[HN Gopher] 5.1 Magnitude Earthquake Near San Jose, CA
___________________________________________________________________
5.1 Magnitude Earthquake Near San Jose, CA
Author : mfiguiere
Score : 146 points
Date : 2022-10-25 18:50 UTC (4 hours ago)
(HTM) web link (earthquake.usgs.gov)
(TXT) w3m dump (earthquake.usgs.gov)
| s1mon wrote:
| I live in SF on bedrock, but on the 5th floor of a ~100 year old
| steel framed apartment building. Definitely felt it, but nothing
| like the 5.1 in 2001, when I was on the 11th floor of the old
| Hamm brewery building in SF. That swayed back and forth way too
| much for my taste.
|
| For the first few minutes a Google search for "earthquake"
| initially had it located some distance from "San Hose". Clearly
| someone was typing that it in manually.
| shriphani wrote:
| My garage door shook for a bit but I got none of these alerts.
| I'm on tTmobile, do I need to sign up somewhere ?
| oars wrote:
| What mobile device do you have?
| shriphani wrote:
| ios
| redwood wrote:
| I didn't feel it at SJC
| manofmanysmiles wrote:
| I barely felt it in Berkeley, and thought I was imagining it.
| baggy_trough wrote:
| Loma Prieta was preceded by two 5.x foreshocks within a year.
| [deleted]
| Sakos wrote:
| One in June, one in August, then Loma Proeta in October. Is
| seasonal weather ever a relevant factor for quakes?
| baggy_trough wrote:
| Seismologists believe not.
| jofer wrote:
| Put simply, no.
|
| The details are messier because groundwater flow very much
| does affect earthquakes (poroelasticity), but by and large,
| seasons don't affect groundwater flow significantly at the
| depths involved. E.g. wet vs dry weather doesn't matter. But
| on the other hand, a lake filling up or draining can,
| especially in terms of triggering very small earthquakes.
| guenthert wrote:
| First time I noticed vertical, not just lateral movement. 5.1
| isn't all that big, but this one was close to me. Good that the
| building is a wood structure, otherwise I'd be looking for damage
| now ...
| benlivengood wrote:
| I got an Android alert before the waves arrived in the East Bay
| (Oakland-ish) which is neat from an SRE perspective.
| mayli wrote:
| Got that too, but almost at the same time when I feed it.
| anontrot wrote:
| Stop feeding the Earth quake god damnit!
| baggsie wrote:
| That must be quite terrifying given the location - does the
| alert indicate the strength of the quake?
| s1artibartfast wrote:
| My alert indicated the magnitude and I received it before I
| felt the quake
| raggi wrote:
| My shakealert had a prediction of 4.9.
| outworlder wrote:
| It does not. Not even sure it's possible.
| not2b wrote:
| We have a demonstration that it is possible just today, as
| the people who got an alert also got an estimate of the
| strength. The broadcast estimates were slightly low: 4.8
| for a 5.1. But in the neighborhood.
| twawaaay wrote:
| This is actually excellent/impressive estimate.
|
| Remember, for this to be usable you need to start sending
| it out _BEFORE_ the actual earthquake ends at the place
| when it is first detected.
| kadoban wrote:
| Even if you could, not sure it'd be a good idea from a ux
| perspective.
|
| I'm thinking the more info you provide, the longer it takes
| the brain to process, and split seconds matter here.
| BitwiseFool wrote:
| I'd also say the average person has no intuitive sense
| for earthquake magnitudes and giving a somewhat precise
| number wouldn't affect their behavior the way a broad
| category warning like mild, moderate, severe, and
| catastrophic would.
|
| I suppose the people getting these notifications really
| just want to know if they should scramble for safety
| immediately.
| [deleted]
| wtvanhest wrote:
| I received the notification today for a 4.9 or something
| like that. It took me at least a half second to second to
| read the message.
|
| I agree with your point that the message should have way
| less info which could buy me additional time.
|
| Something like: 4.5-5.9: "Earthquake cat 1" 6.0-6.3:
| "Earthquake cat 2"
|
| Etc. something to tell me, get ready, or something to
| tell me this is going to be huge, but not precise numbers
| or even better:
|
| "Earthquake, 3.87 seconds" with a count down would be
| ideal. If I have 7 seconds I can get outside. 2 seconds
| and I duck and cover.
| jltsiren wrote:
| I got a notification (in Santa Cruz) that mentioned a
| magnitude (4.9), a distance (~30 miles), and that I
| should expect mild shaking. I saw the notification a few
| seconds after it arrived, because my phone was making a
| weird noise, and the shaking started immediately after I
| read the notification. It was probably the strongest
| earthquake I have experienced in the ~5 years here, but
| there were several similar earthquakes every year when I
| was living in Chile.
|
| If you send notifications for minor earthquakes like
| this, an estimate of the intensity is mandatory. At least
| in countries like Chile (and Japan?) where earthquakes
| are common. Otherwise people will learn to ignore them as
| false alarms.
| jofer wrote:
| It's highly imprecise, but not impossible. The alerts are
| already "this is over some threshold of ground
| acceleration", so there's an inherent severity estimate in
| the alert going out at all.
|
| But expected intensity information isn't included because:
| 1) it's still a very imprecise estimate at that time, 2)
| actual intensity of ground motion (what you care about)
| will vary dramatically by location, and 3) people don't
| deal well with that kind of information in an alert that is
| really meant to be "hey, take cover".
| Nuzzerino wrote:
| When I was working in SF (Near Montgomery BART), there
| was an earthquake, but I was at the dentist at the time.
| The dentist was nearby on a hill near Union Square. The
| earthquake was not felt at all there, but it was
| apparently rather strong at the office down the hill.
| [deleted]
| rconti wrote:
| predicted a 4.8 about 5-8sec before i felt shaking in redwood
| city.
| nonrandomstring wrote:
| How far are we from decent prediction?
|
| Many years ago ago I looked quite deeply at stick-slip friction
| models, the mathematics, dynamics and signals.
|
| I'd wager, in the time since 2005, there's a lot we could do with
| machine learning, predictive signal analysis and good historical
| data.
|
| Even 5 minutes warning could save a lot of lives.
|
| Any ML + geo-scientists on the case?
| daveaiello wrote:
| A seismologist from Berkeley said on KCBS that the ShakeAlert
| system worked in the case of this earthquake. So many people in
| the area were warned.
|
| I heard this on Audacy from the Philadelphia area.
| jofer wrote:
| ShakeAlert and similar systems are awesome, but not exactly
| what most folks mean by a prediction, FWIW. They're meant for
| warnings of seconds, but not for things on the scale of
| minutes or hours or days.
|
| Not to take away from ShakeAlert in any way though! Just
| clarifying that in terms of another comment I made about
| earthquake precursor signals.
|
| ShakeAlert and similar aren't about precursors, but instead
| are about "the earthquake has happened, let's tell folks
| before the damaging surface waves reach them".
| lazide wrote:
| Still better than a sharp stick in the eye!
| fragmede wrote:
| I mean, warnings of seconds is the best we can do right now
| but the goal is prediction. it's not a lot but it's enough
| to stop surgeries and trains.
| daveaiello wrote:
| Info on how ShakeAlert works: https://twitter.com/USGS_ShakeA
| lert/status/15849836003780321...
| jofer wrote:
| I really want to write up a long response to this... I used to
| be closely adjacent to this field, and I do ML work in other
| domains. ML is mostly irrelevant for this, though.
|
| Here's the short version:
|
| We're good at predicting where. We're still not good at when.
|
| Understanding what segments of a fault zone have built up the
| most elastic strain is something we're really quite good at
| these days. Given historical earthquake data, GPS measurements
| of deformation, and knowledge of the geometry and makeup of the
| subsurface, we can reasonably accurately model what segments of
| a fault are most likely to fail next. No ML needed or wanted.
|
| The issue with the "when" is what the precursor signals are.
|
| The precursor signals we're most likely to be able to reliably
| measure involve drilling down and putting sensors on both sides
| of the fault zone and measuring the sonic velocity across the
| fault zone repeatedly. As rocks or even a fault gouge begin to
| fail, they have to dilate slightly so that grains can rotate
| into position to slip (bad explanation, sorry). This dilation
| causes a drop in sonic velocity. Stresses on the rock mass as a
| whole also have velocity signals. Lab experiments have observed
| this fairly reliably. We've actually set things up to measure
| this in the field as well -- look up SAFOD. There were some
| likely precursor signals (a bit contentious, but it's fair to
| say there were interesting signals in the data). However, this
| type of instrumentation just isn't practical to deploy at
| scale.
|
| Other possible precursor signals involve hydrologic changes
| (e.g. well waters rising / changes in pore pressure) or Radon
| spikes, both due to the same dilation. Again, though, these are
| local effects and difficult to deploy a system to measure.
| (e.g. you need a deep borehole for the hydrologic changes, and
| the radon spikes are most reliably observed at depth as well)
|
| There is one more controversial category that is easily
| observable: ionospheric perturbations. GPS data is sensitive to
| the ionosphere, and one of the things you need to do in
| geodetic GPS station operations is correct for changes in the
| ionosphere. We tend to have tons of geodetic GPS stations
| deployed along fault zones. Folks have noticed some very
| interesting ionospheric perturbations before very large
| earthquakes. There have been a lot of papers published on this,
| but it's still not too widely accepted, last I checked. The
| proposed mechanism (piezoelectric effect and/or dislocation
| glide/creep building up charge) and the observed magnitude of
| change don't match. It also has only been documented as a
| precursor around very major earthquakes (which are rare) and
| only in retrospect.
|
| At any rate, tons of data don't help if it's all noise. The
| data that we think should have the most signal is _really_ hard
| to get. Things are still in the "promising, but a long ways
| off" state when it comes to predicting "when", and
| seismologists are _very_ careful to avoid doing work that could
| be taken as predictions due to past PR SNAFUs.
| s1artibartfast wrote:
| Are there any good maps or information on the energy stored
| in different specific faults and how much could be released
| when they go?
| nonrandomstring wrote:
| Lovely response, much more than I'd hoped for. Thank you sir.
|
| I suppose another issue that then arises, even if we did have
| decent prediction, is how to present and use predictive info.
| A "traffic light" system leading up to a countdown? How not
| to scare people, destroy economies with false positives and
| off-timing?
|
| A strange conclusion from my study (for sound) is that where
| eathquakes are concerned the next best thing to none at all
| is regular earthquakes.
| Enginerrrd wrote:
| Well, I'm not a domain expert here, but I have followed this a
| bit over the years. Here's my understanding:
|
| 1. Prediction actually is getting quite good, just not on the
| time scales that we're interested in, which would probably be
| somewhere between weeks and minutes.
|
| 2. I don't think that at the moment we have access to input
| variables with sufficient power to be predictive on those time
| scales. Right now, I think one of the best predictors of large
| EQ's on short time scales is a sudden increase in variance of
| seismic activity. Which is sort of obvious when you think about
| it... The best predictor of a big slip is when it's already
| started slipping.
|
| 3. There have been good gains on minute time scale warnings
| simply by using sensors and communication networks that can
| outpace the speed of the seismic waves. This can actually be
| incredibly helpful for seismic sensitive systems!
| jedberg wrote:
| If you felt it please fill out the USGS report:
| https://earthquake.usgs.gov/earthquakes/eventpage/nc73799091...
|
| Even if you didn't feel but live in the Bay Area please fill it
| out, they need that data too!
| yumraj wrote:
| Another one, 3.6 , few minutes ago
| daok wrote:
| South-East San Jose and I felt it. Received a notification on my
| Pixel phone as the house was shaking. Nothing broken, but for the
| 5-6 seconds it lasted I had the reflect to hold my monitors (on
| arms) because they were shaking.
| sizzzzlerz wrote:
| Was at lunch when it hit. I felt it sitting down at a table. I
| looked at others in the store and I didn't see anyone reacting to
| it at all. It was kind of subtle but it lasted for 5 or 6
| seconds. Just a little bit later, the earthquake reporting apps
| on my iPhone and iPad show a notification. Nearly 15 minutes
| after it happened, I get an alert on my phone from the state
| emergency services department reporting the shake. Quite useless,
| I'm afraid. A 5.1 is the largest we've had around here in
| sometime.
| yodon wrote:
| If you're close to the epicenter there's no way for any app to
| give you advance warning.
|
| Any app is going to make use of the fact that internet messages
| travel faster than earthquakes, so the farther you are from the
| epicenter the more warning you'll get. Close to the epicenter
| is going to be no warning regardless of whose app you use.
| raggi wrote:
| Was very disappointed that my iOS device had no alerting.
| s1artibartfast wrote:
| Android is partnered with Shakealert but Apple has not. There
| are third-party apps that you can get for iPhone.
|
| https://en.m.wikipedia.org/wiki/ShakeAlert
| raggi wrote:
| While I understand this in some sense, the efficacy of these
| systems going through the regular push message queue is going
| to be poor.
| tanseydavid wrote:
| Felt the first one in Central Marin.
|
| Today is actually the 33 year anniversary of the Loma Prieta
| quake -- weird.
| etrautmann wrote:
| That was one of my first memories and a totally wild experience
| as a young child in a hotel room on market st. I got to eat
| nothing but strawberry milk for about three days since since
| that was about all we could easily get, or so I remember.
| dumpHero2 wrote:
| Slightly off. That was on Oct 17, 1989.
| ChrisCinelli wrote:
| https://www.britannica.com/event/San-Francisco-earthquake-of...
| - It was Oct 17, 1989
| tjohns wrote:
| You can view a map here of how much advance warning people with
| ShakeAlert-enabled phones (like Pixel) got before the earthquake:
|
| https://earthquake.usgs.gov/earthquakes/eventpage/nc73799091...
|
| Santa Clara had 2 seconds of advance warning, and Sunnyvale had 4
| seconds. San Francisco got 18 seconds of warning, though was
| outside the "ground motion" zone.
| lazide wrote:
| I honestly thought it was someone rolling a big cart across the
| floor above mine. I was really surprised when I saw 5ish
| magnitude.
|
| Definitely worth checking the earthquake kit though!
| Exuma wrote:
| The Big ONEEEEEEE
| smcin wrote:
| It was not in the least terrifying and actually a big yawn; no
| known damage or injuries; "near San Jose" is inaccurate, it was
| 14km east of San Jose up the (fairly sparsely-populated)
| foothills near Alum Rock, 6.9 km depth, 37.311degN 121.677degW,
| inside Joseph D. Grant Park, zipcode 95140, total population only
| a tiny 191. So, remote, not urban and nothing like all those San
| Andreas movies. We felt the floor ripple for a couple of seconds
| and that was all. All transit is still running, just at reduced
| speeds (standard practice just in case there's a big aftershock,
| which there almost never is).
|
| You want to worry about something that's actually broken, then
| worry about whether the US MNT will get it together to call up
| leading goalscorer Jordan Pefok by 13 Nov deadline for the World
| Cup. Now _that 's_ worth losing sleep over. Or worry about Cuba,
| Haiti, Puerto Rico reconstruction from Hurricane Ian; Cuba got it
| bad.
|
| USGS.gov has a page up near-instantaneously with the details
| including crowdsourced reports of perceived intensity by
| location, as they always do:
| https://earthquake.usgs.gov/earthquakes/eventpage/nc73799091...
|
| PPS: in that area, Mt Hamilton (4265') and Lick Mill Observatory
| are worth a visit. And over west in Menlo Park visitors can visit
| the USGS station for free, that's a very fun and educational
| thing to do.
| throw8383833jj wrote:
| who cares about a Football match, I'd rather hear about a
| earthquake.
| smcin wrote:
| You're intentionally misrepresenting me: I clearly said:
|
| > You want to worry about something that's actually broken,
| then worry about whether the US MNT... __Or worry about Cuba,
| Haiti, Puerto Rico reconstruction from Hurricane Ian; Cuba
| got it bad.__
|
| So, we already established within a handful of minutes that
| zero Californians were affected, but 12 million Cubans, or
| many thousands of Haitians or Puerto Ricans. Yet we're
| wasting time debating the California non-event instead of any
| other thing that actually matters. Or even, at absolute
| minimum, teaching people the technial literacy to quickly
| understand that the CA earthquake had no impact, and thus to
| resist sensationalism. It was extremely clear from the
| original that that was my point.
|
| To state the same point another way: even (say) tonight's
| Fetterman-Oz debate (PA Senate race) will have more permanent
| impact on people's lives. Or, Hurricane Ian. Like I said.
| mint2 wrote:
| This comes off a bit as minimizing/dismissing concern of the
| next big one, and also seems to be expressing disappoint that
| this one wasn't more exciting instead of being "a big yawn; no
| known damage or injuries."
| smcin wrote:
| Nonsense, I live in Silicon Valley for 23 years now, this has
| nothing whatsoever to do with "the next big one", today's one
| was purely a 5.1 in a remote sparsely-populated area up the
| hills inside a county park with no reported damage or
| injuries, population only 191 and they hardly even have any
| two-storey buildings inside the entire park, not that those
| were reported damaged either. By the way, IIUC from
| geologists it's actually good and healthy to have frequent
| small earthquakes to blow off pressure and avoid becoming the
| "next big one", hence today's non-event is good news not bad
| news. I actually showed you multiple ways to instantly read
| the USGS data (coords, intensity, depth, population, total
| lack of buildings higher than two stories) to understand that
| this was a non-event not the "next big one", not even in the
| neighborhood. Technical literacy matters, sensationalism
| seriously doesn't.
|
| Today's non-event was actually a Good Thing in that it also
| gives us yet another occasion to calibrate earthquake early-
| warning sensors, to stay prepared for any actual serious
| earthquake, which this wasn't.
|
| I also said nothing whatsoever about "excitement" or
| "disappointed", so do not misrepresent me. I did imply that
| media is increasingly sensational (which it is) and lazily
| skewed towards merely collating cellphone "eyewitness
| reports" from places with 4G coverage, without making any
| semi-objective comparison to the rest of the planet; and I
| correctly pointed out that zero people were affected here in
| SJ today whereas 11 million Cubans were affected by Hurricane
| Ian [0], to pick one obvious example. I also know some
| friends-of-friends whose house was severely damaged by the
| 11/2020 Marikina, Manila floods/Typhoon Vamco/Ulysses [1] (98
| deaths, 19 missing, 360K rescued, ~43000 houses damaged).
|
| Also, a magnitude 6.2-6.5 struck rural northern Luzon,
| Philippines earlier today [2], no reported damage or injuries
| [3], but noone's mentioning that.
|
| [0]: https://www.state.gov/u-s-support-for-hurricane-ian-
| recovery...
|
| [1]:
| https://en.wikipedia.org/wiki/Typhoon_Vamco#Philippines_2
|
| [2]: https://earthquake.usgs.gov/earthquakes/eventpage/us6000
| iwds...
|
| [3]:
| https://newsinfo.inquirer.net/1684866/magnitude-6-7-rocks-
| ab...
| mint2 wrote:
| From that It's clear you didn't intend to minimize
| earthquakes in general which is good, it was just a matter
| of not the best wording/phrasing.
|
| "Big yawn" is a loaded word: It was not in the least
| terrifying and actually a big yawn; no known damage or
| injuries; ...
|
| Dismissing earthquakes: nothing like all those San Andreas
| movies. ...
|
| Minimizing risk: in case there's a big aftershock, which
| there almost never is.
|
| Comparing earthquakes to sporting events: You want to worry
| about something that's actually broken, then worry about
| whether the US MNT will get it together to call up leading
| goalscorer Jordan Pefok by 13 Nov deadline for the World
| Cup
|
| Experts believe a major quake in the Bay Area is "likely"
| (>=6.7) by 2032 per the usgs
| smcin wrote:
| It was already clear from my first post; you could have
| simply asked questions, instead of claiming you knew my
| intent and posting wrong assumptions.
|
| The topic here was never "the next big one" or "major
| future event on the Hayward and San Andreas Faults for
| the next 30 years". If you want to start a separate HN
| thread discussing either of those, you're free to. This
| ain't it.
|
| I actually dug up the USGS report to cite the epicenter,
| depth, intensity to teach people here basic literacy to
| make them immune from sensationalist reports without
| context. I showed what zipcode was affected and correctly
| stated how its population is almost zero and has no tall
| structures. Hence, "big yawn" is not loaded, it's a 120%
| accurate characterization of an earthquake miles up the
| foothills inside a county park. I'm not going to
| misrepresent those facts. I can't see why anyone else
| would.
|
| Minimizing risk Correctly stating that the risk of
| aftershock on today's event was minimal, and even in the
| tiny likelihood there had been one, given the original
| 5.1 caused zero reported damage, a (say) 4.6 aftershock
| would likely cause... zero damage. Zipcode 95140 is not
| downtown SJ or SF or LA.
|
| To do otherwise would be to distort the facts on today's
| non-event into some emotionally-driven narrative that
| minimizes other actually serious events which actually
| resulted in deaths, injuries, destroyed houses, power
| outages; why should we distort the facts like that? It's
| actively harmful. Sure, people can be needlessly
| frightened by sensationalist media reports, while
| simultaneously ignoring other natural disasters which
| flattened countries. Surely that's a trend we should
| fight against, yes; not contribute to?
|
| > _Experts believe a major quake in the Bay Area is
| "likely" ( >=6.7) by 2032 per the USGS_
|
| That was never the topic of this thread, also many of us
| who already all knew that a decade ago. So why try to
| hijack this thread with that? By all means start a
| separate thread to discuss it, and I'll contribute
| constructively over there.
|
| Comparing earthquakes to sporting events Comparing
| distorted sensationalism around non-events, to other
| contemporary events, including other natural disasters:
| _" Or worry about Cuba, Haiti, Puerto Rico reconstruction
| from Hurricane Ian; Cuba got it bad."_ Even failing to
| accurately identify the epicenter, intensity and depth
| (facts which are typically available within a few minutes
| on USGS.gov) actively pander to that sensationalism; I
| posted them; you haven't discussed them once.
|
| To summarize: today's non-event in 95140 caused zero
| deaths, zero injuries and zero damage; compared to others
| that actually impacted people and continue to over a
| month later, like Hurricane Ian. The earthquake early-
| warning systems worked as intended and that experience
| makes us stronger for the future. (By comparison,
| PG&E-started fires and electricity outages have caused
| far more disruption this year than earthquakes (:zero),
| and again that's a major political issue currently in
| California, not this.) Almost any other minor media story
| is more worthy than this one, this in particular on a day
| with multiple huge stories (foreign and domestic) worthy
| of coverage. Pick any other story worth being covered
| more, to replace the US soccer one.
| eddsh wrote:
| Didn't feel it in Palo Alto but my wife did in Stanford. I've yet
| to experience one!
| mdon wrote:
| felt it mildly on California Ave, in Palo Alto.
| eddsh wrote:
| I'm on Middlefield road in midtown, weird you felt it and I
| didn't! Slightly closer to San Jose than you.
| chipx86 wrote:
| Alma in midtown, and it was pretty noticeable here. I'm on
| the second floor and for the first time in ages, I didn't
| think it was just Caltrain.
| gnicholas wrote:
| Interesting, we definitely felt it in Menlo Park. Perhaps being
| on the second floor made it more noticeable? What stood out to
| me was how long it was -- it felt like we were moving for 15-20
| seconds, though it could have been shorter.
| jmathai wrote:
| I grabbed my phone a few seconds after feeling the quake and
| Googled "earthquake in california today". I'm amazed that the
| earthquake showed up as the top result with an exact coordinate
| and magnitude.
| tsunamifury wrote:
| Those with pixel phones got notifications 10 seconds before the
| earthquake wave hit them.
| eins1234 wrote:
| My Samsung got the notification from Google too, so probably
| not a Pixel exclusive thing.
|
| Though I wish it would have overridden silent mode. 10s of
| advanced warning isn't all that helpful if I only find out
| about the notification 10 minutes later.
| modeless wrote:
| You just reminded me to go into my notification history and
| turn on "Override Do Not Disturb" for the earthquake early
| warning notification. I really like the notification
| history for that; you can go back to a notification you
| dismissed hours ago and edit its settings.
| eins1234 wrote:
| Was this under the "Crisis Alerts" category for Google?
| Going to set it for my phone too, even though this kind
| of thing really should be set to override do not disturb
| by default.
|
| Apparently my phone supports notification history, but it
| was also turned off by default... Bad defaults strikes
| twice in a row.
| modeless wrote:
| It's in Google Play Services under "Personal Safety". I
| wish there was an option for it to make noise despite the
| vibrate only setting as well.
| aidenn0 wrote:
| On my Android 11 phone the only thing under "Personal
| Safety" is "Silence notifications while driving"
| anarazel wrote:
| My notification arrived minutes late, interestingly.
| jedberg wrote:
| I'm guessing you're in SF or Oakland?
| mentat wrote:
| Seemed even a bit longer before that on the peninsula
| coastside. The whole thing felt magical, to even know that
| much beforehand.
| tjohns wrote:
| Depends on where in the Bay Area you were:
|
| https://earthquake.usgs.gov/earthquakes/eventpage/nc73799091.
| ..
|
| Santa Clara had 2 seconds of advance warning, and Sunnyvale
| had 4 seconds. San Francisco got 18 seconds of warning,
| though was outside the "ground motion" zone.
| rconti wrote:
| myshake pinged my apple watch while i was recording a cat.
| Cat definitely did not detect it before myshake, I don't
| think he even noticed it until the actual shaking.
| rbolla wrote:
| Is it true?
| floydian10 wrote:
| Obligatory XKCD: https://xkcd.com/723/
| baggy_trough wrote:
| That would depend on where they were.
| sosodev wrote:
| I believe can actually just type "earthquake" and it will show
| the same result!
| not2b wrote:
| My home office in Campbell (just south of SJ) is on the second
| floor so I got more of a shake than my wife downstairs got,
| though her MyShake app gave her a few seconds warning.
|
| For those not in earthquake country, this was a moderate quake,
| not big enough to cause damage other than maybe knocking
| something over right near the center. The epicenter was in Joseph
| Grant Park to the east of San Jose, near Mount Hamilton.
| ipnon wrote:
| If you want early earthquake alerts, the Governor's office
| sponsors UC Berkeley to make the MyShake app. This app could save
| your life!
|
| https://myshake.berkeley.edu/
| yumraj wrote:
| tried installing it on iPhone and set the HomeBase - keeps on
| crashing.. :(
| yodon wrote:
| Their servers are probably getting hammered. Try again
| tomorrow or in a few days.
| yumraj wrote:
| A lot of Earthquake insurance companies are _probably_ also
| getting requests for a lot of quotes. It 'll die down once
| people see the quotes, coverage and deductibles ..
| hujun wrote:
| similar experience here, the UI design is confusing, tell you
| to select an area but apparently you can't select/drag on the
| map, you can only typing the address then many times the auto
| complete doesn't work, and it seems you have to use the
| incorrect auto completed address...
| brewdad wrote:
| I was getting those errors too a few days ago when I tried.
| However, the app does show my correct location. It either
| actually went through despite the error or is getting
| location in some other way as a backup.
|
| Probably the latter since I think I did grant location
| privileges to the app.
| abc_lisper wrote:
| Multiple friends reported that it didn't give an alert. On the
| lookout for a reliable app - does any of you have suggestions?
| andirk wrote:
| City workers digging up the street today in front of my house in
| Berkeley. I thought they hit a pipe! Glad it was just a huge
| earthquake
| yumraj wrote:
| You felt it in Berkeley?
| kstrauser wrote:
| I felt it in Alameda. It wasn't strong, but was very
| noticeable.
| jorts wrote:
| Weird. I am also in Alameda and didn't feel it but my
| kitchen cabinet door was slightly tapping against the
| cabinet which caught my attention. This is on the east end.
| yumraj wrote:
| The quake was on Calaveras fault, near SE San Jose.
|
| So, I guess it traveled along the East Bay fault lines
| all the way to Alameda and Berkeley. I am just surprised
| it was felt so far for a 5.1
| josuepeq wrote:
| Got the ShakeAlert notification; but felt no quake. Nothing
| noticeable at all in San Francisco/Twin Peaks. It's all bedrock
| up here.
| lucb1e wrote:
| I didn't get any notification on my phone. How does it try to
| figure out whether you should get one? Do you need to turn on
| location services, have a cell tower connected, or is it
| detecting pre-waves (I really know nothing about earthquakes)
| using the accelerometer?
| s1artibartfast wrote:
| Do you have iPhone or Android? If iPhone, you need to download
| an app
| lucb1e wrote:
| I'm on Android but in Europe. Was just curious how it tries
| to determine this as I turned off automatic location
| uploading to google.
| raggi wrote:
| There are different systems. The more critical system in
| the USA, WEA is a mandatory (FCC rules) central system that
| most consumer devices and consumer networks take part in.
| The "last mile" technology varies by network type and
| version.
|
| The GSM lineage (including 4G, LTE, 5G) is implemented
| using cell broadcast which is a protocol data unit that
| solves for the one to many problem. Extensions added geo-
| fencing & geo-targeting on the client devices (device
| compares its idea of location to the incoming message), and
| also cell based routing optimizations network side. The
| cell broadcast part is technologically available
| ~everywhere as a result of broad GSM deployment, but
| whether it is integrated into an alert system is a
| jurisdiction issue. Sadly few countries (in the global
| scope) have the kind of power of the US or the EU to gain
| access to things like extended on device features.
|
| The app based systems are largely based on some form of
| location reporting and push messages which are far less
| reliable - one to one messaging systems (like Apple/Google
| push notifications) are physically impossible to scale for
| real time sub-second alerting in dense populations, given
| the bandwidth constraints of radio.
|
| CB is expensive at the radio tower, and can disrupt normal
| communications (potentially including emergency services
| communications) as such it's use is more limited than other
| solutions, for example in todays event it was only used in
| an area of about a 25km radius. To put this in some
| context, many folks commenting here, including myself still
| in the "felt it" areas were within a ~90km radius (SF is
| about 85km away from the center).
| s1artibartfast wrote:
| Notably, these earthquake alerts do not go through the
| WEA system or an app. Or at least they don't follow the
| normal w e a path from the cell tower. They go through
| the operating system itself which is why they are
| received on Android and not iPhone. Apple has not
| integrated the functionality into their operating system.
| With iPhones you can get third-party apps however.
| fragmede wrote:
| S-waves travel faster than P-waves, so USGS detectors listen
| for those in order to produce the warning.
| andrewinardeer wrote:
| Let's hope this is not a foreshock.
| sbuttgereit wrote:
| I felt in San Francisco. I was on the sixth floor of one of the
| buildings in Civic Center. The shaking was pretty mild (which I'd
| expect given facts of what happened), but the duration was rather
| longer than many of the smaller nearby quakes you're likely to
| feel.
| ksaj wrote:
| In Canada, we have mandatory Amber Alert notifications that
| affect all modern cell phones. It is _loud_ so you aren 't likely
| to miss it. These alerts cannot be muted, and require the user to
| acknowledge receipt or another alert will come shortly
| thereafter. This helps to catch people during alert time in case
| their phones are not on, or they're in the shower, or whatever.
|
| I am surprised California and other wobbly places don't use the
| same system, with the addition of quake and forest fire alerts.
| Everybody here knows the alert sound instinctively now, so even
| if you're in public and hear someone else's phone go off, we all
| know what it is.
| dry_soup wrote:
| Japan has had this for years, but California's app for this is
| still in beta IIRC.
|
| It's funny to me that one of the world's tech capitals has
| taken so long to get this rolling. To be fair, California
| doesn't have earthquakes as regularly as Japan (at least not of
| the same magnitude). I guess this is another symptom of our
| crumbling institutions in the US, we only get services quickly
| if there's a profit to be made. In the popular imagination,
| innovation is only the domain of private companies.
| s1artibartfast wrote:
| I for one hope they never make the obnoxious amber alerts
| impossible to disable.
| Rebelgecko wrote:
| We do have the same system, commonly used for Amber Alerts,
| Silver Alerts, Blue Alerts, fires, floods, COVID-19 lockdown,
| foreign missile tests, etc. However there's no mandatory ack,
| and except for "presidential alerts" they can all be turned
| off. That's what I did after I got woken up for an evacuation
| notice 20 miles away from me, feel back asleep, and got woken
| up again by the followup message 30 minutes later saying it was
| just a drill.
|
| Anyways, the wireless emergency alert system has like 5-30s of
| latency. I suspect that might be enough to make push
| notifications a better solution. There's a # of apps taking
| that approach (full disclosure, my employer makes one of them),
| I think they all ingest data from a private USGS Kafka server
| hot_gril wrote:
| I don't recall ever getting alerts for earthquakes, though.
| hot_gril wrote:
| I've also heard Canadians complain that they get many pointless
| alerts that can't be disabled.
| [deleted]
| Teknoman117 wrote:
| I didn't really feel it in San Mateo, but the blinds were
| swinging in the office so it was definitely moving some stuff up
| here.
| vincentriemer wrote:
| Weird, I'm in Foster City and felt the strongest shaking I've
| ever felt in my time in the Bay Area.
| Kina wrote:
| Foster City will amplify any shaking since the entire city
| was built on compacted fill and reclaimed earth.
| delabay wrote:
| didn't feel in san mateo either
| samstave wrote:
| Loma Prieta in ~1989 was NUTS.
|
| I lived in lake tahoe at the time and was a freshman in HS and
| was at football practivce at 5:04 PM when it happened, and my dad
| was waiting in the car and it car shook so much he got out
| because he thought us kids were pranking him by jumping on his
| bumper....
|
| This 5.1 is a good thing, as it has relieved geo-stress... (I
| hope!)
|
| but as a california native, I think of earthquakes like I do
| california poppies (which I just planted a bunch of) they are
| magnificent, just dont pick any...
|
| EDIT: The 1989 earthquake was also in october.... October 11 I
| think... but I wonder if the seasonal shift in temperatures
| affect earthquakes. As October is generally the best month in the
| bay area weather-wise...
| macintux wrote:
| I caught a much smaller one when I was young and had the exact
| same reaction your dad did, sitting in a parking lot with no
| one around. I had a better excuse than him: I was in central
| Indiana, and who ever heard of a quake there?
|
| (No, not looking forward to another New Madrid quake.)
| russellbeattie wrote:
| The stories of the New Madrid quakes are insane. The earth
| was literally rolling, fissures opened up spewing enough
| gases to block out the light and more. And the aftershocks
| went on for months. Hard to imagine.
| 0xB31B1B wrote:
| 5.x earthquakes are not "stress relievers", that is a common
| fallacy.
| kirubakaran wrote:
| https://earthquake.usgs.gov/research/eqproc/grdmotion.php
|
| Especially:
| https://histre.com/highlights/kirubakaran/5b7c1756
| mturmon wrote:
| You seem to be writing to correct the commenter above, but
| in fact the commenter is correct. Because the M scale is
| logarithmic, you need a _lot_ of M5 's to release energy
| equivalent to an M6. So, the M5's aren't helping to
| suppress the M6's. A few seconds of searching will turn up
| authoritative sources on this oft-heard misconception.
| outworlder wrote:
| > but I wonder if the seasonal shift in temperatures affect
| earthquakes.
|
| This one was 4 miles deep. That would be surprising.
| mc32 wrote:
| You'd need like a hundred 5.1s to "relieve the geo-stress".
| cowmix wrote:
| I flew to the bay area for the first time in spring of '90 for
| a business trip. I was driving in my rental car with my paper
| street map(s). I went to cross the San Francisco-Oakland Bay
| Bridge and, well, a lot of was gone because of the quake.
| ROTMetro wrote:
| Was in the Santa Cruz area at football practice in 1989. My
| knees were in my face. We were not able to go into our house
| for a week until it was determined safe. Us and all our
| neighbors camped in our front yards and had a huge block party.
| The community was left to fend for ourselves with no water and
| no power but everyone coming together. Grocery stores opening
| with no power letting in like 20 people at a time. It was
| probably the most a part of a community I ever felt in
| California. Hiking Nisene to see the epicenter was cool. Me and
| some other football players went around looking for people that
| could use overexcited football linemen teenager help. We moved
| so many trees/branches, and were feed so much BBQ steak (no
| power so everything in fridges was getting grilled up and
| shared).
| hirundo wrote:
| I was in an office tower in Santa Clara, about half way up, on
| the sixth floor. The building swayed so much I thought it would
| pitch over and kill me. But the valley had gotten off easy
| compared to the Santa Cruz Mountains. My brother's home looked
| like a giant toddler and played with it for half an hour before
| putting it down again. If we had gotten that kind of treatment
| in Santa Clara I wouldn't be able to write about it.
|
| That earthquake shook me deeply. It's not a coincidence that I
| now live on a whole different tectonic plate.
| beefman wrote:
| Handy calculator to convert between magnitude and energy:
|
| https://earthalabama.com/energy.html
| alanwreath wrote:
| I came here only to question why this news even registers on HN
| news.
| karaterobot wrote:
| HN works on a voting system, so that people can register what
| they feel is important, and if enough people do that then
| things show up on the front page.
|
| There's a bit more information available here:
| https://news.ycombinator.com/newsfaq.html
| throw8383833jj wrote:
| it's interesting to compare and contrast your experience with
| someone else's. And since this is an experience everyone around
| here has had, we have it all in common, unlike say if there's a
| robbery on 1st street which might affect less than .0000001% of
| users on this site.
| AnimalMuppet wrote:
| Because it interests us.
| sophacles wrote:
| Are you asking: "why does the site with 'news' in it's name
| report news?"
|
| Or are you asking: "how does this earthquake in the place where
| much tech is centered and a large number of HN users live
| pertain to HN?"
|
| The answer turns out to be the same: it's relevant to a lot of
| people here and they upvoted it.
| alanwreath wrote:
| These are all obvious answers. Still begs the question of
| what's the value of having these discussions _here_. There
| are plenty of discussions that are not permitted on HN (even
| if they would garner useful discussion). I only posit that
| this type of news also lends no value to this forum (SV
| locals don 't or shouldn't depend on HN for local emergency
| news), and so should be removed/banned. Just my 2C/ -
| downvote away.
| sophacles wrote:
| I find it helps to remember that I don't have to click on
| every link on this site. If something doesn't look
| particularly appealing to me, I remind myself that there
| are other folks who read the site too, and while I don't
| understand why some of the things here are interesting to
| folks it's still OK that they are here - I am not the sole
| member of the "target audience". I just skip that link and
| read something more appealing.
| temp_praneshp wrote:
| It enabled this comment:
| https://news.ycombinator.com/item?id=33335391 which, I
| would argue, adds a lot of value.
| s1artibartfast wrote:
| There is fascinating science and technology associated with
| earthquakes, as well as interesting stories and history
| (though fewer of those in this thread)
| fragmede wrote:
| the value is connection. you're free to disregard that, but
| as humans, and not automatons, we sell to connect to out
| fellow humans in more ways than work. now, you can point
| out that it's a very SV-centric post, and it is, but
| there's a ton of other SV news here, so that objection's
| probably moot. Other regions of the world experience
| earthquakes and the discussion of the science and
| technology behind the early warning system that was
| deployed is interesting beyond the bay area.
| iancmceachern wrote:
| Because many of us live in the area and therefore are deeply
| impacted by things like this.
| tick_tock_tick wrote:
| Cause most of us live here.....
|
| Or at-least depend on companies located here.
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