McMurdo Station is an American Antarctic research station on the southern tip of Ross Island. It is operated by the United States through the United States Antarctic Program (USAP), a branch of the National Science Foundation (NSF). The station is the largest community in Antarctica, capable of supporting up to 1,200 residents, though the population fluctuates seasonally; during the Antarctic night, there are fewer than two hundred people. It serves as one of three year-round United States Antarctic science facilities. Personnel and cargo going to or coming from Amundsen–Scott South Pole Station usually first pass through McMurdo, either by flight or by the McMurdo to South Pole Traverse; it is a hub for activities and science projects in Antarctica. McMurdo, Amundsen-Scott, and Palmer are the three non-seasonal United States stations on the continent, though by the Antarctic Treaty System the bases are not a legal claim (though the right is not forfeited); they are dedicated to scientific research. New Zealand's Scott Base is nearby on Hut Point Peninsula, as is Arrival Heights Laboratory. On the base is a heliport, and across the channel is a helicopter refueling station at Marble Point, but the main airfields in the 2020s are Phoenix Airfield and Williams Field which are to the south and built on ice. Winter Quarters Bay is the base seaport, though access can be limited by weather conditions when the sea ice forms. Weather can make it too hard to land aircraft, and an icebreaker may be needed to reach the port facility. However, the sea ice also makes it possible to make ice traverses and travel directly across the bay, and historically an Ice Runway was crafted. The base is powered by a mixture of generators and wind power, though it had a nuclear reactor in the 1960s.

The base was first established in the mid-1950s as part of an international program to study and explore Antarctica for peaceful purposes. Daylight is seasonal at McMurdo, corresponding to the south polar summer, and the polar night, which is also winter, lasts from about April to September. As it warms, the sea ice melts, and the port is opened, but by about February, much of the activity drops with plunging temperatures and increasing darkness, and there are usually no flights in or out until July or August.

The base has many buildings and staff which support the local population and its many field stations and research projects. The base is the starting point for the South Pole Traverse snow and ice road, which must be cleared each year, as do the snow and ice runways. The base is distant from New Zealand, about the same distance as between New York and Los Angeles, or as between Los Angeles and Hawaii. Some of the projects and/or field stations McMurdo Station has supported include the Lower Erebus Hut, for the study of Mount Erebus (an active volcano to the north of the base), WAIS Divide Camp (an ice coring project), ANDRILL (ANtarctic DRILLing Project), ANSMET (meteorite collection), and the Long Duration Balloon site. Telecommunication sites include Ross Island Earth Station, Black Island Earth Station, and the NASA Ground Station. The Amundsen–Scott South Pole Station is supported primarily through the McMurdo Station, and resources to many international camps also come through McMurdo and its facilities.

History McMurdo started in December 1955, and was established in 1956 as a Naval Air Station in support of the International Geophysical Year, then as a science and logistics base in line with the international Antarctic treaty. Each year there are changes at the base, but the overall rhythm of the base has remained. Supplies and people flow in by ship and air for the austral summer, and for a few months there is a frenzy of activities, research, and resources flow out to many field stations and bases in Antarctica. In a few months people depart as the temperature plunges and worsening weather conditions, and much smaller staff over-winter at the base. Originally a Naval base, the role of the NSF and contractors increased and by 1993 the USN had departed. The NSF collaborates with other agencies including the U.S. Coast Guard, US Air Force, New Zealand Air Force, and NASA, as well as many academic institutions.

Name

The station takes its name from its geographic location on McMurdo Sound, named after Lieutenant Archibald McMurdo of British ship . The Terror, commanded by Irish explorer Francis Crozier, along with expedition flagship Erebus under command of English Explorer James Clark Ross, first charted the area in 1841. The British explorer Robert Falcon Scott established a base camp close to this spot in 1902 and built a cabin there that was named Discovery Hut. It still stands as a historic monument near the water's edge on Hut Point at McMurdo Station. The volcanic rock of the site is the southernmost bare ground accessible by ship in the world. The United States officially opened its first station at McMurdo on February 16, 1956, as part of Operation Deep Freeze. The base, built by the U.S. Navy Seabees, was initially designated Naval Air Facility McMurdo. On November 28, 1957, Admiral George J. Dufek visited McMurdo with a U.S. congressional delegation for a change-of-command ceremony.

In 1961, it was renamed from Naval Air Facility McMurdo, to just McMurdo. The Navy would be involved until 1993, when it left McMurdo in the hands of the NSF. The NSF had been involved over the decades and took on greater responsibilities over the years.

International Geophysical Year

McMurdo Station was the center of United States logistical operations during the International Geophysical Year, an international scientific effort that lasted from July 1, 1957, to December 31, 1958. After the IGY, it became the center for US scientific as well as logistical activities in Antarctica. The IGY was an international project in the late 1950s by 67 countries and involved over 4,000 research stations Globally.

McMurdo was one of seven bases that the United States built for the IGY, which also included Hallett, Wilkes, Admundsen-Scott, Ellsworth, Byrd, and Little America. Of these only McMurdo and Admundsen-Scott are still operated in the early 21st century.

As part of this endeavour, New Zealand also built a base on Ross Island, Scott Base, which has gone on to conduct many scientific projects. Scott Base is still in operation, but a second year-round New Zealand base, Vanda Station, built later on the Antarctic mainland, has since closed; it still has a weather station and is visited seasonally. Also, Hallet Station was a joint base of New Zealand and the US, which was operated until 1973.

Antarctica Treaty

The Antarctic Treaty, subsequently signed by dozens of governments, regulates intergovernmental relations with respect to Antarctica and governs the conduct of daily life at McMurdo for United States Antarctic Program (USAP) participants. The Antarctic Treaty and related agreements, collectively called the Antarctic Treaty System (ATS), opened for signature on December 1, 1959, and officially entered into force on June 23, 1961.

On the heels of the success of the IGY, the treaty was developed with three major points, to continue Antarctica's legal status, to use it for scientific purposes, and for peaceful purposes.

1960s and 70s In 1960, one of the longest-running science experiments at McMurdo was established, the CosRay detector. This detected energetic particles from the Sun, and would operate until 2016 when it was moved to the nearby Jang Bogo station.

In 1961 the Antarctic Treaty System entered into force and the base was renamed McMurdo Station.

The first scientific diving protocols were established before 1960 and the first diving operations were documented in November 1961.

From 1961 to 1972, McMurdo Station relied on a small PM-3A nuclear reactor for power, which also provided heat for a desalination plant that produced fresh water from seawater. The reactor-powered plant could generate approximately 14,000 gallons of water per day. The reactor could produce 1.8 megawatts of power and would enable a reduction in fuel oil shipments. In the 1950s, fuel oil was about half the weight of all cargo going to Antarctica, and there was other expected benefits. The oil heaters being used to heat buildings were a fire safety hazard, and there was a demand for reliable power over the dark winter months when the station could not be resupplied.

The nuclear plant was brought to the base in December 1961, and produced electricity on July 10, 1962. The reactor was modular, and could be broken into sections small enough for a C-130 even though it was brought to McMurdo by ship. The reactor proved expensive to operate, and was turned off over concerns of stress corrosion.

In 1973 the Thiel Earth Science Laboratory (TESL) was dedicated, named after the geologist Edward Thiel. He died in 1961 in a plane that crashed trying to take off from Wilkes Station. The Thiel Laboratory later became office for Field Training Safety in the 1990s, after its work moved to the Crary lab.

Between 1962 and 1963, 28 Arcas sounding rockets were launched from McMurdo Station, collecting the first measurements above radiosonde levels of altitude in Antarctica

In 1967, the first Winter fly-in (WinFly) took place in June and August, providing a supply and personnel relief for those overwintering at McMurdo, reducing the duration of their isolation to about 4–5 months. This marked the first phase of Operation Deep Freeze, aimed at resupplying McMurdo and supporting the busy austral summer season.

In 1974, Mary Alice McWhinnie and Mary Odile Cahoon became the first women to winter over at McMurdo Station, staying from April through October of that year. In 1962 McWhinnie became the first female in the Antarctic Research Program.

1980s In 1982 new generators were installed; this included six diesel generators that could produce 900 kilowatts each, though the number used depends on base population. It also powers the desalination plant and waste heat, heats the buildings at McMurdo.

In the late 1980s, construction started on what would be the new Crary science laboratory, a larger and connected facility that would replace some of the older labs.

In 1989, a Greenhouse for McMurdo was built, which could supply a limited supply of fresh greens year round. A new chapel was dedicated in 1989 after the previous had burned down in 1978. A temporary chapel in a quonset hut was used in the interim, though that also burned later in 1991. During this period, a number of social establishments were open, many of which were organized according to military rank. While civilians were permitted to enter any of these venues, access for military personnel was typically segregated by rank.

In the 1988-89 season a hovercraft was tested. These hovercraft could traverse over land, ice, water, and melting sea ice mixture. The design was relatively easy to use, and the McMurdo kitchen staff were test drivers after some training.

1990s

The 1990s marked a period of transition for McMurdo Station, highlighted by the withdrawal of the United States Navy, which had played a central role in the station's governance and operations since its founding. Over the preceding decades, the National Science Foundation (NSF) had gradually assumed greater responsibility and was ultimately designated as the lead agency. The NSF continued to coordinate with other entities, including the United States Coast Guard, the Air Force, NASA, and various civilian contractors.

In 1990, one area of study was the ozone layer. In particular, there was concern over ozone depletion, and measurements of this layer were taken in 1990 from McMurdo.

In December 1991, the new Crary lab, named for Albert P. Crary, was dedicated, replacing the older Thiel Earth Science Laboratory and the Eklund Biological Center.