Infographic: Building a quake warning system
Scientists are expanding a quake sensor network that would eventually give the public a heads up before shaking arrives. Several grants since 1997 beefed up Southern California’s system — from about 20 stations in 1994 to more than 400 today. More sensors and funding are needed to complete the West Coast early warning network: California needs about 720 more stations, many in the north. Oregon and Washington need to increase their number from 224 to 550.
San
Francisco
Napa
Oakland
Berkeley
Epicenter
Strong shaking begins
Initial shaking
Strong shaking
begins to hit
San Francisco
Early earthquake
warning system
sends out alert
Quake begins
13.1 seconds
5.1 seconds
Zero seconds
10 MILES
Eight-second warning for San Francisco
How seismic stations work
Data and
power
conduit
9.5 feet
max.
Vault
cover
Landscape
bricks
Sensors
Concrete
base
Concrete
base
Recorded data is
transmitted to a central
location using cellular
and radio technology
in real time.
A prototype early earthquake warning system in
August provided San Francisco eight seconds of
warning that shaking from the Napa earthquake
was coming.
A system of seismic
sensors and a data
logger that detects and
records ground shaking
is placed in an
underground vault lined
with concrete and
high-density plastic.
Radio
antenna
GPS
antenna
Solar
pannel
Ground
shaking
Battery
Sources: California Integrated Seismic Network, Caltech and U.S. Geological Survey, UC Berkeley Seismological Laboratory; OpenStreetMap & Contributors.
@LATimesGraphics
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