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After 7.0 Earthquake, Coastal Northern California Phones Get 'Tsunami Warning' Alert (Since Cancelled) (sfgate.com) 46

A tsunami warning was issued — and then cancelled about an hour later — for 400 miles of California coastline after a 7.0-magnitude earthquake struck off the coast near California's northern border with Oregon. "About 5 million people were under the warning while it was in effect," reports a San Francisco news site.

Phones had sounded with an emergency tone in affected areas, with a warning that "You are in danger. Get away from coastal waters. Move to high ground or inland now." Warning sirens sounded in some areas, and as a precaution San Francisco paused service for its BART trains travelling under the San Francisco Bay. But while tsunami waves were originally predicted to hit San Francisco at 12:10 p.m. — they didn't. New information prompted the cancellation of the tsunami warning.

Thanks to long-time Slashdot reader sinij for sharing the news.

After 7.0 Earthquake, Coastal Northern California Phones Get 'Tsunami Warning' Alert (Since Cancelled)

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  • Vertical shaking (Score:5, Interesting)

    by hadleyburg ( 823868 ) on Thursday December 05, 2024 @04:30PM (#64994089)

    Fortunately this quake, although shallow, seems to have not done much damage.

    One thing that is pretty disconcerting about earthquakes is vertical shaking. Horizontal movement is somehow more acceptable - lights swinging, doors and windows rattling. But a sudden drop that feels like turbulence during a flight is quite a shock. That faith that you have always had, that the earth under your feet will essentially remain where it is, is questioned.

    • by skam240 ( 789197 )

      Yeah, fortunately there isnt a lot of stuff up that way in California. It's pretty lightly populated.

    • by bjoast ( 1310293 )

      That faith that you have always had, that the earth under your feet will essentially remain where it is, is questioned.

      Thank you for that vivid description. I hope I never have to experience that.

      • I have been through 3 Los Angeles area quakes. It is not a good experience. I recall a journal paper or letter from the 1992 Cape Mendocino quake, describing an acceleration estimate derived by measuring the distance between before and after imprints in dirt of the tracks of a bulldozer at a construction site, that hopped from the quake. The shaking was violent enough to saturate the instrumentation in the area.

        I felt that one at a considerable distance away. I was sitting in a car at the drive-through

    • The damage inflicted by shaking depends on the design of the structure vs. the type of shaking. Not clear you can make a blanket statement.

  • by Valgrus Thunderaxe ( 8769977 ) on Thursday December 05, 2024 @04:46PM (#64994133)
    I'd rather this infrequent and minor inconvenience than no warning at all.
    • Re: (Score:2, Interesting)

      by dgatwood ( 11270 )

      I'd rather this infrequent and minor inconvenience than no warning at all.

      Except it isn't. If you're coastal, you have to stop what you're doing and go to higher ground. People end up evacuating for no reason. And if it keeps happening like this, they're going to start ignoring the warnings, and then when there's an actual tsunami (assuming that's actually possible given the shape of the sea floor, which may or may not be the case), a whole lot of people are going to die.

      We need actual real-time swell monitoring, not "Ooh, there was an earthquake, so there might be a tsunami".

      • Are they training us?

      • Yes, false warnings are a problem. But the alternative may be to wait until you are certain and by that time it is too late for some people to reach safety. A difference of just a few minutes may be the difference between life and death. I am not sure there is a wave detection system that fixes that. Fleeing unnecessarily is just life in a tsunami zone. You don't have to but that choice may eventually kill you.
        • by dgatwood ( 11270 )

          Yes, false warnings are a problem. But the alternative may be to wait until you are certain and by that time it is too late for some people to reach safety.

          We got the tsunami warning at a few minutes before 11, not long after the earthquake, with a predicted wave arrival time of 12:10. It took almost an hour before they concluded that there wouldn't be a tsunami, which meant many people would *just* finished packing up and started heading to higher ground when they cancelled it. That's about as bad as you can get timing-wise.

          What we need is a very large mesh of GPS-equipped (and possibly sonar-equipped) buoys with ten-mile spacing, extending a hundred miles

          • That's about as bad as you can get timing-wise.

            Only because there wasn't one. If there had been a Tsunami and it had hit at 11:50 instead of 12:10 THAT would be bad timing. Particularly if the warning wasn't given until 11:30.

            Doing this right is mostly just a matter of throwing a little bit more money at the problem to make the hardware more weather-resistant and drive down the cost of production through economies of scale. And we really need to spend that money, because doing this badly, like what's happening now, could cost lives.

            I think it would be interesting to determine how many people didn't get the warning message at all. We were just north of the warning area and got the warning on our phones. But there was still traffic headed south into the Tsunami zone.

            Finding arrival times or even the exact boundary of the warning were not all that straight for

            • by dgatwood ( 11270 )

              That's about as bad as you can get timing-wise.

              Only because there wasn't one. If there had been a Tsunami and it had hit at 11:50 instead of 12:10 THAT would be bad timing. Particularly if the warning wasn't given until 11:30.

              First that's not a realistic scenario. Tsunami waves travel at a well-defined speed that's proportional to the depth of the water, and that part of the ocean is thoroughly mapped. They're not going to be off in their estimate by a double-digit percentage.

              Second, the tsunami evacuation level in most places is significantly less than one mile inland, so twenty minutes is usually enough even if you're walking. It could be inadequate for disabled people who don't have cars, I guess, but presumably the small

      • by Anonymous Coward

        Except it isn't. If you're coastal, you have to stop what you're doing and go to higher ground. People end up evacuating for no reason. And if it keeps happening like this, they're going to start ignoring the warnings, and then when there's an actual tsunami (assuming that's actually possible given the shape of the sea floor, which may or may not be the case), a whole lot of people are going to die.

        So? It's a personal decision.
        Listen to the warnings, evacuate when unnecessarily. Then one day evacuate and save your life.
        Don't listen to the warnings. then one day die in a Tsunami.

        How is ignoring the warnings any different from the warnings not being given?
        If you don't like them, just don't play their game. You're free to die in a Tsunami if that's your preference.

      • I got the tsunami alert today. It deterred me from visiting the coast, specifically at a place that has a blue Tsunami Evacuation sign.

        I was in a mercifully low amplitude tsunami on Big Island Hawaii, from the 1964 Good Friday Alaska quake (recorded height at Hilo noted at 12.5 feet from one online source, I was at Kona). Family vacation, and we were mauka (inland) earlier in the day, and did not know about the warning, wondering why few people were around. I was in a hotel swimming pool protected by a lo

      • by ls671 ( 1122017 )

        I'd rather this infrequent and minor inconvenience than no warning at all.

        Except it isn't. If you're coastal, you have to stop what you're doing and go to higher ground. People end up evacuating for no reason. And if it keeps happening like this, they're going to start ignoring the warnings, and then when there's an actual tsunami (assuming that's actually possible given the shape of the sea floor, which may or may not be the case), a whole lot of people are going to die.

        We need actual real-time swell monitoring, not "Ooh, there was an earthquake, so there might be a tsunami". And a warning needs to be a f**king warning, meaning there IS a tsunami, not a watch, which means there MIGHT be a tsunami. The way this is currently being handled is just plain completely irresponsible.

        Well, hopefully they just state the facts in the warnings so you could make your own decision. I'd probably evacuate anyway after a 7.0 Earthquake...

        • by dgatwood ( 11270 )

          I'd rather this infrequent and minor inconvenience than no warning at all.

          Except it isn't. If you're coastal, you have to stop what you're doing and go to higher ground. People end up evacuating for no reason. And if it keeps happening like this, they're going to start ignoring the warnings, and then when there's an actual tsunami (assuming that's actually possible given the shape of the sea floor, which may or may not be the case), a whole lot of people are going to die.

          We need actual real-time swell monitoring, not "Ooh, there was an earthquake, so there might be a tsunami". And a warning needs to be a f**king warning, meaning there IS a tsunami, not a watch, which means there MIGHT be a tsunami. The way this is currently being handled is just plain completely irresponsible.

          Well, hopefully they just state the facts in the warnings so you could make your own decision. I'd probably evacuate anyway after a 7.0 Earthquake...

          The facts were "There has been an earthquake. There might be a tsunami." But the alert says "Tsunami *warning*". Emphasis mine. This implies that there *is* a tsunami. So no, unfortunately, they didn't just state the facts. They speculated based on the earthquake instead of getting the data. By the time they had the data and cancelled the warning, folks should have already been evacuating. They took too long to get the data. And that's my point — not that they shouldn't have issued the warnin

  • Let's all go to the beach and watch the tsunami!

  • From Redheaded Blackbelt News https://kymkemp.com/ [kymkemp.com] [UPDATE 12:24 p.m.: Damage Reports Coming In] 6.6 Magnitude Earthquake Shakes Northern California Near Rio Dell https://kymkemp.com/2024/12/05... [kymkemp.com] [UPDATE 1:48 p.m.] Aftershocks Continue Following 7.0 Earthquake Near Petrolia https://kymkemp.com/2024/12/05... [kymkemp.com]
    • I live in RD. Walked around my neighborhood checking for leaks, everywhere looked good. Talked to several construction laborers who were working on houses damaged in the last quake, none of them reported any new damage or other problems. Far West Mt. Pierce repeater is back up but not linking. AT&T cellular internet stayed up the whole time, Verizon went down for a while shortly before the power came back here.

  • Does that mean God hated the fish in that area of the Pacific?
  • ... the Big One.

    Some day, the San Andreas fault is going to rupture. And everything to the East will slide into the Atlantic Ocean.

    • by Anonymous Coward

      Personally, I'm moving from So Cal to the Bay Area the slow way. One quake at a time.

      • From what I recall from an interpretive display at Olema (1906 epicenter) or Point Reyes, rocks on the west side of the fault at Point Reyes, are similar to formations far south on the other side of the fault, at Tehachapi.
    • Is this really the expected future though?

      I though that the pacific plate was basically moving north-north-west along the coast...

      No longer subducting, not sliding back out (whatever the opposite of subduction is) either.. moving at a right angle to those

      The growing pressure should be more like a twisting of the land than anything, clockwise specifically
  • by LordHighExecutioner ( 4245243 ) on Friday December 06, 2024 @03:19AM (#64994955)
    ...xkcd quote [xkcd.com].
  • From our internal alerting system despite the fact I am 1000 miles away from the Pacific Ocean. Oops.
  • I am about 50 miles from the coast, and hundreds from the epicenter. I got the alert, and I did not feel a damn thing from the quake, although not far away some pools swished.

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