Casualties among children from earthquakes could be reduced after the installation of an earthquake alert system is completed this month, the Central Weather Bureau (CWB) said yesterday.
Kuo Kai-wen (郭鎧紋), director of the bureau’s seismology center, said the bureau completed the installation of an early earthquake warning system in 3,500 elementary schools nationwide earlier this month, adding that the system is not designed to forecast earthquakes.
“Each school is equipped with a computer system, to which a warning message can be sent within 10 seconds of an earthquake striking,” Kuo said.
“The message only says where the epicenter was, and the computer then estimates the level of intensity caused by the earthquake in that locality,” Kuo added.
“The system could help schools gain about 20 seconds to respond before the secondary earthquake waves [S-Wave] arrives, which cause the most damage,” Kuo said, adding that the system functions best when the epicenter is about 100km away.
Meanwhile, Kuo said that with the installation of many deep-well observatories, the center is now better equipped to identify the location of blind thrust fault lines.
The center has identified about 30 active faults, but there remain many blind thrust faults.
The number of earthquakes below magnitude 1 detected has greatly increased because of the observatories, Kuo said.
According to Kuo, less than 100 magnitude 1 earthquakes were detected per year before 2008.
After the bureau installed the observatories in 2008, the number of detected magnitude 1 earthquakes annually has gradually increased, reaching 4,000 last year.
“Though the magnitude 1 earthquakes do not do much damage, we can still use the number of the earthquakes in certain locations to identify where the blind thrust faults are. It would help build up useful data before a more dangerous earthquake occurs,” he said.
Kuo said that 30 deep-well observatories are currently in use, adding that 11 new ones are scheduled to be opened by the middle of next year.
The bureau plans to gradually expand the number of deep-well observatories to 70, he said.
To build such an observatory, an earthquake detection device must be placed 300m below surface.
It takes about NT$10 million (US$333,600) to build such facilities, including costs of drilling wells, installing broadband transmission networks and other equipment, the bureau said.