ENG-1965 — Page 287

232

GEOGRAPHY AND CLIMATE

serious earthquakes are almost unknown. However in most years a few tremors are felt. During 1965 only one such tremor was felt by local residents, at 2.21 a.m. on 18th May. The epicentre of this earthquake was about 370 miles east of Hong Kong near the southern tip of Taiwan. The general level of atmospheric radioactivity in the Colony is monitored at King's Park. During 1965 new equipment enabled 'Gamma' as well as 'Beta' particles to be counted.

RESEARCH AND APPLIED METEOROLOGY

In connexion with the design of new reservoirs, various studies were undertaken during the year into the size, duration and in- tensity of the worst rainstorm theoretically possible in Hong Kong and also the probable frequency of lesser storms. Special equipment was designed and built by the observatory to test the reception of the automatic picture transmissions from the two meteorological satellites, Tiros 8 and Nimbus 1, as they passed over Hong Kong. In spite of considerable local radio interference some valuable pictures were obtained. International commitments involved re- search into the climatology of neighbouring sea areas and also the climate of East Asia, while other subjects investigated included tsunamis and the effects of atmospheric tides.

--

THE YEAR'S WEATHER

After the drought of 1963 and the exceptional number of typhoons of 1964, Hong Kong welcomed the return of comparatively normal weather in 1965. January and February were generally mild and sunny with very little rain. March was an exceptionally dry month. There was a pronounced cold surge on 7th March when the temperature dropped below 10°C for the first time in the year. There was less fog than usual although there were a few hours during 22nd-23rd March. The total rainfall during the first quarter amounted to only 1.53 inches compared with the normal amount of 5.94 inches.

April was unsettled with almost double the normal rainfall. There were strong monsoon winds on 11th April, and between 24th and 28th April fog and thunderstorms occurred almost simul- taneously. May was not as hot or humid as normal and the mean dew point was the lowest recorded in any May since 1887. There