[HN Gopher] Seconds before a 6.2 earthquake rattled California, ...
___________________________________________________________________
Seconds before a 6.2 earthquake rattled California, phones got a
warning
Author : sizzle
Score : 218 points
Date : 2021-12-22 17:19 UTC (1 days ago)
(HTM) web link (www.theguardian.com)
(TXT) w3m dump (www.theguardian.com)
| jorgeudajer wrote:
| sva_ wrote:
| I'm currently on my first trip to the US, and was in Napa Valley
| at the time of that earthquake. I (sadly) didn't feel anything.
|
| It probably sounds weird, but I wish to experience a (light)
| earthquake sometime. The idea of the ground itself shaking seems
| absolutely alien to me.
| boringg wrote:
| Sub 4.2 earthquakes feel like a truck rumbling by your house
| (if you have an old house/apartment). I used to live on a busy
| street in SF and whenever there was an earthquake it was always
| ... was that a large truck or an earthquake. Only when it keep
| rattling did it really differentiate.
| minitoar wrote:
| It's more like everything is shaking. The fact that the source
| is the ground is not obvious in the moment.
| yesco wrote:
| I experienced my first and only earthquake (5.8 magnitude)
| while visiting the holocaust museum in Washington DC. It was
| very out of the ordinary for the region and so as strange as it
| sounds, myself, my family and some other people present all
| thought the shaking was a part of the exhibit and simply
| carried on.... only for a security guard to come running in
| several minutes later to kick us out of the building.
|
| I think earthquakes can by easy to miss sometimes for those
| unused to them because they feel so mundane. Like everyone's
| experienced a certain degree of shaking before, heck the
| turbulence in a plane isn't much different. This obviously
| changes at higher magnitudes but really changed my perspective.
| quartesixte wrote:
| There is nothing quite like it. The whole earth _moves_. It's
| like being on a boat but it's solid ground.
| joelbondurant0 wrote:
| mensetmanusman wrote:
| They should add an extra alert for people near the coast based on
| your gps altitude:
|
| "If this were a magnitude 8.5, you would have had 15 minutes
| before the tsunami reached your altitude."
| not2b wrote:
| There are already good tsunami warning systems in place in many
| vulnerable areas.
| klenwell wrote:
| I received my first and, as yet, only earthquake warning on my
| smart phone this past September for a 4.3 earthquake here in
| Southern California.
|
| It was an interesting fleeting experience. I was sitting on the
| couch, phone in hand, when it emitted an unusual fairly obnoxious
| noise. I glanced at the screen, saw the words earthquake and 4
| something, and understood what was being conveyed sort of
| inchoately without making it explicit sense of it. My wife was
| sitting next to me reading so I turned to her and tried to show
| it to her but she remained absorbed in her reading.
|
| Then the room jolted, rocked a little, and settled. The nice
| thing about the alert is I remained relaxed the whole time.
| Because the alert indicated the magnitude, I wasn't too worried
| about damage or personal injury.
|
| Now if it had warned of a larger earthquake, like a 5 or 6, I
| imagine I would have been more panicked. Still, the warning would
| have been even more valuable in that case.
|
| It was one of the more acute "Now this feels like living in the
| future" moments I've had recently.
| codegeek wrote:
| In case this helps, I recommend registering with nixle [0] for
| any emergency notifications to your phone. It provides more
| accurate and real time details from local agencies in your
| area.
|
| https://www.nixle.com/
| dfxm12 wrote:
| I've got no idea at what magnitude I should start worrying. I
| would assume, and hope, that if my phone (which is otherwise on
| silent) is blaring, it _must_ be a big deal. Maybe for some
| people a 4.3 is a big deal, but not for all...
| kevinmchugh wrote:
| Distance from the epicenter matters as well. I was 6 miles
| from a 4.9 last month, my first real earthquake. It was
| unsettling and concerning (including for the people I was on
| zoom with) but that was it. Nothing fell off the walls, iirc
| no fatalities or buildings demolished.
|
| The scale is logarithmic. My rule of thumb is that 5 is where
| things start to get much more dangerous.
| Enginerrrd wrote:
| Where I'm from, (Just a few miles from where this one was)
| we don't really start to worry until 7+.
| klenwell wrote:
| We had had an earthquake in low 5's here a couple years
| earlier. That was nerve-wracking but didn't do any damage. So
| I think I was gauging my reaction (mostly instinctively) off
| that.
|
| Actually, I just looked up the previous earthquake:
|
| https://earthquake.usgs.gov/earthquakes/eventpage/ci38457511.
| ..
|
| That one was a 7.1! Significantly larger than I remembered
| but more distant. I must have been thinking of an earlier
| earthquake.
| 323 wrote:
| Below 5 you only need to worry about objects in your
| immediate vicinity.
|
| Old/poorly built buildings start collapsing at about 6.
|
| Above 8, almost any building can collapse.
| lostlogin wrote:
| Christchurch, New Zealand was smashed by a 6.2. Pretty much
| as you say, older and poorly designed building didn't fare
| well, and the earlier 7.2 earthquake wouldn't have helped.
| It was a very shallow earthquake too.
|
| https://en.m.wikipedia.org/wiki/2011_Christchurch_earthquak
| e
| quartesixte wrote:
| Earthquake codes in California mitigate a lot of the
| intensity of a shake and its damage.
|
| Anecdotally, I heard to level Downtown Los Angeles
| completely it will have to be hit with some absurd
| Earthquake like a 9.0
| clairity wrote:
| a number of years ago, i worked in one of the downtown LA
| office towers when a 5.x earthquake hit. it was a jolt
| and rumble, and looking out the window, we saw the other
| towers nearby swaying back and forth. then we realized
| _we_ were also swaying back and forth. it was unnerving
| to say the least. the little engineer in me eventually
| kicked in to point out that that engineered-in
| flexibility was what kept us from breaking apart and
| crashing into the ground.
| njarboe wrote:
| The strike slip fault system in most of California can
| produce earthquakes up to about 8.0. Subduction zone
| earthquakes that occur in many places, like Northern
| California up to Alaska, Chile, Japan, etc, can produce
| 9+ earthquakes. 10 and above only occur during large
| impact events. So California can have buildings
| "earthquake proofed" for much lower cost than say Seattle
| and they come at higher frequency. That may be one of the
| reasons that California's infrastructure is pretty well
| prepared for coming earthquakes while Seattle will have
| major damage when the next 9.0 hits in 0-400 years.
| jandrewrogers wrote:
| The most dangerous fault line in Seattle, both in terms
| of earthquake and tsunami risk, is the eponymous system
| of shallow thrust faults[0] that run through the middle
| of the city and historically have produced ~7.0
| earthquakes.
|
| Seattle buildings built in the last 3 decades are
| explicitly designed to survive extreme earthquakes. Most
| of the risk is in the 1970s and earlier infrastructure,
| quite a lot of which has been torn down to make room for
| the massive growth of Seattle.
|
| [0] https://en.wikipedia.org/wiki/Seattle_Fault
| cutemonster wrote:
| > designed to survive extreme earthquakes
|
| What magnitude is that? (The highest they're designed to
| survive)
| hsod wrote:
| dredmorbius wrote:
| This depends greatly on building codes, structure contents,
| and local geology.
|
| In California and Japan, decades of stringent building
| codes mean that _most_ structures are likely to be safe
| agaist even large quakes, in the sense that occupants
| should survive, even if the structure itself is not
| repairable.
|
| Along the central and eastern US, and in large parts of
| rural China, Iran, Iraq, and Turkey, amongst other areas,
| building codes, geology, and general preparadness and
| awareness (or lack) can make even comparatively small
| quakes deadly.
|
| From the Rockies east, the US is underlayed by largely-
| intact limestone and a thick crust which can propagate
| seere ground movement hundreds of kilometers, up to 1,000
| km or more. By comparison, along th USwest coast, being 100
| --200 km from an epicentre usually renders even a large
| quake largely harmless (though it may still be felt).
| Additionally, construction standards in the central/eastern
| US and other regions mentioned above tend to result in far
| more severe structural damage. Rescue, aid, and shelter
| capabilities may also be limited.
|
| (In California, the principle geological hazard is fill or
| other soils prone to liquefaction, which can greatly
| amplify movement locally. Landslides may also be a concern.
| In mountains, rockslides.)
|
| The guidelines 323 gives are useful for California and
| Japan. Elsewhere, comparable damage might occur a magnitude
| below those given.
| ecpottinger wrote:
| Here in Ontario we had a small quake caused by a rock
| slide in Lake Ontario, almost no damage was seen. But my
| friend in Bowmanville said her grand mother lost tens of
| thousands of dollars in custom plates that she has
| displayed on ledges all around her house.
|
| Why? Because we never get earthquakes here, so there were
| no lifted edges or holders! Then suddenly we get a small
| quake, and they all came crashing down.
| dharmab wrote:
| If you live in an earthquake zone you quickly learn what a 2,
| 4, 6 feel like. It is a gossip topic in your community like
| the weather.
| cgriswald wrote:
| This isn't my experience at all and I've lived in the Bay
| Area nearly half my life. I have a vague idea of what a mag
| 4 earthquake feels like, and that's about it.
| antod wrote:
| Yeah that makes sense, people talk about what magnitude x
| "feels" like, but they're really describing an
| earthquakes intensity rather than magnitude. You don't
| directly "feel" the magnitude.
|
| Any given magnitude quake is going to feel very different
| for people in different situations - eg how far away, how
| deep, soil conditions, how tall the building they are in
| etc...
|
| Magnitude is related to how much energy is released -
| useful for seismologists and records, while intensity is
| related to ground acceleration and subjective effects
| which is useful for structural engineers and the public
| caught in one.
|
| eg that 6.2 magnitude Christchurch quake mentioned
| elsewhere still managed to produce some of the highest
| ever recorded vertical ground accelerations despite
| releasing a tiny fraction of what a really big quake can
| do.
| [deleted]
| Ancapistani wrote:
| If you live in an area with frequent earthquakes, yes.
|
| I live near the New Madrid. There aren't frequent
| earthquakes here at all, but historically when we do have
| one... it's a big one.
| zinekeller wrote:
| I think that although (estimated) magnitude is helpful,
| Japan's system also calculates the (estimated) intensity
| from the earthquake for your local area. Not always correct
| (but this tends to be rare), but usually within +/-1 of the
| Shindo scale (which is their local intensity scaling).
| Seems that ShakeAlert doesn't compute (yet, hopefully) the
| estimated intensity in your area.
| BurningFrog wrote:
| You start worrying at 5.0.
| rectang wrote:
| It depends how close you are to the epicenter, of course.
| Your figure seems about right to me: I think a 5.0 near an
| epicenter would be pretty violent. But I've never been near
| an epicenter -- only on the outskirts.
| ryantgtg wrote:
| Every time I feel an earthquake in LA, my first question
| is, "was that a small one near me or a big one far away?"
| antod wrote:
| You get a feel for that with the shaking frequency and/or
| gap between different sets of waves (P & S waves). No
| discernable gap and higher jerkier frequency usually
| means closer, a longer rolling feeling with separated
| phases that might last longer usually means further away.
|
| Just like sound or ocean waves the higher frequencies
| attenuate out quicker over distance.
| djrogers wrote:
| It also depends on what type of ground you're on. I've
| been in 5+ earthquakes in a house built on solid rock
| (Los Angeles area hills), and a 4.5 down in the valley.
| Being on loose ground makes it feel _much_ worse.
| leeoniya wrote:
| > I've got no idea at what magnitude I should start worrying
|
| ask your building inspector
| 14 wrote:
| This made me think one should almost practice like a fire alarm
| drill we do in grade schools. Set a random timer and when you
| get the alert react. Have it go off randomly some days so you
| can practice getting under a desk or in a doorway as fast as
| possible.
| FredFS456 wrote:
| Having attended grade school in BC, Canada, we used to do
| exactly that. Someone would come on the PA system to rattle
| some rocks in a jar and all students would duck under the
| desks until the 'earthquake' subsided, then count to 60 and
| quietly file out to the field.
| aleksiy123 wrote:
| Was it actually rocks in a jar? I always thought it was
| some kind of recording.
|
| Completely forget about this. Thanks for the random
| nostalgia hit.
| lostlogin wrote:
| This is done at school in New Zealand.
| magnusmundus wrote:
| In the years after the disaster of 1999 [1], we used to do
| exactly that in Turkey in the 2000s, couple times a year. I'm
| not sure when/why they stopped.
|
| On a not-too-closely-related note, the last time I heard of
| one was in 2013, when a group of riot police forcibly
| dispersed a civilian drill. This was a few months after the
| Gezi Park protests.
|
| 1: https://en.wikipedia.org/wiki/1999_%C4%B0zmit_earthquake
| bschwindHN wrote:
| I was once in my old Tokyo apartment on the 12th floor. I use
| an early earthquake warning app. It buzzed, telling me a 9.0
| occurred in Tokyo bay and I have approximately 3 seconds before
| the very extreme shaking starts. I just sat down and thought
| "welp I'm dead".
|
| It turned out to be a false alarm, triggered by something like
| a monitoring station being struck by lightning. I still have
| the screenshot of what the app looked like when it told me.
|
| Edit: found the screenshot:
|
| https://ibb.co/Lk4w5B4
| mensetmanusman wrote:
| Yikes, that reminds me of the false 'we are all going to be
| bombed soon, this is not a test' warning the people in Hawaii
| got... there should be penalties for false alarms like this.
| Enginerrrd wrote:
| I still find the official story behind the Hawaii thing to
| be kind of suspect.
| BitwiseFool wrote:
| I have extended family members who are employees of
| Hawaii's State Government. The stories they tell... Let
| me just say that the sheer incompetence and horrible
| systems design people claim are responsible for that day
| are entirely reasonable.
|
| The heart of the problem is that government jobs are
| extremely lucrative for the people of Hawaii because they
| pay well and because it is extraordinarily difficult to
| get fired from one. While direct nepotism isn't common,
| everyone is basically part of this giant extended family.
| Knowing the right person can land you one of these jobs-
| for-life even if you're _barely_ qualified for it. There
| is also a culture of not rocking the boat. Trying to get
| freeloaders fired subjects you to ostracism. So what ends
| up happening is a few people end up doing the majority of
| the work. While this isn 't unique to Hawaii, those
| people who are actually productive end up following their
| own version of 'the process' and the result is that
| people are rarely sure if what they are told to do is
| _really_ what they should be doing.
|
| I would like to submit this as supporting evidence: "A
| password for the Hawaii emergency agency was hiding in a
| public photo, written on a post-it note"
|
| https://www.businessinsider.in/tech/a-password-for-the-
| hawai...
| gibolt wrote:
| Incompetent Contractors made a terrible UI and a trainee
| didn't understand it. Pretty clear cut failure
| olivermarks wrote:
| Then congress person Gabbard was very clear there needed
| to be repercussions following the Hawaii nuclear strike
| alert fail.
| ecpottinger wrote:
| I seen too many times when something is made by someone
| who understands what the system does but never thinks
| what a rank beginner who is suddenly facing the same
| display going to think.
|
| It is hard to remember what it is like for someone new to
| a system.
| gibolt wrote:
| It isn't hard, it just requires active thought.
|
| Even better, get an uninitiated person and watch them try
| it.
| dredmorbius wrote:
| In many cases there is some opportunity to validate
| information before it goes out. In others ... not so much.
|
| Even a missile-launch alarm would typically have _some_
| opportunity to be assessed based on alert values (e.g.,
| increasing or decreasing hostilities), and perhaps multiple
| sensor systems (boost-phase IR tracks plus radar
| signatures, known planned non-military launches, etc.).
|
| In the case of earthquakes, their very unpredictability,
| the brief period of time avialable in which to _make_ an
| alert (often only a few seconds, in cases a few minutes)
| means that manual cross-validation is all but impossible.
| Still, checks across multiple seismic detectors, preferably
| isolated from one another to the maximum extent possible,
| would be one potential check, though you 'd still need to
| have multiple sensors relatively close together, as the
| time of propagation of seismic waves is both what provides
| the early alert _and_ causes the damage. (Relative speeds
| of P (primary) and S (secondary) waves helps --- the p
| waves tend to cause less damage, but provide an earlier
| alert, the s waves arrive more slowly but do most of the
| damage.
|
| At the surface, speed differential is about 3 km/s, meaning
| there's roughly 1 second of arrival differential for each
| 3km the observer is from the epicentre. (Subsurface waves
| travel faster.) Each 3km of separation of seismic stations
| costs 1 second of advanced warning time, plus whatever
| system logic and response times exist.
|
| But given that major earthquakes can occur suddenly and
| without warning or pre-shocks, you really do pretty much
| have to be ready for anything at any time. And alerting
| systems need to take this into account. One option might be
| to have the logic on the phone itself --- it would trigger
| an alert, but only if some number of independent alarms
| were detected. One would be unlikely to trigger a false
| alarm, but two or three near-simultaneous alerts would
| indicate a major quake.
|
| Penalising false alarms is probably the wrong approach. An
| engineering philosophy, of determining paths to either
| false positives or false negatives (each of which have high
| impact), and eliminating those.
| jcrawfordor wrote:
| Often these false alarm incidents occur due to issues
| with the "last mile" of the system in the US, which might
| be substantially alleviated if there was a federal effort
| to get automation in place. In a nuclear strike, for
| example, NORAD would issue the alarm ("attack warning")
| via FEMA NAWAS and EAS after several documented and
| proceduralised validation steps.
|
| The problem is that after FEMA NAWAS delivers the alert
| (audibly) to state and local EOCs, the next step is a
| ???. In those areas that do have some type of state or
| locally operated warning system, it's usually just some
| staff member pushing a button... and the button pushing
| is where mistakes can and do get made. In theory IPAWS
| and CAP will introduce automation at this step, but
| there's a lot of issues that have made CAP implementation
| slow, mainly the budgetary limitations of local
| governments and the fact that the major IPAWS/CAP
| software vendors expect very high prices.
|
| Obviously in the case of earthquake warnings the options
| for manual validation are very limited due to the time
| constraints... but in general false-positive incidents
| have come from fat fingering, not misidentification by
| technical systems. There are good opportunities to put
| safeguards in place for automated systems to reduce false
| positives. For example (although I believe this is partly
| manual), as I understand it the Pacific Tsunami Warning
| Center will not issue a full warning until multiple data
| buoys have indicated a tsunami wave. That doesn't
| guarantee that it will be of damaging proportions once it
| reaches our coasts due to the vagaries of ocean modeling
| (i.e. in the case of the major Japanese earthquake in
| which a tsunami did occur but was quite small by the time
| it reached Hawaii, so the warnings felt a bit silly), but
| it does ensure that it's not an outright false positive.
| teitoklien wrote:
| > there should be penalties for false alarms like this
|
| I'd rather have a false alarm about a dangerous event. Then
| a missed alarm for the event.
|
| Especially if the false alarms are very rare.
| olivermarks wrote:
| @tulsigabbard has a lot to say about this.
| https://abcnews.go.com/Politics/hawaiis-panic-missile-
| alert-...
| bagels wrote:
| The problem is that if the frequency of false alarm is
| high enough, people ignore the real ones. There is also a
| problem where the alarm causes harm or causes people to
| unintentionally become harmed.
| Vedor wrote:
| In Poland, it was common to use alarm sirens on the
| occasion of national holidays, even the less important
| ones. I was so used to meaningless alarm signals that
| hearing one was making me wonder what anniversary it was,
| instead of thinking about the potential dangers.
|
| I'm not sure if it was a nationwide problem - voivodes
| (provincial govenors) could arbitrarily decide on the use
| of such a signal to commemorate important events. Maybe
| it changed since then.
| letitbeirie wrote:
| Apparently there was actually a point in time like they
| talk about in driving school, when a honking car horn
| meant "watch out," not "fuck you."
| s5300 wrote:
| I have a friend who was stationed in Hawaii during that
| alarm. He is fairly high up in naval ranking.
|
| We met through an extreme sport hobby in which there are
| personal speed records to set, and setting those past a
| certain point are quite dangerous to ones body/life. He and
| I were both past said point back then.
|
| He was living alone at the time and was woken up by the
| alert. Through his mind went "either this is a false alarm,
| or I am completely fucking dead and there's nothing I can
| do about it"
|
| Did absolutely nothing except put on his gear & went out
| and set a new speed record far into the "one fuckup and
| you're severely injured or dead category"
|
| Fun times.
| lisnake wrote:
| well, I have to ask what is that sport
| L_226 wrote:
| could be downhill skateboarding -
| https://www.youtube.com/watch?v=vSBcrmx4aFw
| bonestamp2 wrote:
| I don't know, but my guess would be "free soloing".
| Basically, climbing up a rock face with no safety
| equipment. Enthusiasts keep track of speed records for
| popular climbs. Records are often proven with personal
| gopro footage, eye witness, etc.
|
| https://en.wikipedia.org/wiki/Speed_climbing#Free_soloing
| dillondoyle wrote:
| I wonder what 'personal' means in his context though. A
| lot of the big speed runs, el cap, that face in squamish,
| are pretty established and not a super personal
| experience, like say picking your favorite one pitch and
| doing it.
|
| But I am shocked at how many climbers I know who free
| solo more than 40 feet off the deck...
| davidchen wrote:
| If I had to warrant a guess I'm gonna say it's wingsuit
| flying. I can imagine his friend living at the top of a
| mountain putting on his squirrel suit to get one last
| glimpse of Hawaii before shit hits the fan.
| Hallucinaut wrote:
| You don't go for speed when flying a wingsuit and there's
| comparatively little you can do to change your speed, so
| this isn't likely the answer.
| buryat wrote:
| I got goosebumps reading your post and seeing the screenshot.
| I used to live in a seismic active region and experienced a
| few 6.0 and understand that a 9.0 is an end of the world
| event.
| thangalin wrote:
| https://en.wikipedia.org/wiki/Richter_magnitude_scale
|
| "9.0 and greater. At or near total destruction - severe
| damage or collapse to all buildings. Heavy damage and
| shaking extends to distant locations. Permanent changes in
| ground topography. One per 10 to 50 years."
| rmason wrote:
| Most you weren't alive then but Alaska had a 9.2 earthquake
| in 1964. I well remember the news accounts. Luckily not
| that many people lived in Alaska at the time. I cannot
| imagine if a quake of that magnitude hit modern day San
| Francisco.
|
| https://en.wikipedia.org/wiki/1964_Alaska_earthquake#:~:tex
| t....
| AmVess wrote:
| I got my first tornado alert in last week's outburst of
| tornadoes in the midwest.I wasn't worried about it until the
| tornado sirens started going off. I became quite concerned when
| I saw the clouds. I'd never seen them so low and moving so
| fast. 24 confirmed tornadoes!
|
| Luckily, they were no where near as powerful as the ones that
| KY got earlier this month, but it was still alarming.
|
| And then the geniuses decided to do a test of the system
| yesterday at 11PM.
| db65edfc7996 wrote:
| Even if you had been given 60 seconds warning, what kind of
| mitigation can you do for a magnitude 2,4,6? Is there anything
| to be done if you are walking on the street/in a car/in a N
| floor building?
|
| I do not live in an earthquake prone region, so trying to
| understand the rationale. With tornadoes, theoretically you
| could move to a structurally sound room, but I am unsure if
| there is any such thing to be done for an earthquake.
| 317070 wrote:
| You are doctor and you are just about to put an injection
| when you get the message.
| cutemonster wrote:
| Or in a car: Stop the car.
|
| And indoors:
|
| - Drop down; take cover under a desk or table.
|
| - Stay away from bookcases or furniture that can fall on
| you.
|
| - Stay away from windows. Glass may shatter from the
| shakings
| russdill wrote:
| Occasionally I need to work in the attic, on a ladder, etc.
| It'd be really good to know that everything around me is
| about to move.
| rich_sasha wrote:
| I understand you can hide under a table (won't help if the
| building collapses but you won't be whacked in the face by a
| bottle or bookshelf flying through the room), stand in the
| doorframe (these offer some protection AFAIU if the building
| gets damaged, or even run out into the open space.
| bsder wrote:
| > what kind of mitigation can you do for a magnitude 2,4,6?
|
| Simply walk outside? If you have an empty area nearby that's
| an extremely safe spot to be in an earthquake.
|
| If you're in a car, get out from an underpass? A lot of
| deaths were due to a freeway overpass pancaking in SF.
|
| Open your garage door? This is one of the big things that is
| supposed to happen in California. Fire departments are
| supposed to have an automated system that pops the garage
| doors when there is an earthquake so the trucks don't get
| trapped by bent doors.
| boznz wrote:
| I would think with a million cellphones with sensitive
| accelorometers you could get the data much quicker and much more
| accurate (a million+ data points gives you a lot of options)
| caleb-allen wrote:
| That's exactly what this app from UC Berkeley does
|
| https://play.google.com/store/apps/details?id=edu.berkeley.b...
| axiosgunnar wrote:
| Sounds like a privacy nightmare
| bsmith0 wrote:
| https://en.wikipedia.org/wiki/Differential_privacy might help
| varajelle wrote:
| What was the exact message sent?
| mwattsun wrote:
| I lived through the 1989 Loma Prieta earthquake near the
| epicenter in Aptos California. My house suffered extensive
| damage. I think 3 people total were killed in Santa Cruz. One was
| standing next to a brick building and the other was next to a
| horse that bolted. A 10 second warning probably would have saved
| their lives, if they were prepared to take action when they got
| it. On the other hand, I don't think a 10 second warning would
| have done me any good. It's a great technology though.
| not2b wrote:
| The largest number of deaths (42) came from the collapse of a
| double decker freeway structure in Oakland. It would have been
| much worse if it weren't for the baseball championship game
| that got many people watching the game instead of driving home.
|
| I was in grad school at UC Berkeley and living in San Francisco
| at the time. Fortunately I left early that day, since BART was
| stopped and the Bay Bridge was impassible after the earthquake.
| peter303 wrote:
| No smartphones then, though there was a rudimentary internet. I
| had to ftp earthquake from the USGS because the web had not
| been invented yet.
| clsec wrote:
| yeah, I don't think a 10 second warning would have done
| anything other than get me outside.
|
| As it was, I dropped the bag of garbage I was just about to
| take out, saw the corner of the living room in my second story
| wood frame apartment in Mountain View move 2 feet in each
| direction, and tried to get outside. That was unsuccessful
| because everything in my hallway closet flew out and blocked
| the front door. So I headed to my bedroom and dove into the
| closet filled with dirty clothes. I remained there safely until
| it was over. Which was probably safer than going outside with
| exploding transformers and sketchy power lines.
|
| Someone else commented on wanting to feel a smaller quake. As
| someone born and raised in CA I used to love feeling
| earthquakes. I thought they were fun! That was until Loma
| Prieta, where I honestly thought I was going to die.
| ec109685 wrote:
| Or more people would have ran out of the house and gotten hit
| by falling debris as they fled their house. It's hard to act
| rationally in that situation.
|
| I went through all the duck and cover drills through school,
| and when the house started shaking, I bolted out of there
| during that earthquake.
| xattt wrote:
| It's an interesting test of people's situational awareness:
| what am I near right now that has the potential to kill me in
| an earthquake?
| mattlondon wrote:
| From TFA: "up to 10 seconds warning"
|
| Probably a usable amount of time I guess - I expect it probably
| takes 2 or 3 seconds to fully comprehend, then that leaves 5
| seconds or so to take cover.
|
| From someone living in UK where earthquakes are rare and tiny,
| what sort of cover can you take in less than 10 seconds? Go jump
| in a steel bath tub or something? Stand in a doorway? (Is that a
| thing? Does it depend on wood Vs brick Vs concrete?)
| Stevvo wrote:
| One advantage is to make it clear to you what is going on. Many
| people don't initially understand what they are experiencing as
| earthquake the first time it happens. Everything shaking is so
| far removed from any other experience that you might think
| 'wow, that's some really strong wind' because that is the
| closest reference your brain has for the situation.
| jconnop wrote:
| The advice we get in New Zealand is to get underneath something
| strong like a table. Sitting where I am now I could probably
| make it under a table in under 5 seconds.
|
| The bigger effect maybe is that prepares you mentally for the
| impact, so you're already planning your next steps and aren't
| in quite as much surpise/panic as if you had no warning.
|
| When things are collapsing, seconds can be the difference
| between life and death. Even if a system like this only saves a
| few extra percent of lives lost in a major earthquake, it
| sounds worth it to me.
| yosito wrote:
| > The advice we get in New Zealand is to get underneath
| something strong like a table
|
| Depending on how earthquake-proof a building is, this could
| be bad advice. If you're in an earthquake-proof building, a
| table will protect you from falling objects. If the building
| you're in collapses, you'll want to be _next to_ something
| that 's not very compressible, like a bed or a couch. The
| collapse will leave open triangles next to objects like this,
| which are the best place to survive a collapse.
| tempnow987 wrote:
| Your elevator stops at next floor and doors open.
|
| You grab your child practicing their walking skills on a
| dangerous edge.
|
| I just get up and stand in a doorway away from the unsecured
| bookshelves.
| indigomm wrote:
| We get more than people think in the UK [0], but nothing to
| worry about - a mouse fart compared to Japan, West Coast, etc.
|
| [0] https://earthquakes.bgs.ac.uk/education/faqs/faq6.html
| bsder wrote:
| Bad earthquakes aren't short. They can go on for several
| minutes.
|
| I'm not going to interrupt may day for a 4.0. For a 6.0+, I
| will probably turn off anything on the gas stove and walk
| outside if I can.
| SeanA208 wrote:
| I'm surprised this xkcd hasn't been shared here yet. Highly
| relevant: https://xkcd.com/723/
| digitallyfree wrote:
| While mobile alerts are great, I wish there was a way to
| (voluntarily) get those official warnings via other means like
| (landline) phone call, SMS, or email - in cases where you may not
| have your phone on you or if there is no service.
| seidoger wrote:
| I don't know if that's everywhere in Japan but in 2014 I was in
| Tokyo having lunch outside when suddenly this fast alert (ie.
| not a slow siren) started blaring, 5 seconds later the ground
| was shaking.
| dragonwriter wrote:
| > I wish there was a way to (voluntarily) get those official
| warnings via other means
|
| Mobile alerts are the most recent addition in the US; they are
| also carried by radio and TV broadcast, Cable TV, and a variety
| of other mechanisms. But not POTS,SMS, or email.
| therealdrag0 wrote:
| Have you checked your local government services? Some have
| emergency alerts via sms. Not sure if earthquake maybe be
| included.
| akyoan wrote:
| I'm not sure if SMS and email are ever considered urgent enough
| for this purpose. The alert is sent out _seconds_ before, it 's
| either a loud and unusual sound or you might get to read/answer
| _after_ it actually hits.
|
| i.e. it'd be useless.
| Lammy wrote:
| > "We got some reports from folks that they got up to 10 seconds'
| warning before they felt shaking. That's pretty darn good," said
| Robert de Groot, a ShakeAlert coordinator with the USGS.
|
| Fun fact: that's three times longer than it takes to safely trip
| a nuclear reactor: "A reactor trip causes all the control rods to
| insert into the reactor core, and shut down the plant in a very
| short time (about three seconds)." https://public-blog.nrc-
| gateway.gov/2012/12/28/what-is-a-rea...
|
| I mention this because this quake's epicenter is pretty close to
| the Humboldt Bay NGS, and there's always a lot of uninformed
| hand-wringing about atomic energy near fault lines (even though
| this particular station has been offline since 1988)
| https://en.wikipedia.org/wiki/Humboldt_Bay_Nuclear_Power_Pla...
| mpyne wrote:
| I'm a nuke proponent but it's very worth pointing out that a
| nuclear reactor that has been recently shutdown will need days
| of cooling to be available in order to safely avoid damage to
| the reactor and potential meltdown, pressure spikes, etc.
|
| New-ish designs can do the cooling completely passively but not
| all active nuclear reactors are so equipped (Fukushima's
| Daiichi's ancient BWR design needed active cooling, which
| failed in the tsunami, while the slightly newer BWR design at
| Fukushima Daini survived the tsunami damage without further
| core damage).
| outworlder wrote:
| It's also worth noting that, in the case of the Fukushima
| accident, all nuclear reactors shutdown correctly when the
| earthquake was detected, before it reached the plants. All of
| them, including the affected plant, shutdown as designed. Then
| the tsunami came and created a bunch of issues (lots of vital
| equipment at ground level, generator trucks came and were
| incompatible, yada yada yada).
|
| Japan has a great early warning system for both earthquakes and
| tsunamis that has been in operation for quite a while now(since
| 2007?)
|
| https://www.youtube.com/watch?v=lAxxZkpV0HI&t=62s
| ralph84 wrote:
| In California is there a way to configure an iPhone so you get
| earthquake alerts but not covid alerts?
| djrogers wrote:
| I'm not sure where you're getting your COVID alerts from - I
| live in California and have never seen one. Maybe you installed
| an app?
| tedunangst wrote:
| https://www.mercurynews.com/2021/11/16/san-jose-officials-
| ar...
| ralph84 wrote:
| Santa Clara county. Every time there was a new health order
| or vaccine availability change they sent an alert. Not from
| an app. On iPhone the options are amber alerts, emergency
| alerts, and public safety alerts. The question is what combo
| of those if any will give you real emergencies and skip the
| custody disputes and covid noise.
| Miiko wrote:
| San Mateo county. Have all alerts enabled in my iPhone and
| never got any covid-related or custody dispute alerts. You
| probably either have some app installed or enrolled in some
| service.
| ralph84 wrote:
| Your county health officer and my county health officer
| have had quite different takes on covid.
| Rebelgecko wrote:
| iOS probably lets you uninstall the California contact tracing
| app, that should stop the alerts
| mongol wrote:
| Does it sound different than other sounds a phone usually makes?
| I imagine that unless it is carefully designed, the reaction
| could be "what is that"?
| Havoc wrote:
| Another poster above describes the sound as obnoxious so
| presumably not the normal ones
| anticensor wrote:
| No, usual notification sound, cannot be DNDd but can be
| silenced by setting the default notification tone as silent.
| AnssiH wrote:
| According to a graphic in the OP article there are different
| types of mobile alerts depending on the earthquake strength,
| only the strongest ones triggering an actual Wireless
| Emergency Alert.
| teeray wrote:
| On iOS, these alerts mimic SAME tones[0]. It sounds like a
| brighter version of the combined attention tone with a bit of
| modulation.
|
| [0]
| https://en.wikipedia.org/wiki/Specific_Area_Message_Encoding
| JetAlone wrote:
| Pretty good design predilection nonetheless. The one in Japan
| is very distinctive.
| tkgally wrote:
| I don't know what it sounds like in California, but in Japan,
| where I live, it's unmistakable: a very loud buzz followed by a
| female voice saying firmly--in Japanese, at least on my phone--
| "It's an earthquake," repeated over and over.
|
| I've experienced it maybe a dozen times over the past ten
| years. (I've felt earthquakes much more frequently here than I
| did in California, where I grew up.)
|
| Two or three times it has woken me up in the middle of the
| night, and I was able to get up and move away from the dresser
| that's right next to my futon and could conceivably tip over on
| me. (I shouldn't be sleeping there, I know.)
|
| Several times I was near other people--on a commuter train, in
| a meeting, walking along a sidewalk--when multiple phones
| sounded the alarm at the same time. Once or twice, I've been on
| a train that stopped suddenly with an automated announcement
| coming over the loudspeaker saying "Emergency stop!
| Earthquake." Once I felt fairly strong shaking after the train
| had stopped, so the advance warning might have prevented a
| derailment.
|
| Maybe half the time no perceptible shaking has followed the
| alert, either because I was too far away from the affected area
| or because it was a false alarm. One such false alarm occurred
| on July 29, 2020, and the Meteorological Agency issued an
| apology [1, in Japanese]. There have also been at least a
| couple of strong earthquakes where the system didn't go off
| when it was supposed to, so it's not yet perfect.
|
| The alerts are startling but also reassuring. It's much better
| to have a twenty-second warning than none at all.
|
| [1] https://digital.asahi.com/articles/ASN7Z4631N7ZUTIL01Z.html
| gwbas1c wrote:
| > One such false alarm occurred on July 29, 2020, and the
| Meteorological Agency issued an apology
|
| That's so important for emergency alert systems:
| Acknowledgement that false alarms are disruptive and
| apologizing for the stress that they cause.
|
| After being woken up in the middle of the night for an
| unjustified alarm I proactively turn off all emergency alarms
| on my phone. If, in the morning, all the headlines were about
| an apology, I'd keep the alarm on.
| iszomer wrote:
| Here's a good visual representation of their early warning
| system back in 2011..
|
| https://www.youtube.com/watch?v=n-FMpNBfna8
| UsernameChoice wrote:
| Interesting. As someone who watches the live seismic data in
| Japan from the US, I would have thought it'd be the nice
| sounding chime that they play on TV stations. Then again,
| it's a phone, so buzzing is definitely a go-to solution for
| notifying the people in the vicinity.
| goodcanadian wrote:
| _There have also been at least a couple of strong earthquakes
| where the system didn't go off when it was supposed to, so
| it's not yet perfect._
|
| Obviously, I don't know the exact details of those incidents,
| but if the epicentre is too close to you, there will not be
| time for the alert to occur. The alerts work because the
| earthquake travels slower than the telecommunications
| signals. No alert can be triggered until after an earthquake
| has occurred. Then, however, a warning can be sent to notify
| people further away from the epicentre before the shaking
| reaches them.
| not2b wrote:
| Yes, the further you are from the epicenter the more time
| there is for a warning, but it doesn't rely on having a
| detector right at the center. That's because there are two
| sets of seismic waves that travel at different speeds. P
| waves arrive first; S (shear) waves cause most of the
| damage. Of course, electronic signals travel much faster
| than either.
| EE84M3i wrote:
| In the large earthquake in Tokyo in October, I felt the P
| wave, then got the alert on one of my phones, then the
| s-wave hit and I got the alert on my other phone
| (different provider). Interesting seeing the race, and I
| wonder how optimized notification systems are.
|
| [1]:
| https://en.m.wikipedia.org/wiki/2021_Chiba_earthquake
| mensetmanusman wrote:
| Sounds like you could give people ptsd if you made that your
| ring tone.
| sirn wrote:
| This[1] is how it sounds in Japan if anyone is interested.
|
| The author of the sound (Kokubo Takashi) interviewed in the
| past[2] that he designed the sound to make people alerted,
| but it must not make people feel uneasy or causing panic. The
| sound must also not resemble any other alert sound as people
| may ignore it. The result is what we're using in Japan today,
| repeating three times to ensure it draws enough attention.
|
| [1]: https://www.youtube.com/watch?v=0DGAuxO_YWE
|
| [2]: https://news.livedoor.com/article/detail/6419314/
| quartesixte wrote:
| Someone needs to tell the North American market to not make
| everything the same tone. The alerts in California are
| almost completely ignored now because they use it
| constantly for Amber Alerts/Silver Alerts.
| jcrawfordor wrote:
| I have long complained that "amber alerts," "silver
| alerts," and in some states "blue alerts" have seriously
| degraded the value and functionality of these alerts
| through desensitization. The original design goal that
| lead, through many evolutions, to EAS/WEA/IPAWS/etc, was
| an alert system that would cause the public to take
| organized, pre-planned steps within _30 seconds_ of the
| issuance of the alert [1]. While we no longer worry about
| nuclear attack on such a short timeline, earthquake early
| warning has once again highlighted the requirement for a
| system that is _immediately recognizable as requiring
| protective action._ Overloading EAS with these types of
| messages, while politically appealing, has effectively
| eliminated the ability of the system to demand an
| immediate response. This will, ultimately, endanger
| lives.
|
| Ultimately, nothing should be issued via EAS that does
| not require _prompt and decisive action._ This is not an
| exotic category: tornadoes, flash flooding, large hail,
| tsunamis, earthquakes, and civil and industrial
| emergencies are all reasonably frequent real-world events
| in which prompt and decisive action by the public saves
| lives and property. Unfortunately we have completely
| tangled them in with "a child was abducted, or a senior
| citizen wandered, or a cop was shot somewhere in the
| state," a scenario with no generally understood action
| for the public. That information should be disseminated
| using means other than the distinctive EAS attention tone
| which has always been intended to be reserved for those
| situation in which you must act immediately [2].
|
| This doesn't mean a return to the old situation in which
| only POTUS was authorized to issue emergency messages,
| but it should mean that emergency message issuance is
| limited to scenarios that meet the same general criteria
| of requiring immediate action, regardless of their
| originator. The NWS and state governors (really their
| EOCs) do produce such alerts, but they should receive
| specific criteria to require.
|
| [1] It had been determined in the 1950s that action
| within 30 seconds would produce substantial (e.g. 70%)
| reduction in fatalities in the case of an unanticipated
| nuclear attack, but that warning greater than 30 seconds
| was not always feasible. Improved early detection systems
| such as OTH radar have made this issue somewhat obsolete,
| although more recent developments such as HGVs and
| nuclear-armed "sea drones" like Kanyon have potentially
| brought it back to relevance even just in the case of
| nuclear war.
|
| [2] Really the attention tone is a leftover technical
| detail from an earlier implementation, but its use has
| been specifically protected because it is so well
| recognized by the public as an indication of a national
| emergency. Unfortunately that protection is at the whims
| of legislators which frequently expand it to include
| whatever is politically appealing, regardless of actual
| outcomes.
| MisterTea wrote:
| > ... I was able to get up and move away from the dresser
| that's right next to my futon and could conceivably tip over
| on me. (I shouldn't be sleeping there, I know.)
|
| There are restraints you can buy that attach furniture to the
| walls with a strap. I know its sold to prevent children from
| attempting to turn their dresser drawers into a set of steps
| which when climbed tips over on top of them.
| dmurray wrote:
| Even my cheap IKEA bookcase came with a strap and a mount
| point for it. I think it would withstand a moderate
| earthquake, but not necessarily a child applying that level
| of leverage.
| lostlogin wrote:
| It's worth doing. A baby was killed by a toppling tv here
| in New Zealand during the Christchurch earthquake.
|
| https://www.nzherald.co.nz/hawkes-bay-
| today/news/christchurc...
| zikduruqe wrote:
| https://www.charlieshouse.org
|
| And it saves lives too.
| tjpnz wrote:
| A couple of months ago I was walking through a park late at
| night thinking I was alone. So it was a rather surreal
| experience to see phones light up everywhere around me with
| that woman's voice speaking in almost perfect unison.
|
| In this particular case there was a 2-3 second warning. Was
| one of the more violent ones Tokyo has had recently and I was
| rather glad to not have been inside.
| nend wrote:
| Ever receive a flash flood warning, severe weather alert
| (lightning, tornado), or amber alert on your phone? It'd be the
| same notification. I'm sure there's others too, those are just
| the ones I've received before.
| bombcar wrote:
| I'm so glad apple separated amber alerts from the emergency
| broadcasts. Used to get two or three a week which made it
| completely useless.
| xeromal wrote:
| On Android, I've unsubscribed from everything except
| presidential alerts.
|
| I had my last straw when I started getting alerts for wear
| a mask and other ridiculous crap.
| lostlogin wrote:
| I've been a supporter of the government campaigning and
| messaging here in New Zealand. However if this was
| happening I'd be most unhappy.
|
| It's close to the Orwell '2 minute hate'.
|
| https://en.m.wikipedia.org/wiki/Two_Minutes_Hate
| xeromal wrote:
| Yeah, the original idea was excellent. Great for warnings
| or child abductions but now even the child abduction
| stuff is annoying. Some parents battling over the custody
| of their kids is now a child abduction
| MerelyMortal wrote:
| It would be really nice on Android if I could get the
| alerts without the obnoxious noise.
|
| Since the noise and the alert are tied together, and I
| absolutely detest the noise, I have the alert turned off.
|
| It's silly that you can turn off the ring for a phone
| call and still get the notification, but can't turn off
| the alert noise without also turning off the alert
| notification.
| xeromal wrote:
| Yeah, it's supposed to be grating because it's a rare
| even but sending daily covid advice is honestly a waste
| of a good system.
| dylan604 wrote:
| I have mixed feelings on Amber Alerts. I'm in Texas, and I
| receive alerts for things that are happening so far away
| from me, that most states could fit inside the distance
| apart. Seems like there should be some sort of max distance
| away for the alerts to be issued.
|
| I've also wondered if useable information has been received
| from these alerts, or if it's just a bit of psychology
| being used against the perps when the alert about them goes
| off on their phone.
| opwieurposiu wrote:
| The majority of amber alerts are from parents in custody
| disputes. Mom says dad stole the kids or visa versa. They
| really should not be putting these cases into the same
| category as abductions.
| dylan604 wrote:
| There should be a fine for this. I understand that there
| are situations where a parent does take their kids where
| it would actually fall under abduction/kidnapping.
| However, if parents are abusing the alert system for
| minor custody disputes, then this should be handled with
| a severe punishment. Almost to the point of losing the
| custody battle if they're that immature.
| dzdt wrote:
| The alerts are sent by police, not parents. I was curious
| and at one point went thru a year's records for NY state
| amber alerts. There were zero instances of stranger
| abduction. Most cases are as you say children taken by
| parent without custodial rights, with a secondary set of
| teens running away, sometimes with an older romantic
| partner.
| jeromegv wrote:
| Depends on the jurisdiction. In Canada, it's all the same.
| scohesc wrote:
| It's absolutely crazy that whoever decided to create the
| warning system in Canada decided to roll "amber alerts"
| and "presidential alerts" into the same alert. So now I
| can get woken up in the middle of the night for an alert
| for a lost child hundreds of kilometers away that I can't
| do anything about - and, even if I turn off amber alerts,
| they still come in as a presidential message.
|
| This has happened numerous times.
| reaperducer wrote:
| If I lived in Canada and got a presidential alert, I'd be
| pretty alarmed. If I got a prime minister alert, less so.
| ALittleLight wrote:
| Can't you turn off Presidential alerts?
| xxpor wrote:
| No. It's the one level you can't turn off.
| dtech wrote:
| Android's Emergency Broadcast is very loud and distinctive, my
| country tests periodically.
|
| I'm not sure if seconds before impact would be early enough for
| me to take action though.
| 323 wrote:
| Earthquakes tend to have a bit of a ramp up period (P wave vs
| S wave), I was in an earthquake once and could figure out
| initially what was going on, because I was experiencing the
| first low intensity waves. An alert would avoid this initial
| confusion.
| themodelplumber wrote:
| FWIW this recent quake triggered a pleasant bell-chime sound on
| my Android phone. I hadn't heard that particular sound before.
|
| I appreciate that the warning gave me enough time to radio my
| kids in the house and let them know to expect something.
|
| We never felt the quake but it was good practice anyway.
| [deleted]
| robertlagrant wrote:
| The cause of the earthquake has been identified as all the phones
| simultaneously vibrating from a stress test of the alerting
| system.
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