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Tsunami warning ends for B.C. after large earthquake strikes off Alaska

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Re: Tsunami warning ends for B.C. after large earthquake strikes off Alaska

#91
post #16
post #10

The tsunami alert: http://ptwc.weather.gov/ptwc/text.php?id=hawaii.TSUHWX.2018.... IF TSUNAMI WAVES IMPACT HAWAII THE ESTIMATED EARLIEST ARRIVAL OF THE FIRST TSUNAMI WAVE IS 0423 AM HST TUE 23 JAN 2018

Do you know why these reports mention Hawaii, rather than (say) Vancouver and other coastal cities nearer to the epicenter, where I would imagine a tsunami would reach first?

Victoria is a better target city. Vancouver is sheltered by Vancouver Island where Victoria is considerably more exposed.

Re: Tsunami warning ends for B.C. after large earthquake strikes off Alaska

#92

https://twitter.com/SF_emergency/status/955764708442714113 San Francisco Department of Emergency Management has tweeted that people within three blocks of the coast or five blocks of the San Francisco Bay should be prepared to evacuate. Tsunami Watch for #SF. If you are w/in SF & 3 blocks of the Pacific Coast or w/in 5 blocks of SF Bay, PREPARE TO EVACUATE SO YOU ARE READY IF EVACUATION IS NEEDED. Check on neighbors…

I'm a recent newcomer to the Bay area. What is the Tsunami situation for places like Mountain View? Places like the GooglePlex are pretty close to the Bay. Is there even any real high ground in the area?? If something happens for real, do sirens sound?

Excluding the coast and the east bay, it is not really a concern. A tsunami would have to come through the golden gate channel and make a quick turn to get to Mountain View with any strength.

The inundation map for Mountain view is here: http://www.conservation.ca.gov/cgs/geologic_hazards/Tsunami/...

And here is one for the entire bay area: http://www.conservation.ca.gov/cgs/geologic_hazards/Tsunami/...

The remainder of the inundation maps can be found here: http://www.conservation.ca.gov/cgs/geologic_hazards/Tsunami/....

Here is an animated simulation of a tsunami hitting the bay area: https://www.youtube.com/watch?v=bP_AIWgknfI

Re: Tsunami warning ends for B.C. after large earthquake strikes off Alaska

#93
post #79

Earlier quoted context omitted.

How would they know cell phone numbers? Where I live they call landlines for emergency alerts but there's no other way to specifically target residents.

How do amber alerts work? When I lived in SF I got SF-related alerts. I don't know enough about how they work - but it sounds like tech that could be re-used for major emergency alerts.

As I should have realized, they're sent to all wireless phones in the area. On an iPhone at least both Amber and Emergency alerts are on by default but you can turn either of them off.

Re: Tsunami warning ends for B.C. after large earthquake strikes off Alaska

#95

Earlier quoted context omitted.

You can also quickly access this info at http://www.tsunami.gov . Or at least normally it's quick; page is taking a good 10 seconds to load for me right now—under a bit of load, presumably. It includes Canada as well. (In fact, the BC Emergency site quotes from it and links back to it!)

The servers/pipes at tsunami.gov are clearly grossly underpowered for their intended use. Hopefully, they'll be able to get some equipment upgrades as a result of this.

I wonder what their infrastructure looks like. This is the poster case for a scalable cloud setup. 99%+ of the time their traffic is probably nearly zero, and when there will be a significant spike it's generally going to be predictable!

Re: Tsunami warning ends for B.C. after large earthquake strikes off Alaska

#96
post #34

Earlier quoted context omitted.

Faster than an airplane though.

Perhaps, the arc distance traveled for the wave is a smaller than the plane's. The plane is flying 10Km in the sky.

The difference in arc lengths is less than you'd think--

It's only about 20km further assuming Alaska is 1/3 of the world's circumference away from Australia.

  (1/3)*(2*pi*(r+10) - 2*pi*r) = (1/3)(20*pi) ~= 20

Re: Tsunami warning ends for B.C. after large earthquake strikes off Alaska

#97
That's a big quake! Thank God didn't cause a tsunami, although data from buoys showed VERY early on that probability was VERY low for such an occurrence. Watch for sustained wave height for serious tsunami warnings, issues coming onshore. Should you see a quick rise, sustained or increasing height offshore, then a drop... Don't wait for it! Get off the beach, away from waterways & to higher ground. I suppode those of us in California need to be on watch for the next few weeks! DutchSinse on YouTube has been working on earthquake prediction for years, and although not 100% accurate, he's been a LOT more accurate than anyone else, and has nailed the bigger quakes. I haven't taken the time to learn his methods insideout, but I've seen him call accurately numerous earthquakes. I believe with more funding, and a staff, this guy could save many, many more lives. Having worked with these buoys, and on other NOAA projects, this DutchSince guy has a method to call earthquakes early. PLEASE support him! He is the best bet to predict quakes, to tell the difference between quakes and drilling, quakes set off by drilling, etc. He's self-taught, and is more of a scientist than many I've met that went through years of "training" of methods that simply don't work. He breathes & lives this stuff, and he is onto something, far more than ANYONE else! He gets resistance from oil companies, which is sad, as he can save them money and lives! So get your batteries, your earthquake kits, Ham radios & be ready! Stay safe, always be prepared & ready for any type of disaster! Stay safe!

Re: Tsunami warning ends for B.C. after large earthquake strikes off Alaska

#98
post #96

Earlier quoted context omitted.

Perhaps, the arc distance traveled for the wave is a smaller than the plane's. The plane is flying 10Km in the sky.

The difference in arc lengths is less than you'd think-- It's only about 20km further assuming Alaska is 1/3 of the world's circumference away from Australia. (1/3)*(2*pi*(r+10) - 2*pi*r) = (1/3)(20*pi) ~= 20

Wow, that is surprising. I should have thought about it further. The radius of earth is 6371Km and 10Km works out to be 0.15% of it. So 20Km is reasonable.
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