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Earthquake early-warning system gave 10-second alert before Napa quake felt

latimes.com

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Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#51
post #28

Earlier quoted context omitted.

Which might mean getting to a safe place 20 seconds into the earthquake instead of 30 seconds into it. I wouldn't downplay this.

You can get under a table in 5 seconds. That's a change between life and death by having your fridge or large shelf fall on you.

If i lived in an area of tectonic activity I'm pretty sure i'd anchor my fridge to the wall

Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#52
post #28

Earlier quoted context omitted.

You can get under a table in 5 seconds. That's a change between life and death by having your fridge or large shelf fall on you.

If i lived in an area of tectonic activity I'm pretty sure i'd anchor my fridge to the wall

Unlikely. The Bay Area is an area of "tectonic activity" (as evidenced by Loma Prieta in 1989, and now the the 6.0 from yesterday) - but I"m willing to wager fewer than 1 in a thousand people anchor their fridge to the wall.

Hot water heaters and book cases - Yes. But not fridges. They rarely tip over in earthquakes.

Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#53

Earlier quoted context omitted.

If i lived in an area of tectonic activity I'm pretty sure i'd anchor my fridge to the wall

Unlikely. The Bay Area is an area of "tectonic activity" (as evidenced by Loma Prieta in 1989, and now the the 6.0 from yesterday) - but I"m willing to wager fewer than 1 in a thousand people anchor their fridge to the wall. Hot water heaters and book cases - Yes. But not fridges. They rarely tip over in earthquakes.

I'm not really afraid of what happens if my fridge tips over, either. I spend very little time in front of the fridge, and never when anything but fully alert. If the room started shaking, I could probably step a little to the left or to the right and be fine. I'm probably more concerned about all the glasses on high shelves, or the knives, etc., in terms of floor hazards after the quake.

The thing which terrifies me is that I'm in a 1971-construction building with a soft story, in a city with a defective police department. My car is parked in that soft story. Assuming the entire building doesn't collapse and kill me, there's nothing above my-standing-height except one projector, which even from projector-height, would be unlikely to kill me. But I'd probably have fallen to my death and been crushed by huge volumes of unreinforced masonry before that.

(Please, please, if there's going to be an earthquake while I'm in the Bay Area, let it happened while I'm in the office, or even better, in a datacenter. The new office is being fully retrofitted right now, so it should be pretty good.)

Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#54
post #33

Japan, Mexico City, and other seismically active places, have such systems in place and have had them for years. Amazing that California, the epicenter of tech, is just getting on board with this.

As someone who used to work for a university's geosciences department as a Unix sysadmin/programmer and who worked on two different seismic monitoring networks (one spread across the state for earthquake monitoring and one parked on top of a coal mine), allow me to explain why earthquake monitoring in the United States is largely stuck in the stone age: There's no f---ing money.

Back in the '80s, there were a lot of regional seismic networks around the country, especially east of the Mississippi. But as time marched on and budgets got slashed, regional seismic networks disappeared one by one. Today, only the largest regional networks survive — generally the ones that are mostly funded by the states they're in and/or have increased their share of USGS/ANSS funding by taking over monitoring for areas of the country that used to be covered by the now-defunct networks.

The regional seismic networks that are left spend pretty much all of their dollars on equipment and operations. Installing/upgrading/running permanent seismograph stations is expensive — a basic solar-powered one with a shallow fiberglass vault, a three component short period sensor, and a three channel digitizer will run you ~$12,000 just in equipment and materials. The sky's the limit if you go fancier than that (broadband sensors, strong motion sensors, atmospheric sensors, borehole sensors, six channel digitizer, elaborate vaults, VSAT, etc.). Then there's the recurring communications cost, the cost of regular site visits, the cost of regular battery replacements, replacing solar panels/equipment boxes that morons shoot at for laughs, etc.

What I'm getting at is that in the monetary battles of "keep seismograph stations working" vs. "hire programmer to write useful software", the stations will win every time. Even this LA Times article about Berkeley's early warning system notes, "A lack of funds, however, has slowed the system's progress."

If the epicenter of tech wants to do something wonderful for earthquake seismology, figure out how to make dirt cheap 1- or 3-channel seismic digitizers (low-pass filter + low noise amp + 20-bit ADC @ 100–200 accurately timestamped samples/s, ≤1 watt average power draw @ 12 VDC, speaks TCP/IP over 802.11g/n) and dirt cheap 1- or 3-component short period sensors (1 or 2 Hz corner frequency, decent sensitivity). Then figure out how to get thousands of these dirt cheap digitizers and sensors in backyards all over the country and contributing data in real-time to IRIS and/or the closest regional seismic network. If the cost of acquiring quality seismic data goes down, that frees up money to actually do something with the data.

When I was still at the university job, my job-related pipe dream was to blanket the state with these non-existent dirt cheap stations. Even one or two per county in my state would've increased our station count by a factor of >15, greatly improved the quality of our earthquake locations, and allowed us to determine focal mechanisms (the orientation of the fault and direction of the slip) even for small earthquakes.

Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#55
post #40

Earlier quoted context omitted.

I've got to say that my experience with Amber Alerts is strongly negative. For a while they were triggering various alerts (including EBS interruptions on radio and TV), with a frequency that lead me to strongly discount such warnings. Emergencies should be reserved for circumstances in which the recipient of a message can and should take immediate action. An alert is just that: an advisory. Run these was an item in…

And yet, at least once, the alert on the phone specifically (rather than a newscast or highway signage) appears to have saved at least one life[0]. Of course, we don't know what would have happened, and it did wake up the whole state, too. But I think the argument in favor is that the probability of success for these searches decreases quickly with time, so there is substantial value in getting word out quickly. [0]…

The argument isn't whether the alert alerts, but whether over-usage conditions people to ignore the alert.

If this kind of usage of the alerting system causes people to ignore alerts in the middle of the night, and then an earthquake happens, then the system is counter-effective. Based solely on the situation as laid out in the article, the people deciding on using the system in this case should be strongly reprimanded for squandering trust like that.

If using the system in such cases is actually desirable, a lower tier of alerts that doesn't make more noise than a regular text message should be introduced. It's not like someone sound asleep at 1am is going to go searching for a Suburban just because they were woken up. Indeed, the car was only found by someone going about their regular business in the morning.

Also, the system can't really be said to have saved one life in this case - it probably contributed to reuniting the child with its parent quicker, but there's no evidence suggested in the article that the kid would have died if not for the alerting system.

Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#56
post #2

A few seconds warning seems like it might be kind of useless for humans, especially at 3am, but it would be cool to have this feed into automatic systems to automatically put them in a "safer" state before an earthquake hits. It might even be that 10 false positives a day are worth it to catch one real event, if the "safing" operation is relatively non-disruptive.

>> It might even be that 10 false positives a day are worth it to catch one real event, if the "safing" operation is relatively non-disruptive.

This will cause so much panic that people will ignore them at some point. 10 false positives (even 1 a day) just make the system unreliable.

Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#57
post #56
post #2

A few seconds warning seems like it might be kind of useless for humans, especially at 3am, but it would be cool to have this feed into automatic systems to automatically put them in a "safer" state before an earthquake hits. It might even be that 10 false positives a day are worth it to catch one real event, if the "safing" operation is relatively non-disruptive.

>> It might even be that 10 false positives a day are worth it to catch one real event, if the "safing" operation is relatively non-disruptive. This will cause so much panic that people will ignore them at some point. 10 false positives (even 1 a day) just make the system unreliable.

OP seems to be talking about "automated systems". A harddisk might stop reading/writing for moment and park the heads to avoid a head-crash and things like that.

Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#58
post #49

Earlier quoted context omitted.

How about the delay? The message is not delivered instantly. Plus, such a system would be required to be already scaled up, and stay in that state always, to support sending messages to millions of "subscribers", which would only add additional delay.

If you use broadcast messages, the number of subscribers shouldn't matter. There already exists a system like this in the US: http://en.wikipedia.org/wiki/Commercial_Mobile_Alert_System > CMAS will allow federal agencies to accept and aggregate alerts from the President of the United States, the National Weather Service (NWS) and emergency operations centers, and send the alerts to participating wireless providers wh…

Will CMAS/cell broadcast bypass iOS Amber Alert and Emergency Alert "Government Alert" settings?

Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#59
post #11
post #8

Earlier quoted context omitted.

But there's no way to reliably get information to all people within ten seconds. Even if a text message alert was sent out as soon as the system was triggered, that time, plus the time for even the most phone-ready people to pull out their phone and do the necessary steps to read a message leads to basically no warning at all.

In Japan, all phones (even the iPhone) are setup to emit a loud alarm sound when an earthquake warning is sent, whether your phone is on manner mode or not. The alarm sound is very distinctive and the same for all phones as well as all TV channels.

It's actually not a japanese-specific setup. I got a japanese earthquake alert on my french Nexus 4. (and it was, fortunately, a false alarm; rare event, but that happens)

Re: Earthquake early-warning system gave 10-second alert before Napa quake felt

#60

Earlier quoted context omitted.

Excellent point. It could, for example, switch off gas lines at various checkpoints. I wonder how that might that affect appliances? For example, if a hot water heater is heating and the flame goes out, but then the gas comes back on is the heater smart enough to re-ignite the gas (or shut it off)?

Most things with a pilot light make use of a thermocouple to keep the gas from leaking out when no flame is present.

A thermocouple which won't shut off the gas immediately. However (targeting this mostly at GP), the amount of gas which will leak should be absolutely minimal and will soon disperse into nonignitability.
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