SEATTLE -- Imagine getting a text alert on your cellphone.
An earthquake is coming. You have 15 seconds - at most - before it hits.
How much could you really prepare for in 15 seconds?
A lot, says Douglas Given, United States Geological Survey's Early Warning Coordinator.
"Early warning, of even a few seconds, would give you a jump on protective action," Given says. "There are lots of situations where a few seconds or even tens of seconds of warning is enough to get out of harm's way."
How does it work?
USGS's Shake Alert Early Warning system is rolling out this year in Seattle, Los Angeles and San Francisco. Using a network of 850 sensors, the Shake Alert Early Warning system will detect an earthquake at one seismograph, then send warnings to other areas before that same earthquake can hit a few miles away.
The initial roll out will give warnings to some governmental and transportation agencies, but the ultimate hope is to have an sent to cellphones in the area. It's not an earthquake predictor, Given says, but a way to know a few seconds early that a potentially destructive earthquake is coming.
"The amount of time you get depends on your distance from the earthquake," Given says, noting that locations further away from the epicenter will have more warning time.
Given and other researchers started building Shake Alert in 2006. They hope to put 1,675 sensors down, and have a comprehensive warning system for the entire West Coast. This year's launch will serve agencies capable of utilizing an automatic system, such as one that could immediately shut off heavy machinery or slow trains.
"There are hundreds of things that can done with an automatic system," Given said.
'This can help reduce mass casualty events'
San Francisco's rapid transportation system, BART, has been using Shake Alert since 2012, Given says. When an earthquake is spotted, BART almost instantaneously slows down its trains through a computer system. With research showing trains have a tendency to derail during an earthquake, this automatic application may save hundreds.
"They saw the value of (Shake Alert) very early on," Given says. "This can help reduce mass casualty events. There are all sorts of applications for early warning."
But the idea of the Seattle resident getting a text alert - notifying them that an earthquake is coming - is about 3 to 5 years off, Given says.
A personal early warning system is blocked by the speed in which alerts can be sent. Working with the cell companies and agencies like FEMA, it would still take almost a minute to send out mass warnings. Too long for an earthquake warning, Given says.
"One of the specific limitations of our limited public roll-out is the ability to do mass notifications to the public fast enough," Given says. "It's not an unreasonable expectation, it's just not possible to do it yet."
How much warning will we ever get?
Given says USGS is working with FEMA and the cell industry to reduce delays. A pilot project for individuals is in the works at a few agencies in Los Angeles.
Given was not sure which companies and agencies in Seattle signed up for the early warning system, noting it would be "a number of technical and industrial users." He knew of at least one water company that planned to use the Shake Alert system in Seattle, shutting down certain pumps to prevent against damage.
Given was clear to remind people this isn't earthquake prediction, it's just "very rapid detection." Ten or 20 seconds seems about the best warning we can get, as a sort of earthquake prediction seems is almost impossible, Given says.
"You're not ever going to get 10 minutes," Given says.
The USGS will host a free public lecture on the Shake Alert system in California Thursday night, and it's available on live-stream.