DisastersMexico has an earthquake warning system, why not California?

Published 26 March 2012

Mexico has a functioning and apparently life-saving earthquake warning system in place; California’s system is stuck in a permanent test phase due primarily to lack of funding

Thanks to its earthquake warning system, property damage but no fatalities // Source: veracruzenlanoticia.com

In 1985 Mexico City suffered a magnitude 8 earthquake that killed an estimated 10,000 people, along with the attendant property damage.

Last Tuesday, on 20 March, while residents of Mexico City were at work, alarms began sounding, the air being pierced with sirens and recorded messages that an earthquake was imminent. The Bay Citizen reports that security officers directed people to prearranged safety zones, and, according to resident Alicia Montel Rodriguez, “About 10 seconds after everybody got to their zone, the earthquake started.”

The result of the 7.4 Richter quake was the expected damage, and some building collapses, but no apparent deaths.

A similar early-warning system was planned for the Bay Area and the West Coast, but has been stuck in a perpetual test phase for the last five years.

The problem is funding, coupled with different geological conditions than Mexico has to deal with. The source of Mexican earthquakes tends to be fault lines which are located offshore.

California’s land mass, however, is crisscrossed with fault lines, which may shift, resulting in additional pressure on adjacent faults and increasing the likelihood of a more substantial quake.

The developing California system depends on computer analysis from about 400 of the 1,000 in-place sensors. This data would show both the epicenter and the movement of the tremors from the epicenter.

Computers can make the movement calculations in seconds, but must still transmit the warnings faster than the tremors move, which is an estimated two miles per second. This could allow even ten seconds warning, which would allow time for a variety of actions to take place that could lessen death and injury.

Coupled with drills, announced and unannounced, public reaction has adapted to be as swift as time allows, without the panic that such a warning would induce.

The key, however, remains funding to increase the number of sensors, improve computer and communications, and improve operational efficiency.

In the current fiscal environment, though, that funding is not a high priority.