A Chengdu-based research institute set off an alarm within seconds of the 7.0 magnitude earthquake hitting Lushan county and surrounding areas Saturday morning, prompting a discussion on the need to establish a nationwide earthquake alarm mechanism.

The system, developed by the Institute of Care-life, a private research agency, sent alarms through local television networks, computer software, smartphone apps, the Internet and school broadcasting terminals to areas including Wenchuan county, Ya'an and Chengdu ahead of the earthquake's destructive secondary wave.

"A primary wave, which is not destructive, can be sensed and analyzed immediately while the destructive secondary wave reaches the ground later. Electromagnetic waves travel faster and therefore give us the time to send out alarms through radio, TV and the Internet before the secondary wave," Wang Tun, director of Care-life, told the Global Times.

Research by the Northwestern Seismological Journal shows that casualty numbers can be reduced by 14 percent with a three-second warning and by 63 percent if people have 20 seconds to take protective measures.

According to data automatically posted on the institute's Weibo account, Chengdu received alarms 28 seconds ahead of the secondary wave, while Ya'an got five seconds' warning.

The system was officially put into use in May 2012 after being tested over 1,200 times since 2008. It covers 400,000 square kilometers of land in eight provinces in Southwest and Northwest China, and is currently the biggest earthquake alarm system in the world.

"Many schools evacuated the students this time after the alarm, but we are the only mature system in China and the population we cover now is way too small," said Wang.

In addition to public broadcasts, the system is available on personal computers and smartphones for free. Download numbers skyrocketed in the past two days and a customer service representative told the Global Times that they have had to upgrade their servers to meet demand.

"An effective system has to be accurate and fast in delivering the message, which is difficult. However, its warning effect is quite limited in the epicenter area and works best in areas 100 to 200 kilometers away, where the destruction is smaller," said Zhao Kechang, an earthquake expert with Peking University.

Very few countries, including Japan and Mexico, currently have national earthquake alarm systems, and their effectiveness remains a source of controversy. But a staffer with the China Earthquake Administration told the Global Times that a 2-billion-yuan ($323.5 million) national alarm project has been approved and is now undergoing testing in Fujian Province.

"It's an urgent need. Our system gets good government support, but many local authorities are still reluctant to install it and we need more public education on the importance of earthquake alarms," said Wang.