Last month, shortly after the two, big, back-to-back quakes that rocked California, I wrote about an app that Los Angeles residents can install on their phones to warn them about earthquakes. It’s called ShakeAlert, and it’s one of the more practical ideas that any municipal government has come up with, in living memory. But there was one glaring problem that showed up quickly. Neither of those quakes triggered the app, so Angelinos received no warning about them.
The problem, as it turned out, was that the app didn’t look for quakes outside the borders of Los Angeles, and when tremors were felt inside the city it wasn’t triggered unless the quake registered magnitude five or higher. Since those two big quakes were centered to the northwest and the actual shaking inside the city didn’t reach level five, no alert was sounded. Well, after a few weeks of review, the city made some changes this week to improve matters. (CBS Los Angeles)
Although the notification system worked correctly, USGS had designed the app so that an alert would only be sent out if shaking registered at a threshold of magnitude 5.0 within L.A. County.
Since neither earthquake registered at a 5.0, residents did not receive an alert. Based on the criticism the city and USGS received, on July 24 the threshold for notifications was lowered to magnitude 4.5.
The ShakeAlert system is based on a network of in-ground sensors developed by USGS to detect seismic activity.
Perhaps getting an alert for magnitude 4.5 tremors is better than leaving it at 5.0. If that works better for the residents of the city, great. But I feel compelled to ask the same question I posed last month since it hasn’t been addressed here. Seriously large (magnitude 7 and above) quakes can travel a very long distance, just as we saw last month. But the way the Los Angeles system is set up, you’re not going to get a warning until the quake is already upon you, or at best a second or two before.
Couldn’t this system have a higher threshold for quakes centered further away? If the USGS registers a magnitude 7 quake fifty miles to the north and that triggered an immediate alert in Los Angeles, that might give them up to a minute to get outside, under a doorway, into a bathtub or whatever their disaster plan suggests. I’m neither a tech guy nor a geologist, so I’m just spitballing here, but doesn’t that seem like it would be more useful?
On a related topic, earlier today I wrote about the tsunami threat facing Oregon (as well as most of that region of the coast) and it got me to wondering. Does Oregon have a tsunami app?
They sure do! It’s provided by FEMA. I was unable to find a demo of the app, but if it performs as advertised it might be one of the most useful things you could ever put on your phone. (Assuming you live in the area under threat.) If that big subduction zone off the pacific northwest coast pounds out another killer quake and this app goes off immediately, residents could have up to ninety minutes to get to higher ground. That could be a life or death difference.
But the app doesn’t just warn you that a tsunami may be imminent. It tracks your location and provides maps to the closet routes to safety, shelters and emergency services. It’s rare that we get the chance here to write about the government actually doing something useful, so it’s a happy day when we can point out a story like this one.