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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

#71

Post by Sanddancer »

rdl wrote: post #58
VMG wrote: post #49

Earlier quoted context omitted.

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?

No. This would almost assuredly be sent as a level 2 extreme alert. The only alert that can bypass the settings is an alert directly from the president.

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

#73

Post by wellboy »

rdl wrote: 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.

There should be an app for that --> Yo.

Seriously, it should be a functionality of Yo. As of now you can subscribe to channels already, I think there should also be default channels that all users are subscribed to, for events that happens a few times a year and less.

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

#74

Post by nkozyra »

rdl wrote: 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.

But how much time is left after processing and delivery latency? I wonder if it could go from warning to end user within those 10 seconds.

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

#75

Post by miguelrochefort »

ghshephard wrote: post #38

Back in 1999/2000 I had a friend in Castro Valley call me in the morning to ask me if I was feeling the earthquake - I said nope, and then 5 seconds later - it hit me in Sunnyvale. That's another way of earthquake advance warning - taking advantage of the latency between the epicenter and the surrounding area.

This is exactly what the system does...

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

#76

Post by rwg »

michaelt wrote: post #64
rwg wrote: post #54

Earlier quoted context omitted.

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…

How cheap is dirt cheap? $1000? $100? $10? $1? $0.1? Are there established algorithms to determine what seismic data is 'interesting' as opposed to streaming it all in real time (and keeping the radio on) constantly? Why 802.11n instead of cell phone networks - don't you need to be away from traffic vibrations, and hence roads and homes?

How cheap is dirt cheap? $1000? $100? $10? $1? $0.1?

I think a sub-$500 per-station cost would be wonderful, but this is all just a pipe dream...

Are there established algorithms to determine what seismic data is 'interesting' as opposed to streaming it all in real time (and keeping the radio on) constantly?

Almost all digitizers I've seen support the same STA/LTA (short term average ÷ long term average) triggering mechanism, where data is declared interesting if the energy over a short time window divided by the energy over a long time window exceeds some configurable threshold. If you only send triggered data, it's a great way to trigger repeatedly on local noise and miss all/parts of events you actually want to record.

Sending continuous data from stations to a central processing site is greatly preferred, especially since the data rate is so low. Three channels of 20-bit, 100 samples/s data from a low- to moderate-noise site that's losslessly compressed by the digitizer fits comfortably in 9600 bits/s.

Why 802.11n instead of cell phone networks - don't you need to be away from traffic vibrations, and hence roads and homes?

Siting seismograph stations is a tradeoff. Too far away from civilization and you have no way to get data back home except via (expensive, power hungry) VSAT or high power radios. Too close to civilization and you are subjected to civilization's noise (but you can use civilization's communications infrastructure to send your data home, sometimes for free).

The higher a site's noise level, the higher your event detection threshold gets. In other words, the noise consumes the signal from weak and/or distant earthquakes. You can make up for this somewhat by deploying a more dense network that pushes stations closer to where the earthquakes are happening...

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

#77

Post by blunte »

This post is a nice reminder of the privacy issues (and how users should really consider what information they choose to give away).

Yes scientifically this is interesting. But it also means that we are willingly allowing ourselves to be tracked to great detail. You know they have internal reports or queries to show who has sex and when. Not that this is a big deal - we're human, and humans have sex. But it also can show who is having sex with whom, in some cases.

How long until Jawbone starts receiving court requests for this? (probably already happens).

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

#78

Post by ghshephard »

miguelrochefort wrote: post #75
ghshephard wrote: post #38

Back in 1999/2000 I had a friend in Castro Valley call me in the morning to ask me if I was feeling the earthquake - I said nope, and then 5 seconds later - it hit me in Sunnyvale. That's another way of earthquake advance warning - taking advantage of the latency between the epicenter and the surrounding area.

This is exactly what the system does...

I realized that after reading the threads, and some related articles.

I don't really understand why anybody felt a need to "announce" that the early warning system, "Worked" - I would presume that it has always been the case (at least since tele-connected seismometers were invented) that there has been an early warning of every earthquake from sites that were remote to where the sensors were.

Presumably this is Earthquake Monitoring/Alert systems 101. (And, in Japan they've greatly advanced the signaling to the public)

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

#79

Post by twistedpair »

freditup wrote: post #8
waiwai933 wrote: post #4

Earlier quoted context omitted.

If the system were relatively reliable, 10 seconds is actually a lot of time. During the day, it's enough time for many people to take cover. During the night, it's enough time to at least get people up and semi-oriented. The other thing to note is that earthquakes are much shorter than most people think, usually about a minute long. 10 seconds is quite a bit of time compared to that.

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.

> But there's no way to reliably get information to all people within ten seconds.

This is HN, right? Come on folks. If I can send packs transcontinental and back in 100ms, then you can get a message out to the people of CA in under 10s. This is not a moon shot project. Our entire telecomm infrastructure operates in ms increments, not 10s increments.

Now, if only the SF startups could work on something useful like this, rather than yet another cat video app. You could even show ads for home repair companies and insurance adjusters during the warning/quake.

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

#80

Post by jofer »

rwg wrote: post #54
largote wrote: 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…

Just in case folks are wondering why funding for seismometer networks has fallen off a cliff, it's not what you might think. It's due to the end of the cold war.

From the 50's to the 80's there was a significant amount of defense funding (mostly DARPA) for seismic monitoring to detect, locate, and analyze nuclear detonations in addition to civilian research purposes. After the cold war ended, the majority of the military funding went away.

Also, on a side note, for those of you looking at the hardware description and thinking "all that exists", notice the sample rate and power requirements. (Don't forget data transmission and/or storage, either.) It's already possible to get dirt cheap sensors. (For some purposes (e.g. surface waves), off-the-shelf accelerometers are good enough, and even traditional oil industry geophones are fairly cheap.) (Obviously broadband stations are a completely different story...) The problem is sample rate and power draw.

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