ALTERNATIVES The proposed action is to develop a limited number of blue-ice or compacted snow runways to support USAP activities. The proposed action includes development of a runway at the Pegasus site near McMurdo to allow use of wheeled aircraft and at Mill Glacier or Mount Howe. Alternatives include consideration of alternative locations and alternative construction techniques. 2.1 PURPOSE AND NEED 2.1.1 Purpose The purpose of the proposed action is to construct and operate blue-ice and compacted-snow runways in Antarctica that would be used by wheeled aircraft and would enhance air support for USAP activities throughout the austral summer season and possibly throughout the year. In the near term, USAP is exploring the possibilities of developing: (1) a blue-ice or compacted-snow runway on the permanent ice shelf near McMurdo Station that could be used by wheeled aircraft late in the season and (2) a blue-ice or compacted-snow runway that could be used by wheeled aircraft to support construction activities at the South Pole Station. In addition, blue-ice or compacted-snow runways may also be developed elsewhere in Antarctica in the future to support USAP scientific and logistic support activities. Runways suitable for wheeled aircraft could be important in emergencies. In August 1987, NSF Director Erich Bloch convened a panel of experts to review safety in the USAP (USAP Safety Review Panel 1988). The panel was tasked to review "...all aspects of safety in NSF, DOD, U.S. Coast Guard, support contractor, and science team operations." Two of their recommendations are relevant to this proposed action. Recommendation AOP-2 was that "...the National Science Foundation should consider evaluating "blue ice" areas as potential LC-130 landing sites to provide greater flexibility for science and operational purposes." Recommendation AOP-3 was "...to investigate and define the means by which both early (or episodic) and year-round access to McMurdo can be provided safely." Part of the motivation for both these recommendations was better access in emergencies. 2.1.2 Need for a Blue-Ice or Compacted-Snow Runway at McMurdo Currently, wheeled aircraft fly to and from McMurdo Station between October and early December when a hard-surfaced, annual sea-ice runway is available. At other USAP sites on the continent, including the South Pole Station, ski-equipped aircraft land on prepared skiways. When the McMurdo annual sea-ice runway is shut down in December, fixed-wing aircraft support is restricted to a limited number of ski-equipped aircraft owned or chartered by USAP. The USAP currently owns six ski-equipped LC-130s and may charter two additional ski-equipped LC-130s from the Air National Guard, that usually are available in November and January. In addition, USAP may charter one or two Twin Otters (or similarly equipped aircraft) to support science projects and provide other types of support (for example, reconnaissance surveys). From December through February, LC-130s are used to provide both intercontinental air transport between New Zealand and McMurdo and intracontinental support to the South Pole and field sites beyond the range of helicopter operations. The small number of large ski-equipped aircraft available limits both the amount of science that can be supported in January and February and the program's flexibility in accommodating unanticipated needs. A blue-ice or compacted-snow runway near McMurdo that would operate in late January through February would allow wheeled aircraft to transport personnel leaving Antarctica at the end of the austral summer season back to New Zealand. Wheeled aircraft would carry more passengers per flight and would require fewer trips than would LC-130s. By using wheeled aircraft at McMurdo late in the season, LC-130s that are currently used to redeploy personnel to New Zealand would be available to provide additional support for science at the South Pole Station and field sites. If more research were to take place on a continuous, year-round basis, the capability to land aircraft at McMurdo year-round would be a major advantage in terms of safety. Year-round access is not being considered by USAP at this time. If it should be deemed feasible in the future, USAP would conduct additional environmental review to assess the potential environmental impacts and would prepare appropriate documentation. 2.1.3 Need for a Runway to Support Construction Activities at the South Pole Station Another need for a blue-ice or compacted-snow runway is to facilitate the transport of construction materials that would be needed for any reconstruction or replacement of the South Pole Station within the next ten years. Although the reconstruction or replacement of the South Pole Station would be addressed in detail in separate environmental documentation, the development of a blue-ice or compacted-snow runway to support this action is addressed in this IEE. Use of LC-130s for transporting construction materials could significantly reduce their availability to support the science program at the South Pole and elsewhere. 2.1.4 Need for Runways to Support Field Camps or Enhance Safety Other blue-ice runways may be developed by USAP to provide (1) alternative landing sites for wheeled aircraft if the sea-ice runway at McMurdo is shut down by poor weather conditions; (2) a refueling site for wheeled aircraft flying from South America to McMurdo; or, (3) logistic support bases for future science projects. The need for such sites would be defined to enhance safety, to make the best use of the limited LC-130 assets, and to limit the number of flights required. 2.2 ALTERNATIVE ACTIONS Alternatives considered in this IEE fall into three groups, as follows: (1) alternatives for enhancing use of wheeled aircraft at McMurdo Station; (2) alternatives for improving air logistics support to the South Pole Station; and, (3) alternatives for improving wheeled aircraft support to USAP activities elsewhere on the continent. These three groups of alternatives are discussed in the following sections. 2.2.1 Enhancement of Wheeled Aircraft Capabilities near McMurdo Station Actions considered in this section include: 1) the proposed action of developing a blue-ice or compacted-snow runway at the Pegasus site near McMurdo Station (Fig. 2); and 2) the no-action alternative of continuing the current practice of using a combination of a sea-ice runway and skiway at McMurdo. 2.2.1.1 Development of a compacted-snow runway at the Pegasus site (Pegasus I) The USAP, with the assistance of the Cold Regions Research and Engineering Laboratory (CRREL), has been investigating the feasibility of constructing either a compacted-snow (Pegasus I) or a blue-ice runway (Pegasus II) at the Pegasus site since 1987 (Fig 3). The Pegasus site is the only blue ice (snow ablation zone) in reasonable proximity to McMurdo Station. A Pegasus runway would be 10,500 ft long and would be located on the ice shelf between Black and White Islands, known as "Herbie Alley", oriented approximately north-south towards McMurdo (Fig. 3). As noted earlier, the main use is anticipated to be re-deployment of personnel at the end of the austral summer season in February. Once proven, the possibility of using the runway for winter-fly- in ("WINFLY") and of accessing McMurdo Station during the winter may be considered. Work at the Pegasus site was initiated during the 1989-90 season and has continued through the 1992-93 season. Environmental impacts of the experimental work performed were addressed in an Environmental Action Memorandum (NSF 1990) prepared in October 1990. The concept for the Pegasus I runway is to prepare a compacted-snow runway by placing and subsequently compacting a thin (25-cm) layer of snow over the blue-ice base (Blaisdell et al. 1992). Initial work on the Pegasus I runway involved stripping off the snow cover into windrows and redistributing the snow with graders and snow planes. The snow was compacted using a variety of machinery that was available at McMurdo and Williams Field. The density of the compacted snow that was obtained was not sufficiently great to support test landings during the first season. When conditions were favorable in the following December (1991), the runway was compacted with a heavy pneumatic-tire roller. Problems were encountered with snow melt at the southern end of the runway and much of the snow cover was lost in January at that end of the runway. Two test landings were made on the Pegasus runway during the 1991-92 season. An empty LC-130 on a return flight from the South Pole made a ski landing then taxied on wheels the full length of the runway and took off. The second test landing involved a fully loaded LC-130 that took off from Williams Field and then landed on skis at the Pegasus site. Also, this flight taxied and took off from the Pegasus site on wheels. The results of these test landings and takeoffs were considered to be very successful and have demonstrated that compacted-snow pavements can be made sufficiently strong for wheeled C-130 operations. Development of the Pegasus I runway is not being pursued at this time. The concept might be revived if the Pegasus II concept proves to be unworkable. The principal difference between the two is that a considerable amount of effort is required to roll and compact snow to form a firm surface layer upon which wheeled aircraft can land. It is not clear whether the effort required to develop the required surface strength is less or more than required to prepare a blue-ice runway. 2.2.1.2 Development of a blue-ice runway at the Pegasus site (Pegasus II) The concept for the Pegasus II runway is to develop a runway directly on exposed blue ice. Because melt pools can form on exposed blue-ice during the warmest periods of the austral summer (November through January), snow would be spread over the exposed surface to protect it from the sun during this time. In late January, this snow cover would be cleared to expose the blue-ice landing surface so that the runway could be used for redeploying personnel to New Zealand. Because of difficulties with Pegasus I, planning for the 1992-93 season focused on Pegasus II. Early in the season, snow was removed from the proposed Pegasus II runway. Using a laser- guided grader, irregularities and high spots were removed to produce a smooth and nearly level surface. The runway surface successfully supported a test cart equipped to produce loadings similar to a C-130 aircraft landing gear. Tests with a cart setup to reproduce the loading of a C-141 aircraft landing gear caused failure of the surface in three spots. These spots are believed to have undergone melting in the previous season. The spots were patched, but trial C-141 landings were postponed to give the patches time to anneal. During the remainder of November, December, and January the surface was covered with snow to prevent melt pool formation. Snow removed from the surface in October was redistributed to minimize the likelihood of drifting that would cover Pegasus II with quantities of snow that would be difficult to remove in subsequent years. In late January and early February 1993, the Pegasus II runway tested satisfactorily for landings of C-130s. Several roundtrip flights were made during February to redeploy personnel at the end of the 1992-93 season. The runway at the Pegasus site was constructed with a 14G laser-guided grader, a snow blower, a snow plane, a bulldozer, two towed rollers, and a load cart (that is, a cart equipped with C-130 or C-141 wheels and loaded with sufficient weight to simulate the pressure of a taxiing C-130 or C-141 aircraft) to test the runway surface. The grader was used for initial preparation to remove bumps or waves in the runway surface, but the overall slope of the surface was not modified. A snow blower was used to clear snow so the surfaces could be prepared, to remove ice removed by the grader, and to cover the prepared surface with snow to prevent formation of melt ponds during the warmest parts of the season. Construction of the runway required six people full time, and about the same size crew is required to maintain the snow cover during the November-January period. Maintenance of the Pegasus II runway is basically a snow management problem. Because of the particular requirements of the Pegasus glacier-ice runway, both snow drifting and activities that reduce the albedo of the ice or snow surface must be carefully controlled. To minimize snow drifts, only the minimum of facilities, primarily fuel tanks, and sanitary and emergency facilities needed to support the 4 to 6 people working at the site would be located there during the warm part of the season. During the austral winter, when the runway is not in use, all structures and navigational aids would be removed. In addition to constructing the runway surface, shelters would be moved to the site to provide support facilities for the Pegasus site. These shelters, including an emergency shelter, a heated rest facility, and a toilet facility, would initially be portable or temporary facilities. The use of portable structures would reduce long-term problems with drifting snow. If more permanent facilities are needed in the future, they would be elevated above the surface to minimize snow drifting. A crash truck from Williams Field would be stationed at the runway when flights were scheduled. Other emergency vehicles (for example, ambulances) would be available at Williams Field in the event of an accident. Fuel would be temporarily stored on site to refuel aircraft, and all wastes, with the possible exception of grey water which might be piped through the ice into the sea below, would be taken to McMurdo. Initially, the fuel would be taken to Pegasus in two small tanks mounted on sleds; the empty tanks would be returned to Williams Field. Initially, no precision radar or TACAN would be required, and no power would be generated on site. Testing would probably only require a flagged runway. Should Pegasus be used to extend the season, runway lights would be needed in addition to other navigation aids similar to those used at Williams Field and the sea-ice runway. If the runway proves successful and the facilities take on a more permanent nature, radar installation and power generation also would be required. Fuel would then be stored in a skid-mounted storage tank. Secondary containment for the tanks would be provided to prevent fuel spills onto the snow and ice. Most aircraft and vehicles used in Antarctica leak oil and hydraulic fluid. These leaks would have to be controlled and promptly cleaned up at Pegasus because of their effect on the runway's albedo. On sunny days, the increased albedo caused by leaking oil and hydraulic fluid could cause local melting that would damage the surfaces of the runway and taxiway. Pick-up trucks, vans, Deltas, or rubber-tracked Challengers would be used to transport personnel and equipment to and from the site initially. Snow that accumulates or drifts on the access roads to the Pegasus site would be leveled and compacted. Routine maintenance of vehicles and equipment would be performed at Pegasus or Williams Field. If necessary, major repairs would be done at McMurdo. The snow road to the Pegasus site is basically a straight line that runs approximately 13 km from Williams Field. This road comes close to the edge of the ice shelf and would have to be relocated periodically as the ice shelf moves. The ice shelf is moving west at a rate of approximately 100 m/year in this area but at less than half that rate at the Pegasus site. This movement is being monitored. If the Pegasus II runway development continues to be successful, it would supplement, rather than replace, the sea-ice runway and the Williams Field skiway, primarily at the end of the austral summer season. The annual sea-ice runway would continue to be used because it is inexpensive, its location is very close to McMurdo, and preparation time and effort is minimal. The Williams Field skiway would continue to be used at McMurdo because no hard-surface runway would be available during the warmest parts of the austral summer season (December and January). The Pegasus site would probably be developed gradually and decisions on whether and how long to use it would be made on the basis of experience. 2.2.1.3 No-Action alternative at the Pegasus site Under the no-action alternative, USAP would continue to use only the annual sea-ice runway and Williams Field as runways for fixed-wing aircraft. The sea-ice runway is constructed each year on annual sea ice as close to McMurdo Station as possible; its exact location may vary from year to year, depending on ice conditions and other considerations. The support buildings associated with the sea-ice runway are mounted on sleds and moved each year to and from Williams Field. Construction of the sea-ice runway begins in August when additional support personnel are flown to McMurdo to prepare the station for opening. Operation of the runway begins in early October. The Williams Field skiway is approximately 16 km from McMurdo Station on the Ross Ice Shelf. Williams Field is located on the ice shelf that is moving slowly toward the sea. The skiway and its associated facilities are periodically relocated to avoid loss when the ice calves into McMurdo Sound. These facilities are described in more detail in the SEIS (NSF 1991). 2.2.2 Support for the South Pole Station The present South Pole Station was completed in 1975 and is being buried by accumulated snow. The station has exceeded its design life, and the current summer population greatly exceeds the number of people for which it was designed. The current station is supported by a skiway that typically operates from late October to late February each year. As plans are being developed for any new station, the feasibility of transporting the millions of pounds of material and equipment that would be needed using LC-130 aircraft is being examined. Use of the limited LC-130s available for this purpose would have a significant impact on their availability to support current and planned scientific activities at the South Pole Station. Thus, the USAP is investigating the feasibility of transporting materials and equipment in conventional, wheeled aircraft to a blue-ice runway as close to the Station as practicable. Cargo would then be transported the remaining distance by overland traverse tractor-pulled sleds or tracked trailers over the snow/ice surface. The possibility of developing a blue-ice runway to support reconstruction of the South Pole Station has received considerable attention. Studies by Swithinbank (1989, 1991) and Mellor and Swithinbank (1989) have identified potential blue-ice landing sites throughout Antarctica. These studies have narrowed the sites suitable for supporting reconstruction of the South Pole Station to two that are currently being examined in detail. The Mount Howe site is located about 300 km from the South Pole Station, and the Mill Glacier site is located about 540 km from the South Pole Station (Fig. 4). Sites at Mount Howe and Mill Glacier (300 km and 540 km from the South Pole, respectively) are being investigated by the CRREL as the closest, potentially feasible blue-ice sites to the South Pole. Another alternative that is being examined is to develop a compacted-snow runway at the South Pole Station itself. The feasibility of constructing such a runway is not clear at this point in time, but the advantages of being able to land wheeled aircraft at the South Pole would be enormous. Other alternatives for transporting construction materials and equipment to the South Pole do not involve development of blue-ice or compacted-snow runways and are beyond the scope of this IEE. These alternatives include overland traverse from McMurdo Station, air drops, and use of dirigibles. The no-action alternative would depend on the use of LC-130s to transport all construction materials and equipment. 2.2.2.1 Development of a blue-ice runway at Mount Howe The closest potential blue-ice runway site to the South Pole is at Mount Howe, where the exposed blue-ice surface is suitable as a runway with relatively little smoothing. Twin Otter aircraft have already landed there on wheels. Intensive summer warming that mandates a protective cover at the Pegasus site during December and January does not occur at Mount Howe. Thus no annual surface protection measures are necessary at this site. It is expected that wheeled landings can be made on a selected area of the natural blue-ice surface by lightly loaded LC-130s. Surveys are being conducted to locate and mark such an area. LC-130s would land there to deliver equipment to smooth the surface for a longer, smoother permanent runway. The equipment would include a towed road brush which, with the help of the wind, would remove any loosened material from the runway. The only maintenance needed thereafter should be periodic brushing to dislodge patches of snow from the blue-ice surface and the prompt removal of oil and hydraulic fluid that leaks from aircraft and vehicles. In this fashion it is expected that a suitable surface can be formed on which C-130 and C-5 aircraft could land. It is not yet known if a surface can be produced that would allow C-141 aircraft to land at Mount Howe. Because the U.S. Air Force may not wish to have C-5 aircraft land in such a remote location, it is most likely that C-130s would be used at Mount Howe. While few LC-130 aircraft are available, many C-130s could be made available by the USAF. The characteristics of the Mount Howe site do not permit the runway to be aligned with the often strong winds present there. The cross-wind component of these winds would prevent landings at times. In January 1992, an Automated Weather Station was installed at Mount Howe to monitor wind conditions. It is possible that the operational window at Mount Howe will be too small to make it a landing site. Initial reconnaissance of the over-snow traverse route from Mount Howe to the South Pole indicates that the route is potentially crevasse-free and of reasonable slope, except for one area about 12 km from the Mount Howe runway site. If the Mount Howe site were developed, facilities would be built to accommodate a crew of 6-12 that would operate the airfield, unload the aircraft, and load the traverse sleds (or tracked trailers ) and the members of the traverse crews. The Mount Howe runway would operate only during the austral summer, perhaps from late October through early December. However, other developments, such as the Pegasus runway, might make it possible to expand the period during which the Mount Howe airfield is operational. Traverses between Mount Howe and the South Pole could continue throughout the season if sufficient cargo is transported to Mount Howe to warrant them. Aircraft carrying cargo to Mount Howe could originate at either Christchurch, New Zealand, or McMurdo. In specific situations, several aircraft could land at Mount Howe on a given day. Some heavy equipment would be needed at Mount Howe to unload aircraft and reload the traverse sleds (or tracked trailers) rapidly when they arrive. A building in which this equipment can be stored and maintained would be needed at the site. Platforms would be needed for staging palletized aircraft loads until they are transferred to sleds (or tacked trailers) to keep the cargo and the staging area from being engulfed in drift snow. 2.2.2.2 Development of a blue-ice runway at Mill Glacier No runway construction activity would be needed for use of the blue-ice runway at the Plunket Point site on Mill Glacier. Twin-Otter and LC-130s have landed at this site in the past. Operational requirements and maintenance activities would be similar to those at Mount Howe. Because the Mill Glacier site is farther from the South Pole Station than the Mount Howe site (540 km vs 300 km), additional fuel storage for traverse vehicles would be needed. Cargo transport by tractor train to the South Pole would require more time and fuel than the traverse from Mount Howe. This additional distance would extend a round trip traverse from the South Pole to about nine days. To deliver all the cargo and equipment necessary in the time available, several more tractors would be needed. 2.2.2.3 Development of a compacted-snow runway at the South Pole Station A wheeled-aircraft runway at the South Pole Station would be the most desirable option from a logistics point of view. Because the South Pole is located in an area of snow accumulation, the runway would be prepared on compacted snow. About 20 cm of new snow accumulates at the South Pole each year. The runway, therefore, would have to be periodically replaced to accommodate the slowly rising snow surface. It may not be economically feasible to continue to resurface the runway after the major construction effort of replacing the South Pole Station is completed. The methods for constructing this type of runway are still experimental, and it is not certain that a runway capable of supporting C-130 aircraft can be built at the South Pole. The runway would probably be constructed using a device for disaggregating and adding energy to the snow, followed by a roller to compact the snow. A snow plane would be used to smooth the surface. Compaction would take place in layers to build up a snow pavement of the required thickness and support capabilities (Abele 1990). Mellor (1988) identifies several other compaction techniques, such as impact devices, sawdust or chemical additives, melt-freeze bonding by heating or wetting, and airfield mats. Extensive testing would be required to determine the strength of the runway surface and its ability to withstand wheeled aircraft landings. Maintenance of the runway would involve reconstruction of the runway surface layer every year. If such a runway were to prove successful, it would be supported by the South Pole Station personnel and facilities and the number of additional support personnel should be kept to a minimum. All vehicles except aircraft would be serviced and maintained at the South Pole Station. 2.2.2.3 No-action alternative Under the no-action alternative, no additional air logistics capabilities using wheeled aircraft would be added to support activities at the South Pole Station. This alternative would make reconstruction or replacement of the South Pole Station dependent on LC-130 support, airdrop, or traverse from McMurdo. Use of LC-130s would greatly reduce the support available for science during the construction period, and might significantly extend the time required to build the new station. 2.2.3 Other blue-ice runways for science support and enhancing safety Swithinbank (1991) reviewed approximately 27,000 aerial photographs of Antarctica for ice fields that might be suitable as sites for blue-ice runways. His analysis indicated that many of these areas appeared to be unsuitable for transport aircraft because of slope, grade change, length, crevasses, cross winds, or obstructed approaches. Swithinbank's study identified 84 potential blue-ice runway sites. A blue-ice area runway at Patriot Hills (80§19'S, 81§W), about 1,075 km from the South Pole, has been used by commercial adventure tour operators since 1987. In addition, Twin Otter landings have been made at the Mill Glacier and Mount Howe sites (Mellor and Swithinbank 1989). Surveys have been conducted at the Rosser Ridge site (82§46'S, 53§40'W) in the Pensacola Mountains and the Mount Lechner site (83§15'S, 51§14'W) in the Forrestal Range (Kovacs and Abele 1977, as cited in Mellor and Swithinbank 1989). Additional reconnaissance is planned of the Reedy Glacier site (85§45'S, 133§00'W) that might provide an advanced base for work on the Siple Coast and other parts of West Antarctica (Fig. 4). Another area that is of interest is an extensive area of blue ice in the Patauxent Range of the Pensacola Mountains (Fig. 4) that could provide an advance base of operations for work in the direction of the Weddell Sea and the Antarctic Peninsula. Areas of possible interest as emergency landing fields for conventional aircraft flying between McMurdo and New Zealand would be those within a 280-km radius northwest of McMurdo and a site at the Rennick Glacier (71§30'S, 162§15'E) (Fig. 4). 3. AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES 3.1 PEGASUS SITE 3.1.1 Affected Environment The Pegasus site (166§35'E, 78§S) is located about 13 km east of Williams Field on the Ross Ice Shelf (Figs. 2 and 3). The site is just within the accumulation zone of the ice shelf. The winds in the area are variable, and there are no rock exposures in the vicinity. No wildlife resources are present at the site itself, although skuas and other animals (for example, seals or penguins) occasionally do move into the area . White Island, a Site of Special Scientific Interest (SSSI), is approximately 15 km from the Pegasus site. McMurdo Sound lies approximately 13 km to the northwest and is an important area for marine mammals and birds. Weddell seals, Adelie penguins, and Emperor penguins use the area for breeding. Historically, seal and penguin populations have been affected by human populations in the McMurdo vicinity (for example, used as a food supply for dogs), but currently impacts are minimal and limited to scientific studies and the presence of humans in the area (NSF 1991). 3.1.2 Environmental Consequences of Developing a Runway at the Pegasus Site Construction and operational impacts of a blue-ice or compacted-snow runway at the Pegasus site are expected to be negligible. The area is approximately 13 km from McMurdo on the Ross Ice Shelf and does not provide habitat for any terrestrial or aquatic plant or animal life. Operation of construction equipment would result in small amounts of combustion products emitted to the atmosphere and small amounts of oil, lubricants, and fuel leaked onto the ice surface. A temporary building would provide shelter and office space for the construction crew, and additional moveable buildings would be located at the site once the runway was successfully tested to provide an emergency shelter, a heatable rest facility, and a toilet facility. Fuel spills could occur during refueling of aircraft and equipment at the site. In the early stages of operation, fuel would be transported to the site in small tanks mounted on sleds (Sect. 3.2.1). If operations increase, a large fuel storage tank would be moved to the site. Spills or leaks of oil, fuel, lubricants, and other fluids from aircraft, runway construction and maintenance equipment, vehicles to transport people and cargo, support buildings and facilities, and fuel storage sites would decrease the surface albedo and could result in deterioration of the snow and ice surface. To prevent surface deterioration and contamination of the environment, spills and leaks would be cleaned up as quickly as possible by using absorbants. Contaminated snow and ice would be scraped up, placed in containers, and transported to McMurdo for removal of contaminants, if feasible, and retrograding. Clean snow would be spread on affected areas to prevent further deterioration. Although the site does not support any wildlife populations that would be affected by construction or operation, Weddell seal populations occur at SSSI No. 18 on the north-west side of White Island and in the vicinity of Scott Base and McMurdo Station. Aircraft landing and taking off from the Pegasus site would be directed not to fly over SSSI No. 18 to avoid any disturbance to seal populations there. Wildlife in the vicinity of Scott Base and McMurdo have become accustomed to aircraft operations, and aircraft landings farther away at Pegasus are unlikely to disturb these populations. Atmospheric emissions from aircraft, support vehicles, and power generators at Pegasus would occur. Such emissions would be similar to, but less than, those presently generated at McMurdo and would be a very small addition to present emissions. No significant deterioration of air quality would be anticipated from construction and operation of the Pegasus site. Solid and liquid wastes produced at the site during construction and operation would be transported to McMurdo for appropriate disposal. Sanitary wastes would be collected in barrels that would be returned to McMurdo and emptied into the McMurdo wastewater system. Periodically, the site would be policed to remove trash, dunnage, and barrels. Pallet supports used for baggage and cargo would be returned to McMurdo for reuse. 3.1.3 Environmental Consequences of the No-Action Alternative at the Pegasus Site The no-action alternative would result in no development of a blue-ice or compacted-snow runway at the Pegasus site. Impacts of existing operations at the sea-ice runway and Williams Field are addressed in the SEIS (NSF 1991). If the Pegasus site is not developed, no additional activities would occur at the site, no impacts from future development activities would occur, and the existing test runways would quickly return to a natural state. Use of wheeled aircraft for re-deployment at the end of the season would not be possible, and the potential for extending the season would not exist. 3.2 MOUNT HOWE SITE AND MILL GLACIER SITES 3.2.1 Affected Environment Mount Howe (87:20'S, 149:50'W), located in the Transantarctic Mountains, is the closest blue-ice runway site to the South Pole (about 300 km) (Fig. 4). The site (elevation 2,400 m) is located immediately west of the Mount Howe ridge (elevation of peaks about 2,930 and 2,790 m) and associated moraines. The area of interest is relatively smooth and free of crevasses and snow drifts. It is about 7 km long, running in a NNE-SSW direction, and its width, which is limited by crevasses to the west, ranges from about 2-3 km. The prevailing winds are from the mountain ridge. An Automated Weather Station was installed at the site during the 1991-92 season. The area supports no plants or animals. The Mill Glacier site (85:06'S, 167:15'E) is a blue-ice area located near Plunket Point in the Transantarctic Mountains about 540 km from the South Pole (Fig. 4). Mill Glacier is a valley glacier that flows down from the Grosvenor Mountains, past the Otway Masif, and down between the Dominion Range and the Supporters Range, joining the Beardmore Glacier near Plunket Point. The site is at an elevation of about 1,800 m and is bounded on the west by the Meyer Desert, an ice-free rock massif, and on the east by giant rifts in the glacier surface (Mellor and Swithinbank 1989). The crevasse-free area within which an airfield could be located is more than 7 km long, running in a NNW-SSE direction, and varies in width from 1 km at the northern end to 100 m at the southern end. The wind direction appears to be 160§ true. The site does not support any animal or plant life. 3.2.2 Environmental Consequences of Developing Blue-Ice Runways Impacts of developing a blue-ice runway at Mount Howe or Mill Glacier would be similar to those of developing a blue-ice runway at the Pegasus site. Because these two sites are located on the Polar Plateau, no plant or animal life would be affected by construction or operation activities. Spills or leaks of oil, fuel, lubricants, and other fluids from aircraft; runway construction and maintenance equipment; vehicles to transport people and cargo; support buildings and facilities; and, fuel storage sites could result in deterioration of the ice surface. These spills or leaks would be cleaned up in a manner similar to that described in Sect. 5.1.1. Such cleanup would be faster and much easier because spilled fluids would not soak into porous snow but rather would remain on the ice surface. Impacts of atmospheric emissions from aircraft and equipment are expected to be negligible because of the small number of flights, the limited size of the support facilities, and the remote location. Some deterioration of the pristine environment immediately surrounding these sites would result, but in general the impact would be less than minor or transitory (that is, of no significance). Solid, liquid, and sanitary wastes would be collected and returned to McMurdo for appropriate disposal. Development of blue-ice runways at these sites would also involve development of traverse routes to the South Pole Station. Environmental impacts of these traverse routes are not assessed in this IEE, but they will be assessed in environmental documentation prepared for any rebuilding or replacement of the South Pole Station. Development of these runways would indirectly impact the South Pole Station because of the need for increased personnel and support needed at the South Pole during initial construction and annual rebuilding of the runway. 3.2.3 Environmental Consequences of the No-Action Alternative If blue-ice runways were not developed at Mount Howe or Mill Glacier, no additional environmental impacts would occur from USAP activities at these sites. No buildings would be located at the sites, and human presence at the sites would not increase. Mill Glacier has already been used for landings and may continue to be used for such purposes in the future. However, the site would not be developed for providing support to the South Pole and future use is likely to be restricted to support for field camps. 3.3 SOUTH POLE STATION 3.3.1 Affected Environment The South Pole Station is located on the Polar Plateau at an elevation of 2,900 m. The high plateau causes persistent and predictable winds to blow downslope toward the perimeter of the continent. The circulation of coastal storms affects surface winds at the South Pole infrequently. Consequently, peak winds at the South Pole are quite low in comparison with those in coastal areas of Antarctica. Temperatures measured at the South Pole have ranged from a minimum of -80.6§C to a maximum of - 13.6§C. The mean monthly temperatures range from about -60§C in July and August to about -28§C in December and January. The mean annual temperature is -49.3§C (Schwerdtfeger 1984). Precipitation at the South Pole is either light snow or, more frequently, ice crystals. The estimated annual average accumulation is 7 cm of water equivalent (Schwerdtfeger 1984). Snow is lost only by ablation or blowing toward the edge of the continent. Snow has accumulated and formed an ice cap over the continent about 2,850 m thick. This ice sheet moves about 10 m/year toward the Weddell Sea (Giovinetto and Bentley 1985). The South Pole site includes the current station completed in 1975 and former facilities now covered by snow. Because the South Pole Station is located on the high-altitude, inland plateau, there are no aquatic or terrestrial ecological resources. 3.3.2 Environmental Consequences of Developing a Compacted-Snow Runway Construction of a compacted-snow runway is expected to have only "minor or transitory" (that is, no significant) environmental impacts. Additional personnel and specialized equipment would be required to prepare the runway because maintenance of the existing skiway would continue to be needed. Operation of a compacted-snow runway would result in similar impacts to those experienced with the existing skiway. Spills and leaks of oil, fuel, lubricants, and other fluids from aircraft, runway construction and maintenance equipment, and fuel storage sites could result in deterioration of the compacted-snow surface and would be cleaned up to the extent possible. To avoid or minimize impacts from contaminated snow materials, NSF would instruct its contractor to collect and process contaminated snow materials to remove contaminants. Contaminated materials would then be transported to McMurdo for appropriate retrograde from Antarctica. Assuming that the present level of scientific research would be maintained during any construction activities at the South Pole Station, a greater number of flights would occur involving a combination of ski-equipped LC-130 and wheeled C-130 aircraft. As a result of more flights, there would be a higher level of atmospheric emissions from aircraft during this period. Impacts from aircraft emissions have been discussed in the SEIS (NSF 1991), and the increased level of flights that would result from any construction activities at South Pole would not add a sufficient increment of emissions to cause a significant impact. Development of a compacted-snow runway at the South Pole Station would be a net beneficial impact during any rebuilding project because wheeled aircraft could be used, at least in part, to support science at the South Pole and provide, therefore, more efficient operation, fewer flights to deliver the same amount of cargo, and less fuel used. Long-term development of a runway for wheeled aircraft may not be economically feasible after any rebuilding project has been completed. 3.3.3 Environmental Consequences of the No-Action Alternative Under the no-action alternative, any reconstruction of the South Pole Station would be dependent on using LC-130s to transport construction materials and equipment or other alternatives such as overland traverse or airdrops. Environmental impacts of using LC-130s would be similar to those from existing operations (NSF 1991). Because of the limited cargo capability of the LC-130s, any construction period would have to be extended. Use of LC-130s to transport construction materials, equipment, and personnel would greatly limit the available support for science and would have a significant adverse impact on the science program. Use of airdrops would increase the cost of transport. Overland traverse of materials from McMurdo is possible, but very expensive, and it would involve an extended risk to the safety and health of personnel involved with the traverse. 3.4 OTHER POTENTIAL BLUE-ICE RUNWAY SITES 3.4.1 Affected Environment Very little is known about most of the 84 potential airfield sites identified by Swithinbank (1991) (Sect. 3.2.3). In most cases, no one has ever visited the sites identified from the aerial photographs. One important exception is the Patriot Hills blue-ice site that is located to the north of the isolated Patriot Hills ridge in the Ellsworth Mountains (Fig. 4). The ice field covers a 2 km x 8 km area and is low in elevation (750 m) relative to Mount Howe and Mill Glacier. The site has been used for wheel landings of DC-4 aircraft, and temporary camps capable of housing up to 40 people have been maintained during the summer months on the moraine at Patriot Hills (Mellor and Swithinbank 1989). Currently, the site is used for wheel landings of DC-6 tourism aircraft (Swithinbank 1991). 3.4.2 Environmental Consequences of Developing Other Blue-Ice Runways Blue-ice runways could be developed at other locations in Antarctica to support scientific activities (Sect. 3.2.3). If such runways were constructed, impacts resulting from construction would be similar to those discussed for Mount Howe and Mill Glacier and would be less than minor or transitory in nature (that is, of no significant impact). Impacts of using such runways would be similar to those that occur for current LC-130 skiways that are used to support field science parties as discussed in the SEIS (NSF 1991). Should a major field base be developed associated with such a runway, additional environmental documentation would be prepared. 3.4.3 Environmental Consequences of the No-Action Alternative If no additional blue-ice runways are developed, there should be no new environmental impacts associated with runway development. LC-130s and Twin-Otter type aircraft would continue to be used and landings would be made on snow and ice surfaces and existing skiways. 3.5 CUMULATIVE ENVIRONMENTAL IMPACTS Cumulative environmental impacts from the USAP developing blue-ice and compacted-snow runways in Antarctica could occur if the numbers of aircraft and flights to and on the continent increased. Increased use of aircraft would result in increased emissions of atmospheric pollutants from aircraft engines and from maintenance equipment and support activities. Additional personnel would be required to maintain and operate aircraft and to handle cargo carried by these planes. More fuel would be required, and the risk of fuel spills and leakage of fuel, oil, and lubricants would increase in proportion to the number of flights added. These cumulative impacts can be minimized with appropriate planning. Use of wheeled aircraft for transporting cargo and passengers is more efficient than use of the ski-equipped LC-130s. C-130s and C-141s use fuel more efficiently, and fewer flights would be required to transport equivalent amounts of cargo and passengers. To meet the USAP goal of reducing the overall environmental impacts of the program on Antarctica (Sect. 1), it may be necessary to reduce other support activities and possibly science programs during periods of peak construction activity. 4. FINDINGS The proposed development of blue-ice and compacted-snow runways to enhance the use of wheeled aircraft by the USAP would cause less than minor or transitory environmental impacts (that is, no significant impacts) and could contribute to the program's goal of reducing human impacts to the Antarctic environment. Adverse environmental impacts that could result from the development and subsequent use of blue-ice and compacted-snow runways include contamination of ice and snow from spills or leaks of fuel, oil, and lubricants, contamination of pristine areas by atmospheric emissions from aircraft and equipment used for construction and maintenance of the runway, disturbance of sensitive wildlife resources by low-flying aircraft, and degradation of the aesthetic environment associated with remote sites where such runways would be located. Use of wheeled aircraft could result in reducing the number of flights required to support USAP activities on the continent that would in turn have the environmental benefits of reduced fuel use and emissions, fewer support personnel needed for operation and maintenance, and greater flexibility for scheduling science activities that could reduce the numbers of support personnel required at peak seasons of the year. USAP is proposing to develop a compacted-snow or blue-ice runway on an ice shelf at the Pegasus site near McMurdo Station and is evaluating the remote possibility of developing (1): a blue-ice runway at Mount Howe; (2) expanding the use of the runway at Mill Glacier; or, (3) developing a compacted-snow runway at the South Pole to transport construction materials and equipment for any rebuilding the South Pole Station. In addition, blue-ice runways may be developed elsewhere in Antarctica to support scientific activities and field camps. Potential adverse impacts at all of these sites would be less than minor or transitory in nature (that is, they would pose no significant impacts). Fuel spills and leaks would be cleaned up to the extent practicable and all contaminants removed from the snow and ice would be returned to McMurdo for retrograde from Antarctica. Solid, liquid and sanitary wastes would be placed in containers and returned to McMurdo for disposal. Atmospheric emissions would be released from aircraft, construction and maintenance equipment, and power generators; the degree to which these emissions would degrade local air quality is anticipated to be both less than minor and transitory (that is, they would pose no significant impacts). The number of flights that would use these runways is not yet determined; but, no significant degradation of air quality is anticipated from aircraft operations. The only wildlife populations that could possibly be affected by development of blue-ice or compacted-snow runways are seal and penguin populations in the general vicinity of the Pegasus site. Normal landing and takeoff patterns would avoid the SSSI site on White Island, and no adverse impacts to seals and penguins from low-flying aircraft in the immediate vicinity of McMurdo Station and Scott Base are anticipated because populations in this area are acclimatized to aircraft operations. Some degradation of the aesthetic environment at blue-ice and compacted- snow runways is unavoidable because of the presence of aircraft, people, construction and maintenance equipment, and structures. At the Pegasus site, this change in aesthetics could be relatively permanent if the runway proves to be successful. A compacted-snow runway at the South Pole Station should have essentially no aesthetic impact as it would require no additional support structures and would be compatible with the existing skiway and station. The aesthetic intrusion of blue-ice runways at other sites in Antarctica is expected to be both less than minor and transitory (that is, of no significant aesthetic impact). In some cases, temporary buildings may be located at such a site for a few years. Because many of these runways require minimal surface preparation, there is little visual intrusion. Aircraft are present at these sites only for short periods of time, and construction and maintenance equipment would be limited and removed when the activity is over. The findings of this IEE are that development and subsequent use of blue-ice and compacted-snow runways would have less than minor or transitory environmental impacts (that is, no significant environmental impacts are anticipated) and could benefit the program. The benefits of developing such runways could include using wheeled aircraft to transport personnel to New Zealand at the end of each austral summer research season, thereby making more LC-130s available to support science during this time; possibly extending extend the austral summer research season or allowing year-round access to McMurdo; being able to transport equipment and supplies to the South Pole more efficiently; providing access to sites that could be used as base camps for major science projects; and, improving safety of antarctic operations. Greater use of wheeled aircraft would improve the efficiency of support operations because they carry more cargo and use less fuel. Such increases in efficiency could reduce the number of flights needed and could, in turn, reduce the number of support personnel that need to be sent to Antarctica. 5. LITERATURE CITED Abele, G. 1989. Snow Roads and Runways. Monograph 90-3. U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire. Antarctic Treaty Consultative Parties. 1991. Protocol on Environmental Protection to the Antarctic Treaty. XI Antarctic Treaty System Consultative Meeting/2/3/2. Madrid, Spain (October 3-4, 1991). Blaisdell, G. L., V. Klokov, and D. Diemand. 1992. Development of a wheeled Runway for McMurdo on the Ross Ice Shelf. Paper presented at the XXII SCAR Meeting, San Carlos de Bariloche, Argentina, June 1992. Draggan, S., and P. Wilkniss. 1993. An Operating Philosophy for the U.S. Antarctic Program. Marine Pollution Bulletin 25 (9- 12): in press. Giovinetto, M. B., and C. R. Bentley. 1985. "Surface balance in ice drainage systems of Antarctica." Antarctic Journal of the United States 24(4):6-13. Kovacs, A., and G. Abele. 1977. Runway site survey, Pensacola Mountains, Antarctica. CRREL Special Report 77-14. Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire. Mellor, M. 1988. Hard Surface Runways in Antarctica. CRREL Report SR88-13. U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire. Mellor, M. and C. Swithinbank. 1989. Airfields on Antarctic Glacier Ice. CRREL Report 89-21. U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire. National Science Foundation. 1990. Environmental Action Memorandum on the Installation of an Experimental Runway at the Pegasus Site. Division of Polar Programs, Washington, D.C. (October 3). National Science Foundation. 1991. Final Supplemental Environmental Impact Statement on the U.S. Antarctic Program. Division of Polar Programs, Washington, D.C. (October). Schwerdtfeger, W. 1984. Weather and Climate of Antarctica. Elsevier Science Publishing Co., New York, NY. Swithinbank, C. 1989. Ice Runways Near the South Pole. Special Report 89-19. U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire. Swithinbank, C. 1991. Potential Airfields Sites in Antarctica for Wheeled Aircraft. CRREL Report 91-24. U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire. USAP Safety Review Panel 1988. Safety in Antarctica. National Science Foundation, Washington, D.C. 6. LIST OF PREPARERS NATIONAL SCIENCE FOUNDATION, OFFICE OF POLAR PROGRAMS PANEL Dr. Sidney Draggan, Panel Chairperson Dr. Jane Dionne, Co-Chairperson Dr. Peter E. Wilkniss Mr. Erick Chiang Mr. Dwight D. Fisher COLD REGIONS RESEARCH LABORATORY Mr. George L. Blaisdell Mr. Stephen L. DenHartog Mr. Wayne Tobiasson OAK RIDGE NATIONAL LABORATORY Assessment Support:: Dr. Robert M. Reed Mr. Lance B. McCold Mr. J. T. Ensminger Dr. J. Warren Webb Dr. Richard B. McLean Mr. Jeremy Holman FIGURES