ENG-1980 — Page 305

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THE ENVIRONMENT

At the end of the year, the observatory was awaiting delivery of two new acoustic radars (or sodars), which will be installed early in 1981 at Chek Lap Kok Meteorological Station and at the Lok On Pai Desalting Plant to investigate turbulence in connection with the feasibility study for the proposed new airport. These instruments emit sound upwards and record the echoes caused by temperature and wind irregularities in the atmosphere. Geomagnetic observations continued to be made, in a joint project with the University of Hong Kong, at a geomagnetic station on Tate's Cairn. The observatory also monitors radioactivity. Routine measurements of the beta and gamma radioactivity and the levels of sulphur dioxide and particulates are made at King's Park Meteorological Station in Kowloon.

In another development during the year, a new network of three short-period seismo- meters was connected to a central microcomputer at the Royal Observatory. The system is now capable of detecting tremors throughout Southeast Asia and computing the epicentres of earthquakes automatically. The system located blasting on Lamma Island and Tap Shek Kok with an accuracy of about 200 metres; it has also detected some weak earthquakes in the sea-bed south of Lamma Island. An earthquake that it located in the Taiwan Strait at 0238 GMT on May 8, 1980, was felt by residents in Hong Kong.

Long-period seismographs are operated in a cellar at the Royal Observatory and record tremors from all over the world. The largest earthquake recorded was of Magnitude 8 on the Richter scale and occurred in the New Hebrides on July 17, 1980.

An eclipse of the sun on February 16, 1980, aroused considerable interest and the Hong Kong Amateur Astronomical Society organised a scientific expedition to Kunming, in China, to make observations.

Research

One of the objectives of research at the Royal Observatory is to investigate aspects of the local climate and to present the results in a convenient manner. Altogether, about 230 technical publications have been written on a wide range of subjects.

Research is also directed at improving the observatory's own forecasts and improving its instruments. In 1980, there was an investigation of the relationship between windshear actually experienced by aircraft and the windshear measured by the five anemometers located round the Hong Kong International Airport. A comparison was made between measurements by radiosondes used in China with those used in Hong Kong.