Earthquakes, unlike volcanic eruptions or floods, are very difficult to predict. It happens suddenly and leaves a huge huge toll behind. However, the technology to protect people from the damage caused by earthquakes is getting better.

California has installed an earthquake warning system that will send out alerts for seismic events. The state has launched the system on the 30th anniversary of the Loma Prieta. In this particular calamity, the tremors from the Santa Cruz mountains took around 35 seconds to reach the northern edge of San Fransisco. It is expected to warn people in advance so they may rush to an open area.

The system is called ShakeAlert and will send out messages using the MyShakeapp, which is available on both iOS and Android. It will work in a similar way to AMBER alerts that are issued for missing persons in the US.

California was hit by a 4.5 on Modified Mercalli Intensity scale earthquake, which hit central California at 4.7.

The alerts will take around one to two seconds to spread out to smartphones. The MyShakeApp will ring an alarm on phones when indoor shaking is expected. These alerts will be set at 4 on the Mercalli scale, which can lead to the clanking of dishes on the upper floors of a building.

"Nothing can replace families having a plan for earthquakes and other emergencies. And we know the Big One might be right around the corner. I encourage every Californian to download this app and ensure your family is earthquake ready," California Governor Gavin Newsom said in a statement.

The office of Emergency Services of California has spent around $8.5 million on the design of the system and promotion of the app, which is targeted at four million Californians. Hundreds of sensors will be installed throughout the state to ensure accurate and timely warnings of earthquakes.

In 1989, when the most destructive earthquake hit California, there was no way to prepare the residents for the natural calamity. However, with the unveiling of the app on Thursday, millions of people will get precious seconds to prepare themselves.

An earthquake of similar intensity could give perhaps 20 seconds of warning to the Marina District in San Francisco that was slammed by major fires, deaths and apartment collapses. Besides, the former site of Candlestick Park would get about 15 seconds of warning. Being closer to the epicenter, San Jose may have only a few seconds. However, for Santa Cruz residents, a warning sign was ruled out.

US Geological Survey Wales Earthquake
The US Geological Survey's map showing where people have reported feeling the quake and its epicenter. US Geological Survey