Mid-Levels quake detector extends range thousands of kilometres
The Observatory yesterday unveiled the city's most advanced seismographic station, which can detect earthquakes thousands of kilometres away.
Senior scientific officer Dr Wong Wing-tak said there was a need to have a better monitoring system to provide early warning, even though the risk of earthquakes and tsunami hitting the city remains low.
'If there is an earthquake in the South China Sea, we will be able to determine the epicentre and magnitude early, so that if there is a threat of tsunami we may issue a warning as early as possible,' Wong said.
The Po Shan Seismographic Station is deep inside a 300-metre long tunnel on Po Shan Road in Mid-Levels. The state-of-the-art equipment in the facility was made in Sweden and the United States and cost HK$3 million.
The observatory spent an additional HK$1 million on further construction work to set up the tunnel.
Inside the station, a broadband seismometer and a strong motion accelerometer can detect earthquakes thousands of kilometres away. It is a significant improvement on the existing network of eight seismographic stations, which can only detect earthquakes accurately within 200 kilometres of Hong Kong.
The existing stations - at Cape D'Aguilar, Cheung Chau, Keung Shan, Lead Mine Pass, Luk Keng, Siu Lam, Tsim Bei Tsui and Yuen Ng Fan - would continue to operate to provide data, Wong said.
Being deep in a tunnel, the seismographic station is isolated from the city's noise and shockwaves, such as from motor vehicles and construction work. The key equipment at the station is wrapped in insulating material to guard against humidity.
Outside the tunnel, a global- positioning system collects precise data in real time, which is then transferred via fibre-optic cables into the tunnel for use with other data.
The Civil Engineering and Development Department originally dug the tunnel as part of landslide prevention works.
In 2006 it was suggested that the observatory should build advanced facilities to monitor earthquakes in the South China Sea.
