Provide information on worldwide earthquakes of magnitude 5.0 or above and locally felt tremor as analyzed by the Hong Kong Observatory.
Earthquake information is preliminary analysed, generated and posted by computer systems without human intervention. However, the Observatory will disseminate locally felt earthquakes manually. The Observatory may update or delete any event when latest earthquake information is available.
For every earthquake not felt in Hong Kong, normally only one message would be posted which would include origin date and time of the earthquake (Hong Kong Time), magnitude, epicentre location in latitude and longitude, distance between epicenter and reference city, distance between epicenter and Hong Kong and reference region for the epicentre. For earth tremors felt in Hong Kong, local earthquake intensity in Hong Kong on the Modified Mercalli Intensity Scale will also be included.
The information in the HKO Earthquake Information webpage will be updated automatically once every minute. Users can choose to display part of the earthquake events according to selected origin time, magnitude, distance of the epicentre from Hong Kong. The longest period for events to be displayed is 30 days. According to past records, there were on average around 2,000 and 200 earthquakes of magnitude 5.0 or above and 6.0 or above respectively every year globally.
Past statistics indicated that the Observatory's computer system could detect earthquakes of magnitude 6.0 or above worldwide with detection efficiency reaching 98% while the the detection efficiency for magnitude 5.0 or above was about 90%.
The reference region for the epicentre is an approximate indication of the geographical location only. It is generated automatically based on Flinn-Engdahl regionalization scheme (1995 revision), which defines boundaries at one-degree intervals of latitude and longitude, and may not be consistent with the political region of the epicentre.