The Next L.A. / Reinventing Our Future : PREPAREDNESS : Wired and Ready

Earthquake experts and seismologists say that with $100 million they could wire Southern California into a comprehensive early warning and damage reporting system which could give precious seconds of warning of a major quake. The sensors could help emergency workers determine where damage was worst and help scientists better understand the forces that produce severe temblors.

THE EARLY ALERT SYSTEM

A network of seismographs could be installed along major known faults in Southern California and tied into a wireless emergency network. The network would automatically be triggered by the first rumbles of a major earthquake seconds before the ground shocks could reach Los Angeles. Seismologists and geologists say such a system could give between 20 seconds and 30 seconds of warning in the event of a San Andreas Fault earthquake--long enough to automatically:

* Shut down critical utility lines

* Alert reservoir workers

* Sound school alarms

* Send high-rise elevators to open at the nearest floor

* Trigger stop lights

* Warn trains

* Wave off approaching aircraft.

Reality check: Such a system already exists in Japan, where it has been in use for more than a decade to shut down that country’s high-speed bullet trains safely at the first sign of a major quake. Seismologists and geophysicists say it would take a decade to create an effective early warning system in California.

HELP FROM SPACE

Global positioning system links monitoring stations to satellites, allowing scientists to measure the movements of the Earth’s crust over long distances with unprecedented precision. The GPS system gives them the opportunity to analyze the stresses and strains building up along fault lines in enough detail to better understand where major earthquakes might be imminent.

Reality check: There are already 10 GPS stations in Southern California continuously monitoring crustal motion. Geologists say they need a minimum of 50 permanent ground receivers.

INSTANT DAMAGE REPORTS

Sensitive earthquake monitoring devices would measure the strength of the actual local ground motion from an earthquake. Tied together by radio telemetry, they would help emergency workers instantly pinpoint the areas of most severe damage while providing scientists the precise data they need to better diagnose the long-term vulnerability of specific neighborhoods to earthquake tremors. Engineers could use the data to strengthen local building codes and zoning ordinances. Sensitive earthquake monitoring devices would be installed on every major:

* Highway overpass

* Hospital

* Dam

* Pipeline

* Factory

* High-rise building

Reality check: Los Angeles already has 175 strong motion sensors, installed since 1972 by the Division of Mining and Geology. There are about 600 in the state. But many of the instruments are antiquated and geologists would need thousands more.

EARLY ALERT SYSTEM SEQUENCE

1. As a quake begins, low intensity waves travel out from the epicenter at about 4 miles a second.

2. The earthquake’s first wave triggers a seismic alarm system placed along the fault.

3. The fault seam continues to “unzip” as the quake ruptures the fault zone at about 2 miles a second and generates powerful but slower shock waves.

4. Alarm instantly transmits warning to computer at a central emergency center.

5. Emergency computer system automatically sounds area alarms and shuts down critical utility systems.

SOURCE: Southern California Earthquake Center, Caltech, U.S. Geological Survey