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Shake Alert


((PKG)) SHAKE ALERT SYSTEM
((VOA Persian))
((Banner: Shake Alert))
((Reporter: Crystal Dilworth))
((Camera: Austin Harris, Kelly Butler))
((Adapted by: Martin Secrest))
((Map: Pasadena, California))
((Main characters: 1 female; 2 males))
((NATS))
((Pop-Up Banner: California’s ‘ShakeAlert’ earthquake
warning system uses in-ground and surface sensors))
((NATS))
((Locater: San Andreas Fault near Los Angeles, California))
((Elizabeth Cochran, Seismologist, US Geological
Service))
So, both along the fault, we like those sensors really close
the fault because that gives us really those first motions that
are coming out of the earthquake. It tells us the earthquake
has started. So, once that earthquake started, seismic waves
start travelling away from where that earthquake starts. ‘P
waves’ or primary waves are the first waves that arrive.
They’re faster and you feel sort of a jolt coming up beneath
you. The ‘S waves’ would travel along behind those and start
shaking you back and forth.
((NATS))
((Locater: In-ground wave sensor site, Pasadena,
California))
((Robert Michael De Groot, ShakeAlert Coordinator, US
Geological Service))
So, we’re in Pasadena and we’re at one of the seismic
stations. At the bottom of this vault, this is what it is. So, and
it moves relative to the earth and basically whatever happens
in here, gets turned into an electrical signal and boom. It
takes some very, very precise observation about what’s
happening.
((NATS))
((Dave Sotero, Communications Manager, Los Angeles
Metro Rail))
Well, we were one of the early adopters of the ShakeAlert
system. We implemented it in January of 2017 and it gives
us precious seconds to anticipate an earthquake that may be
coming to (the) Los Angeles area and that will enable us to
put an alert out to our operators. Part of the protocol is to
slow down the train as it is moving in advance of an
earthquake. So, the slower you’re moving, the more safely
you can operate the vehicle and stopping the vehicle is the
best course of action for a large scale event.
((NATS))
((Robert Michael De Groot, ShakeAlert Coordinator, US
Geological Service))
For very large earthquakes, the ShakeAlert early warning
system is going to use seismometers,
((Pop-Up Banner: GPS stations))
but with the really big earthquakes, we’re going to need
information from these stations because what’s going to
happen is that if there’s a really big earthquake, these
stations are going to move very quickly in a very short
amount of time. And that information is critical to understand
the biggest of earthquakes. We’re talking (about)
earthquakes that are magnitude 8 and above.
((NATS))
((Pop-Up Banner: Northeastern Japan. March 11, 2011.
Magnitude 9.0 earthquake and tsunami))
((Robert Michael De Groot, ShakeAlert Coordinator, US
Geological Service))
Big earthquakes in places like Iran and Indonesia and they
could stand to have their own earthquake early warning
systems and this has actually become a really interesting
international community. We’re all learning from each other.
One thing we want to do and the big currency of ShakeAlert
is time. Time is really important to us. Currently, the time that
it takes to get messages out is taking way too long and we
want to reduce what we call ‘latencies’ as much as possible.
So, we’re working with a whole array of partners, the
telecommunications industry. We’re working with mass
notification providers, to get those messages out as quickly
as possible.
((NATS))

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