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THE ENVIRONMENT
which provides a more uniform time scale than that based upon astronomical stand- ards. The UTC will never differ by more than 0.7 second from the astronomical time. To ensure this, step adjustments to UTC of one whole second will be made whenever necessary.
Twelve seismometers are operated by the Observatory. The department prepares bulletins of all earthquake tremors recorded and participates in the Pacific Tsunami Warning Service. Hong Kong lies just outside the circum-Pacific seismic belt and has not suffered serious earthquake damage since 1918. However, an average of two to three tremors may be felt each year by residents in certain locations such as on balconies of high buildings. Nine such tremors occurred in 1972 and the strongest was of intensity three to four in the modified Mercalli Scale on December 18, 1972.
Geomagnetic measurements, which 'ceased in 1941 and resumed in 1971, were regularly made at the geomagnetic station near Tate's Cairn, where magnetic variation was also recorded. This was made possible with a donation from the Nuffield Founda- tion for a joint project by the University of Hong Kong and the Royal Observatory.
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The Observatory answers requests for climatological and meteorological informa- tion from various government departments, firms and the general public, and issues certificates for litigation purposes and for insurance claims. The department also acts in an advisory capacity in the planning of many projects in the territory that may be affected by meteorological conditions. Technical papers are published on various aspects of the weather of Hong Kong and on a wide variety of geophysical subjects.
Plans were approved for the Royal Observatory to use computer facilities to process all incoming meteorological data received through communication networks so that the information can be more fully utilised, particularly for the preparation of tropical cyclone forecasts under operational conditions.
The Committee for Scientific Co-ordination is chaired by the Director of the Royal Observatory and was established in 1962 to advise the government on scien- tific and technological matters and policies and to co-ordinate scientific activities in Hong Kong. During the year, the committee supported many scientific exhibitions by allocating financial assistance from the UNESCO International Participation Programme Funds. The committee also made preparations to host a special sym- posium in 1973--under the auspices of the Pacific Science Association-on ‘Marine Sciences' and 'Problems of High Density Living'.
Research
Apart from basic research activities in connection with operational requirements of the department, numerous investigations were carried out on various aspects of meteorology and geophysics to meet the demand for services by aviation, shipping, industry and the general public. Many of the enquiries called for answers in a short time while a number involved detailed investigation using computer facilities. The latter included an analysis of sea-waves and swell in the South China Sea for a harbour project and a frequency study of winds over Hong Kong for the construction of a multi-storey hotel. In addition, studies were made of various problems concerning