The USGS's automated systems calculate the location and focal mechanism/moment tensor pretty much instantly from the seismic network. The system should know that a significant tsunami is unlikely based on the parameters of the earthquake. On the one hand, it's good to be cautious, but on the other hand, a system designed to cry wolf is also self-undermining. Maybe they should have a tiered warning system?
There are many steep canyons on the Pacific coast, and here is just one example of mass casualties from a tsunami resulting from a submarine landslide triggered by a strike-slip fault earthquake:
Caltech, 2018[1]: "Contrary to Previous Belief, Strike-Slip Faults Can Generate Large Tsunamis"
[1] https://www.caltech.edu/about/news/contrary-to-previous-beli...
The reason that the Palu event is so notable is precisely because it's uncommon. It's also a very different system: the causative fault is running along the axis of a shallow bay that is only a few km across, so even if the landslide did occur, rapid movement of the steep, shallow coastlines would surely have generated a smaller tsunami. It's a geographical and tectonic situation in which at least a minor tsunami is expected a priori conditional upon an earthquake, so a warning system would account for that in principle. (In practice there isn't time enough to mobilize because the tsunami hits while the ground is still shaking). The bay at Palu is like a somewhat larger Tomales bay--an earthquake right there is going to make some waves. Very different situation than one far off shore.
There is a tiered system, its calibrated based on a combination of magnitude and warning time for the initial alerts (updated notices are based on other measurements and observations, but if gathering and analyzing observations before an initial warning doesn't leave time to act on it, it doesn't matter how accurate the warning is.)
Here is an example of the first message sent 9 minutes after 2011 Tōhoku earthquake https://imgur.com/a/1mwAKqc.
According to a USGS guy on the news just now, this isn't true. They know the location, and the magnitude, but the moment tensor takes time. Therefore any ocean earthquake 7.0 or above triggers an immediate tsunami warning.
It's a complication that will never happen, but sometimes I think it would be cool if HN had a way of authenticating experts and giving them flair. So many legit smart people here.
https://www.tsunami.gov/events/PAAQ/2024/12/05/so1aq0/1/WEAK...
(Some of my job requires me to deal with natural disaster public warnings; but not tsunami specifically)
(I'm late to the party. The warning has since been cancelled: https://www.nbcbayarea.com/news/california-earthquakes-tsuna...)
And then there’s this tsunami alert today.
There was a ton of flooding on flat roads and highways during the last week+ long storm session. I saw several lanes impassable on 101, and several spots in SF where a car could easily have gotten flooded.
All the alerts I got were basically "please don't drive" and not "you're gonna die!", which I think is totally reasonable.
I've gotten the warning and my street is perfectly fine... and then I look at social media and cars on the street are half-submerged just 20 blocks away.
You might not even be aware of elevation differences when they're gradual.
I guess people can go on twitter and read some random posts.
Of course, when I tap on the notification and open the app, I see that it's actually driven by an air quality alert because the AQI will be 112 (which isn't even that high.)
Come on guys - the dictionary defines weather as, "the state of the atmosphere with respect to heat or cold, wetness or dryness, calm or storm, clearness or cloudiness."
This was confusing because the warning was called off earlier for a different region while still in effect for this one (https://news.ycombinator.com/item?id=42331931).
Edit: arrival time has come and gone. No indication of movement in water level.
This is quite relaxing, I agree. Here's a couple from Pacifica, CA for you.
On that note, I checked feeds at both Ocean Beach and Linda Mar at the predicted time but didn't see anything unusual, except that they apparently made all the surfers get out (first time I've ever seen Linda Mar empty of surfers during daylight hours apart from big storms/flat spells). OB had a bunch of spectators lined up on the dunes... an interesting reaction to a tsunami warning is "let's go to the beach and watch!".
* Boat operators,
* Where time and conditions permit, move your boat out to
sea to a depth of at least 180 feet.
* If at sea avoid entering shallow water, harbors,
marinas, bays, and inlets to avoid floating and
submerged debris and strong currents.What I was surprised by is how behind the iPhone was. I expected iPhone to be on par with android in terms of safety alerts.
Anybody know if there is a way to get the early alerts on iPhone like I did on the android phone?
In general my impression of Android is that it’s quite ‘leaky’ and apps can abuse it quite easily and iPhone is more secure. Would love to hear thoughts on this or point me to resources that address this question.
Generally an earthquake warnings are issued by someone always automatically correlating sensors everywhere, USGS and/or NOAA in case with US, and then cellular carriers broadcasting the alert through LTE feature. This does not work without participating local equivalent of USGS deploying a sensor network and running its computers wired to carriers.
This feature is carrier agnostic, enabled by default, and mandatory on phones; it's specifically designed to deliver earthquake early warnings. It does not matter if it's Android, iOS, or something else altogether. Any phones, SIM locked or unlocked, with or without SIM, should start blaring the alert so long it hears the signal.
On iOS you have no such thing and you either rely on the carrier alert (there won't always be one) or install an earthquake alert app such as MyShake.
PWS is also a broadcast, meaning the phones don't have to wait for cellular timeslots, so it's faster and bandwidth efficient in that regard too.
The Android Alerts are actually coming off of IPAWS as well, but I believe they take a feed directly from the publishing system and do all of the routing themselves. Their implementation is of course quite a bit faster than IPAWS rather creaky and sort of batch-centric architecture.
Reality doesn't care what you think should be the fastest.
[Edit:] All too real scenario: Carrier knows about particular IP addresses and ports used by alert service. Carrier makes provision for separate path for it. Carrier also tries to shave said provisioning to the bone, calculates a worst-case, and adds 5% capacity. Which doesn't get updated when that particular app gets a 6% boost in subscriptions. Back in the old days the traffic management folks would be on top if it, but that's all been outsourced...
(Source, worked at Google in Android team.)
You can do a location-based two way warning system and there are such services, but it's going to be laggy and won't scale to 100M+ simultaneous subscribers. One-way broadcast scales to the planet if wanted.
Androids also give tsunami warnings, when appropriate. There was 1 issued just a few weeks ago after an off-shore earthquake in SoCal.
tldl: I do think the recommendation was installing the official ShakeAlert app
[0] https://podcasts.apple.com/mu/podcast/two-possible-futures-f...
* Notification path. IoS at the time was pretty protective of the user's battery, and had specific services you had to use. I imagine there's special treatment now for emergency communications.
* Phone state. How deeply asleep is it? Are there other background apps frequently contacting the mothership? Multiple apps can get their requests batched together, so as to minimize phone wake-ups. You can also benefit from greedy apps--VoIP apps, for example, might be allowed/figured out a hack to allow frequent check-ins, and the other apps might see a latency benefit.
* Garbage carriers. Hopefully emergency alerts have a separate path, but I've noticed my provider (who shall remain nameless but is a three-letter acronym with an ampersand in the middle) sometimes delays SMS messages by tens of minutes. (TBF, in my case there might also be a phone problem [Android], but since nameless provider forced it on me when they went 4G-only they're still getting the blame.)
In your case, my money would be on the carrier. Pushing a notification to all phones in an area can be taxing, and cheaping out on infrastructure is very much a thing.
For docs, your best bet would be to go to the developer sites and pull up the "thou shalt..." rules, particularly regarding network activity, push notification, and permitted background activities. And yeah, Apple was much more dictatorial, for good reasons.
wasn't the official name switched to no longer use that ampersand so it is just the three letters now (and for some time)?
Or maybe ampersand was dropped before SBC bought the remaining parts of the old business and reformed T-1000 with the ampersand?
I really wish we had something like NERV but for SF, NERV works so well whenever I'm in Japan. It will literally show you a countdown of exactly when you'll feel it and it's very accurate, and you can see a livemap of monitoring stations reporting it in real time as the wave makes its way towards you.
I've lost 15 minutes already because of your comment, and am on track to lose CARROT only knows how much more.
Not only did you prompt me to download CARROT weather, I was foolish enough to set it on the "overkill" personality setting. I was amused by the banter until I found the "achievements" section. Then I saw that there was an achievement for downloading the Vision Pro app, so of course I had to get that one.
I thought it was going to be difficult resisting enslaving myself to the will of CARROT on my iPad... woo boy. I wasn't prepared for the Neal Stephenson-flavored counterfeit GLaDOS that awaited me in visionOS.
A bunch of people got off, and then the conductor comes back on the PA system to say the speed limitation had been limited and "we'll be going back to 79 MPH, hold on to your hats"
The easily found page about Caltrain's response to earthquakes [1] doesn't include magnitude 7, but also doesn't include earthquakes more than 100 miles from the tracks either. So I think a brief reduction in speed is reasonable for a large quake within the larger area and quickly ending the restriction as its confirmed the quake was outside the policy scope.
[1] https://www.caltrain.com/rider-information/safety-security/e...
TSUNAMI THREAT FORECAST...UPDATED ---------------------------------
* THERE IS NO LONGER A TSUNAMI THREAT FROM THIS EARTHQUAKE.Edit:
Now as of "1154 AM PST Thu Dec 5 2024" the warning is canceled:
https://www.tsunami.gov/events/PAAQ/2024/12/05/so1aq0/3/WEAK...
It looks like https://tsunami.gov/?p=PHEB/2024/12/05/24340001/2/WEPA40 is the 11:29 PST message saying there is no tsunami warning for "Non-US/Canada Pacific".
And it looks like https://tsunami.gov/?p=PAAQ/2024/12/05/so1aq0/2/WEAK51 is the 11:25 PST message saying there is still a tsunami warning for "AK/BC/US West Coast".
But it's not easy to tell what one's looking at if one doesn't already understand the system, and conditions of "extreme danger" (which is what my phone told me about half an hour ago) are not a good moment to figure these out.
Edit: here we go: https://tsunami.gov/?p=PAAQ/2024/12/05/so1aq0/3/WEAK51 now says "No Tsunami Warning, Advisory, Watch, or Threat" for "AK/BC/US West Coast" as of 11:55 PST.
FORECASTS OF TSUNAMI ACTIVITY
-----------------------------
* Tsunami activity is forecasted to start at the following
locations at the specified times.
FORECAST
START
SITE OF TSUNAMI
---- ----------
* California
Fort Bragg 1110 PST Dec 5
Crescent City 1120 PST Dec 5
San Francisco 1210 PST Dec 5
* Oregon
Port Orford 1120 PST Dec 5
Brookings 1125 PST Dec 5
Charleston 1140 PST Dec 5
https://www.tsunami.gov/events/PAAQ/2024/12/05/so1aq0/2/WEAK...
which (still) says:
* No tsunami observations are available to report.
And another one at: https://www.tsunami.gov/events/PHEB/2024/12/05/24340001/2/WE...
intended for a worldwide audience which says:
* THERE IS NO LONGER A TSUNAMI THREAT FROM THIS EARTHQUAKE.The earthquake was real but it is probably really hard to predict if that leads to a tsunami.
Crescent city has a long history of being devastated by norcal quakes due the the bathymetry and costline profile.
https://www.youtube.com/live/ESsx4MdloQw?si=PQSwV06GsYfwOZPj
For a Midwesterner a Tornado Warning requires someone to see it, or be be detected by radar. It's usually a good indicator that it is highly likely that the tornado exists and it is actively doing its thing somewhere. Warnings are pretty specific and almost always involve the thing happening.
Tsunami though, would it have to exist as far as seeing it on the coast, or is this more of a "conditions are ripe" kind of event?
I wonder if the Tsunami situation with all the under water variables is a lot more unknown?
A warning, the highest level, means “a tsunami with the potential to generate widespread inundation is imminent, expected, or occurring.”
The actual criteria are here:
https://tsunami.gov/operations/opsmanual.pdf (Section 3)
Note that the level of initial alert for an area is influenced by both the magnitude of the quake and the distance/time from quake to the area the alert covers.
> I wonder if the Tsunami situation with all the under water variables is a lot more unknown?
Yeah,I don't think there is anything as clear and with the coverage of radar for tsunamis, and warning when you see one is going to be too late.
But at sea there’s not much to obscure satellite signals so I believe resolving buoy position was a solved problem back when gps car navigation still sucked balls because tall buildings make everything harder. You need a lot more satellites to see three or four at the same moment.
here is an interactive map, looks like some of them are picking up something https://www.ndbc.noaa.gov/obs.shtml?lat=13&lon=-173&zoom=2&p...
https://earthquake.usgs.gov/earthquakes/eventpage/us7000nw7b...
(early estimates of magnitude tend to vary; looks like magnitude estimates are currently ranging from 6.0 to 7.3)
* The following parameters are based on a rapid preliminary assessment of the earthquake and changes may occur.
* Magnitude 7.3 * Origin Time 0944 AKST Dec 05 2024 1044 PST Dec 05 2024 1844 UTC Dec 05 2024 * Coordinates 40.3 North 124.7 West * Depth 8 miles * Location 45 miles SW of Eureka, California 215 miles NW of San Francisco, California
1) The blanket warning for areas that are clearly outside inundation zones drives a lot of confusion/fear. We can vastly improve our warning infra by utilizing better geo data to drive more effective alerts. For example, Tsunami inundation zone data is well known. Why not send only to phones currently in and maybe within 250m of those zones?
2) A lot of 'am I in a tsunami inundation zone?' sites were broken when I checked. them. Official government sites too. Of course that could be a function of traffic, but if so, it demonstrates a lack of resilience in their systems. We need better.
There's often significant lag between the earthquake and the arrival time. You don't just want the people in the inundation zone to know, you also want everyone else to know to stay away.
That's not just a theoretical edge case. If this had been a major tsunami your system would have killed me just now. I would have been outside of your suggested range and alone at the time of the alert, but was planning to walk my dog along the water front at noon, which was just around the projected arrival time.
> * The Tsunami Warning is canceled for the coastal areas of California and Oregon
BULLETIN
Public Tsunami Message Number 3
NWS National Tsunami Warning Center Palmer AK
1154 AM PST Thu Dec 5 2024
...THE TSUNAMI WARNING IS CANCELLED...
* The Tsunami Warning is canceled for the coastal areas of
California and OregonFort Bragg California 1110 AM.PST. December 5.
Crescent City California 1120 AM.PST. December 5.
Port Orford Oregon 1120 AM.PST. December 5.
Brookings Oregon 1125 AM.PST. December 5.
Charleston Oregon 1140 AM.PST. December 5.
San Francisco California 1210 PM.PST. December 5.
Edit. Noticed it says in small print lower down the page: "Note: Times are local to your browser, unless otherwise indicated" so either I missed that before, or someone on this thread fixed it...
https://www.iplivecams.com/live-cams/crescent-city-harbor-di...
It seems very odd how some quite low lying shore areas in the SF Bay are excluded while other areas are painted over very high elevations including the SF peninsula and Oakland/Berkeley hills.
Fort Bragg California 1110 AM.PST. December 5.
Crescent City California 1120 AM.PST. December 5.
Port Orford Oregon 1120 AM.PST. December 5.
Brookings Oregon 1125 AM.PST. December 5.
Charleston Oregon 1140 AM.PST. December 5.
San Francisco California 1210 PM.PST. December 5.
The tsunami warning will remain in effect until further notice. Refer to the internet site tsunami.gov for more information.
- 7.2 on 2010-04-04
- 7.3 on 1992-06-28
https://en.wikipedia.org/wiki/List_of_earthquakes_in_Califor...
They also released a warning before the 2009 tsunami in American Samoa but I'm not sure how effective it was due to the short timeframe and speed of disseminating the info