A Brief History of the Apia Observatory  

Excerpts from “History of the Samoan Observatory from 1902 to 1921”, by G.H. Angenheister and "Apia Observatory 1902-1977", by Jack Hoffman. 

 In the year 1898 the Institute for Geophysics was founded at the Georg-August University at Göttingen. Shortly afterwards the Royal Prussian Society for Sciences of Göttingen* formed a Geophysical Commission, to which were attached: geophysicist, Emil Wierchert; mathematician, Felix Klein; physicist, E Reike, Waldemar Voight, and Walter Nernst; geologist, A. von Könen; geographer, Hermann Wagner; astronomer, W. Schur. In May 1900 at the joint meeting of the four German academies in Vienna, the delegates of the KPGW put forward the proposal to operate temporary seismic stations outside Europe. Sites discussed were Palestine, Kiaochow, South America, and Samoa for the Pacific.

 At the same time the German South-Polar Expedition was being prepared. At a meeting in November1899 of the Council entrusted with the preparation, the geomagnetician Adolf Schmidt had proposed that a station for recording the time variations of the Earth’s magnetic field should be set up in Samoa. This station would record data over a year at the same time as the other stations set up by the South-Polar Expedition in Antarctica. On the initiative of the above-mentioned Geophysical Commission, and especially of the geographer Hermann Wagner, the KPGW produced in April 24th 1901 a memorandum entitled: “Memorandum concerning the establishment of a temporary station for the geophysical observations in Samoa."

German installation

On the 11th of June 1902, Dr Otto Tetens began construction of a number of buildings for the geophysical observatory at Mulinu'u on the island of Upolu in Western Samoa. In August 1901, Kaiser Wilhelm II of Germany had granted a sum of 30,000 marks to the University of Göttingen to establish the observatory and in December of that year Dr. Tetens was selected as Director. As usual, costs of the establishment of the observatory were greater than expected and were relieved only in June 1905 when the German Treasury granted a sum of 25,000 marks annually for five years.

Meteorological instruments and Wierchert seismographs were installed in 1902 and the magnetic instruments added in 1905. The Gauss Haus and absolute house were built in 1912 and the main office buildings in 1913. Some of these buildings function for their original purpose today. German scientists who held the position as Director during the first decade included Drs. O. Tetens, F. Linke, G. Angenheister and K. Wegener. Angenheister remained for a second term from 1912 - 1920 and despite the First World War retained the directorship of the observatory known at that time as the Samoan Observatory. Angenheister then returned to Germany where he wrote the results of his observations during his latter term.

The fields of study at this period were geomagnetism, seismology, meteorology and atmospheric electricity. A requirement of such programmes is an accurate time service. The original master clock was a Strass and Rorde which is still in operation with an accuracy of about a fifth of a second a day. Time control was carried out by transit of the sun on a Heyde transit telescope.

In July 1976 the electronic time service (Time Signal Generator) with an accuracy of about a tenth of a second a day was installed to replace the clock system. The time control is derived from signals transmitted by the stations WWNH, Honolulu.

The magnetic variometers were Eschenhagen. For measuring D and H various magnetometers were used including a Tesdorf (1921 - 1936) and CIW instruments No. 5 (before 1921) and No. 9 (1936 - 66); a Schultze (No. 2) earth inductor has been used throughout and to the present day for measuring magnetic dip. Wiechert  seismographs with masses of 100 kgm in the horizontal plane and 80 kgm in the vertical plane provided the first good seismograph station in the Southern Hemisphere. The meteorological instruments were mainly of German origin except for a Robinson cup anemometer and a Campbell Stokes sunshine recorder. A Banndorf self-recording electrometer recorded the atmosphere potential gradient.

New Zealand Control

In 1921 the Observatory was formally taken over by the New Zealand Government, with its control vested in an Honorary Board of Advice acting for the Department of External Affairs. Administrative control was transferred to the New Zealand Department of Scientific and Industrial Research in 1928. In the interval between the wars, annual grants were made by the Department of Terrestrial Magnetism of the Carnegie Institute of Washington and the British Admiralty, although New Zealand met the greater share of the cost. New Zealand directors during this period, which ended in 1948, were Messrs C.J. Westland, A. Thomsen, J. Wadsworth and J.W. Beagley.

Pilot balloons for upper winds were first released in 1925. The lagoonal station for atmospheric electricity was also built in 1923 and a tidal gauge recorder supplied by the U.S. Coast and Geodetic Survey was installed in the lagoon in 1924; this tide gauge is still in operation and can be seen from the Observatory. In 1926 weather reporting commenced at Fakaofa and in the same year apparatus for measuring solar radiation was installed. In 1932 a spectro-helioscope was loaned by the Mount Wilson Observatory. In 1927 a Dines anemometer replaced the Robinson anemometer and was itself replaced in 1936 by a Pressure Tube Anemometer which was operated continuously until the early 90s when severe damages sustained during tropical cyclones Ofa & Val rendered it out of service.

Before the World War II, Apia Observatory became a forecasting center collecting reports from most major island ports and issuing hurricane and storm warnings. This became the Observatory's major contribution to the war effort in the Pacific theater. The New Zealand Meteorological Service had at this stage assumed the responsibility  for the meteorological programme and the Department of the Scientific Industrial Research retained the control of the seismological and geomagnetic programme.

In 1949, the Apia Observatory came under the control of the Geophysical Observatory, Christchurch, and the senior officer became known as the Observer-In-Charge. When the  Geophysics Division was formed in 1951 it in turn assumed control of the Apia Observatory. The meteorological programme continued as part of the New Zealand Meteorological Service until Western Samoa took over this work in January 1964.

The Eschenhagen variometers were replaced by new instruments in 1956. An Askania declinometer was installed in 1966 and a proton magnetometer in 1968. During the same period several changes had been made in the seismographs. Benioff instruments were installed at Afiamalu in 1957 and the Wiechert at Apia (the masses of which now form part of the foundations of a bridge) were replaced by a Word-Anderson seismograph. In 1963 a World Wide Standard Seismograph Station replaced the Beinoffs at Afiamalu. A visual Spregnether replaced the Wood-Anderson at Apia in 1968 and was itself superseded in 1971 by a visual Helicorder.

Western Samoan Independence - Joint Operation

In 1963 when Western Samoa achieved independent government most of the facilities established by New Zealand were transferred to the Government of Western Samoa. Similarly all staff became Western Samoan public servants but the New Zealand Government continued its financial responsibility for the geophysical programmes by reimbursing the Government of Western Samoa for salaries and by providing and maintaining the buildings and equipment. The entire responsibility for the meteorological programme has now been taken over by Samoa.

In 1970 a tide station was established at Apia Harbour to replace the lagoonal station of Mulinu'u. A remote-recording Bristol tide gauge provides chart recordings at the Observatory. A standard portable tide gauge also was operating at the Tide House until 1974. Both the tide gauges were provided by the Government of the United States of America for the International Tsunami Warning System.

Expansion of Activities at the Observatory

Enlargement of the Observatory's function has taken place in recent years by its use as a center for certain technical and research projects concerned with national development. In 1971 the Hydrological Services Project was established to investigate water resources in the country. The project was supported by the Food and Agriculture Organisation of the United Nations which provided staff and funds for groundwater investigations, and equipment to establish a network of hydro-meteorological stations and to commence surface water investigations. A series of five experimental boreholes was completed in 1972 and a number of hydro-meteorological stations was installed in areas with potential for water supply  and hydro-power development.

In 1974 the Government of Western Samoa gave highest priority to an early development of hydro-power in the country. During that year an intensive programme of hydrological data collection and data analyses started, financially and technically supported by the Asian Development Bank and the United Nations Office of Technical Cooperation. By the end of 1976 the hydro-meteorological network consisted of 16 stream-gauging stations, 30 rainfall stations and 3 fully equipped climate stations.