As a land that suffers frequent earthquakes, how to effectively alert people to the natural disaster has been the subject of much research in Taiwan.
Now, a National Taiwan University (NTU) academic has made a breakthrough that could help save lives.
NTU Department of Geosciences professor Wu Yih-min (吳逸民) yesterday unveiled an earthquake sensor that could help the Central Weather Bureau issue an earthquake alert 10 to 30 seconds before destructive shock waves hit a location.
Showing reporters a tiny sensor in an iron box, Wu said the technique was based on the difference in the speed at which horizontal and vertical waves travel.
“If an earthquake takes place in Hualien, it would take the P-waves [vertical] 15 seconds to travel [to Taipei] ... but it would take the S- waves [horizontal] 30 seconds to arrive here. So we would still have about 10 seconds to issue a warning,” Wu said.
P-waves are less destructive and travel faster than S-waves.
Wu’s device, which costs about NT$1,000, monitors earthquakes on land and offshore and calculates their intensity and scale.
Similar, but slower, devices had been adopted in the US, Japan, Italy and South Korea, Wu said.
Wu’s research has been published in journals such as the Geophysical Research Letters.
Central Weather Bureau Seismology Center Director Kuo Kai-wen (郭鎧紋) said the bureau worked with Wu and other scientists at NTU and the National Center for Research on Earthquake Engineering for many years, although he said he had yet to read Wu’s article.
Commenting on Wu’s system, Kuo said: “The point is to send out accurate messages in the quickest time possible.”
“We can quickly send out messages to schools or nuclear power plants, but they must also be able to interpret the information and take appropriate measures,” Kuo said.
Kuo said the bureau has been involved in an 18-year plan to gradually reduce the time needed to disseminate earthquake information since 1991.
By 1998, the bureau had succeeded in reducing the time it took to alert people to earthquakes from within 30 minutes to 30 seconds after an earthquake begins.
Starting next year, the bureau will aim to cut the time it takes to report an earthquake from 30 seconds to 20 seconds. To avoid ground interference, the bureau is planning to drill 40 wells at a depth of 200m around the country to install underground earthquake detectors. In the meantime, it is installing undersea cables along the East Coast to monitor undersea earthquakes as well.
The bureau has also installed earthquake detectors at 40 of the Taiwan Railway Administration’s power substations.
The detectors will automatically shut down the railway’s power system if they report an earthquake that exceeds 5 on the Richter Scale. Trains used in the high-speed rail system were equipped with a similar system when they were purchased.