Amundsen-Scott South Pole Station

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Image:04overall.jpg The Amundsen-Scott South Pole Station is an American research station at Earth's South Pole in Antarctica. This makes it the southernmost continually inhabited place on the planet. The station's name honors Roald Amundsen and Robert F. Scott, who attained the South Pole in 1911 and 1912.

The station was originally constructed in November 1956 to support the International Geophysical Year in 1957, and has been continuously occupied since then. It currently lies within 100 meters (330 feet) from the Geographic South Pole, and drifts towards the pole at the rate of about 10 meters per year.

Recorded temperature has varied between −13.6 °C (7.52 °F) and −82.8 °C (−117 °F). Annual mean is −49 °C (−56.2 °F); monthly means vary from −28 °C (−18.4 °F) in December to −60 °C (−76 °F) in July. Average wind is 5.5 m/s (12 mph); peak gust recorded was 24 m/s (54 mph).

Snow accumulation is about 6–8 centimeters (water equivalent) per year (3 in/yr). The station stands at an elevation of 2,835 meters (9,301 ft) on interior Antarctica's nearly featureless ice sheet, about 2,850 meters (9,350 ft) thick at that location.

1 Facility History
2 Operation
3 Media and events
4 Time zone
5 See also
6 External links

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Facility History

Although the US has continuously maintained an installation at the South Pole since 1957, the central berthing, galley, and communications units have been constructed and relocated several times. Each of the installations containing these central units was named the Amundsen-Scott South Pole Station.

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Original station (1957–1975)

The original South Pole station, now referred to as "Old Pole", was constructed by an eighteen man Navy crew during 1956–1957. The crew landed on site in October 1956 and was subsequently the first group to winter-over at the South Pole during 1957. Since the winter conditions at the South Pole had never been measured, the station was built partially underground in order to protect it from the worst imaginable weather. The worst conditions turned out to be "mild". The low temperature during 1957 was −74 °C (−102 °F) which combined with low humidity and low air pressure is manageable with proper protection.

As with all structures at the South Pole, the original station caused wind blown snow to build up in the surrounding area. This snow accumulation resulted in the structure being further buried by about four feet of snow per year. The station, abandoned since 1975, is now deeply buried in snow and the pressure has caused the mostly wooden roof to cave in. The site is therefore a hazardous area and off limits to all South Pole visitors.

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Dome (1975–?)

Image:Pole-from-air.jpg Image:Amundsen-Scott South Pole Station.jpg

The station was relocated and rebuilt in 1975 as a geodesic dome 50 meters wide and 16 meters high that, with 14 m × 24 m steel archways, covers modular buildings, fuel bladders, and equipment. Detached buildings within the dome house instruments for monitoring the upper and lower atmosphere and for numerous and complex projects in astronomy and astrophysics. The station also included the skylab, which is a box shaped tower slightly taller than the dome and accessible by tunnel. The skylab housed atmospheric sensor equipment and later a music room.

During the 1970-1974 summers, the dome construction workers were housed in Korean war tents or "jamesways". These tents consist of a wooden frame with a raised platform covered by canvas. A double doored exit is located at each end of the tents. Although the tents are heated, the heating power is not sufficient to keep them room temperature during the winter. After several jamesways burnt down during the 1976-1977 summer, the construction camp was abandoned and later removed.

However starting in the 1981-1982 summer, extra seasonal personnel have been housed in a group of jamesways known as "summer camp". Initially consisting of only two jamesways, summer camp now has 11 berthing tents (housing about 10 people each), two recreational tents as well as bathroom and gym structures. In addition, a number of science and berthing structures (such as the hypertats and elevated dorm) were added in the 1990s, particularly for astronomy and astrophysics.

During the period in which the dome served as the main station many changes to US South Pole operation took place. From the 1990s on, astrophysical research conducted at the South Pole took advantage of its favorable atmospheric conditions and began to produce important scientific results. Such experiments include the Python, Viper, and DASI telescopes as well as the planned 10 m South Pole Telescope. The AMANDA / IceCube experiment makes use of the two-mile-thick ice sheet to detect neutrinos which have passed through the Earth. The importance of these projects changed the priorities in station operation, increasing the status of scientific cargo and personnel.

The 1998/1999 summer season was the last year that the US Navy operated the five to six LC-130 Hercules service fleet. Beginning in 1999/2000, the New York Air National Guard's 109th Airlift Wing took responsibility for the daily cargo and passenger ("PAX") flights between McMurdo Station and the South Pole during the summer.

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Elevated station (2003–?)

Image:Amundsen-Scott marsstation ray h edit.jpg Construction on a new station, adjacent to the Dome, began in 1999. Features of the new station included a modular design, to accommodate an increasing station population, and an adjustable elevation, in order to prevent the station from being buried in snow drift. The building is situated so that it faces into the wind with a sloping lower portion of wall. This angled wall increases the speed of the wind as it passes underneath the facility, causing the snow to be scoured away and keeping the building from being quickly buried below the snow. Wind tunnel tests show that scouring will continue to occur until the snow level reaches the second floor of the facility.

In a location that receives about 20 cm (8 inches) of snow every year without ever thawing, the building's rounded corners and edges help reduce snow drifts. Because snow gradually settles over time, even under its own weight, the foundation of the building was designed to accommodate substantial differential settlements over any one wing, any one line, or any one column. If differential settlement continues, the supported structure will need to be jacked and leveled.

The facility was designed to be jacked up an entire story, so the primary building columns are outboard of the walls. During jacking, a new height of column will be added over the existing columns, and jacks will pull the building up to the higher elevation.

BBFM Engineers ( http://www.bbfm.com ) provided the structural engineering expertise for this project. Based in Anchorage, Alaska, this firm was selected in part because of its extensive work with structures in extremely cold conditions.

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Operation

Image:South Pole cargo.jpg During the summer the station population is typically over 200. Most personnel leave by the middle of February, leaving several dozen (127 in 2005) "winter-overs", mostly support staff plus a few scientists, who keep the station functional through the months of Antarctic night. The station's winter personnel are isolated between mid-February and late October. Wintering-over at the station offers notorious dangers and stresses, as the station population is almost totally isolated. The station is completely self-sufficient, and powered by three generators running on jet fuel.

Between October and February, there are several flights per day of ski-equipped LC-130 Hercules aircraft between McMurdo and the pole to supply the station.

Research at the station includes glaciology, geophysics, meteorology, upper atmosphere physics, astronomy, astrophysics, and biomedical studies. Most of the scientists work in low-frequency astronomy; the low moisture content of the polar air, combined with the altitude of over 2743 m (9,000 feet), causes the air to be far more transparent on some frequencies than is typical for most of Earth, and the months of darkness permit sensitive equipment to run constantly.

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Media and events

In 1999, the winter-over physician, Dr. Jerri Nielsen discovered she had breast cancer. She had to rely on self-administered chemotherapy using supplies from a daring July cargo drop, then was picked up in an equally dangerous mid-October landing.

The station has featured prominently in several science fiction television series, including The X-Files movie Fight the Future and the Stargate Atlantis series premiere "Rising". A South Pole station called Snowcap Base was the site of the first Cybermen invasion of earth in the 1966 Doctor Who serial The Tenth Planet.

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Time zone

The South Pole sees the sun rise and set only once a year, technically on the Vernal equinox in September and the Autumnal equinox in March respectively, but due to atmospheric refraction the site sees the sun above the horizon for some 4 days longer at each equinox. However the station uses the standard time of New Zealand (UTC+12, or UTC+13 during daylight saving time) since all flights to McMurdo station depart from Christchurch and therefore all official travel from the pole goes through that country.

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