6 ms·

Link to the actual buoy data page: http://www.ndbc.noaa.gov/station_page.php?station=46410&type=2&seriestime=20180123093315 http://www.ndbc.noaa.gov/station_pag

Link to the actual buoy data page: http://www.ndbc.noaa.gov/station_page.php?station=46410&type=2&seriestime=20180123093315 http://www.ndbc.noaa.gov/station_page.php?station=46410&type... Worth noting that other nearby buoys don't show such a dramatic wave: http://www.ndbc.noaa.gov/station_page.php?station=46409&type=2&seriestime=20180123093200 http://www.ndbc.noaa.gov/station_page.php?station=46409&type... Here's a map: http://www.ndbc.noaa.gov/obs.shtml http://www.ndbc.noaa.gov/obs.shtml (click on the blinking ones) And here's a map of tsunami-capable tide stations: https://tidesandcurrents.noaa.gov/tsunami/# https://tidesandcurrents.noaa.gov/tsunami/#

dawnerd 9y ago
Thanks, was having trouble getting it to load on my phone.
wiredfool 9y ago
I'd be _really_ suspicious of data showing a 10M tsunami in the open ocean. In deep water, they're super long wavelength low amplitude waves, it's only when they interact with the bottom that the wave piles up and gets to large amplitude.
- z3t4 9y ago
  yeh, that would be like over 100m when it hits shallow water. But if the water level is unusually low then GTFO!
onnoonno 9y ago
What I don't get is that nearly all the buoys that have that moving icon "Tsunami alert" show some excitation at the ~9:45GMT mark. But I would of course expect the buoys that are farther away to only show some kind of peak when the wave actually reaches them. And it looks like they are thousands of km away, so some of them should not even have been reached yet. Some what is going on there? Is the data time actually shifted and not in GMT but 'earthquake propagation time'? Am I reading the plots wrong?
- adanto6840 9y ago
  I'm probably completely wrong, but am wondering and trying to deduce the same thing. My assumption, guess really, is that they were remotely activated into "Tsunami Mode" -- a more rapid-pulse reporting mode or similar, which just is a bit noisier perhaps? Total layman's guess though -- would love to know more if anyone knows the answer.
  - onnoonno 9y ago
    > My assumption, guess really, is that they were remotely activated into "Tsunami Mode" -- a more rapid-pulse reporting mode or similar, which just is a bit noisier perhaps? That sounds like a very good guess. But then, the spikes that are purported to be the Tsunami in the media is just the ADC having a couple bad samples from being switched into a different mode or so :-) If any USGS person is reading this thread here: Take it as a issue report that your page should be readable and understandable by lay persons, at least lay persons with a non-geophysics STEM background :D
  - deleted 9y ago
    [deleted]
- JorgeGT 9y ago
  Not an oceanic scientist but sound speed in water is ~1500m/s. This is the speed at which a pressure perturbation propagates. The speed at which the actual tsunami wave would propagate is much more slower than this. So I believe that the excitation marked in the plot is the pressure wave caused by the earthquake, which travels orders of magnitude faster than an actual water wave caused by the earth displacement.
  - onnoonno 9y ago
    But that doesn't fit the data, either. The buoys all report something around the 9:45ish GMT mark. And 1500m/s would mean you reach Mendocino bay in California only about now or so. But have a look at the plot: https://archive.fo/KsN8b https://archive.fo/KsN8b
willvarfar 9y ago
At the top of those pages I see this message: > Due to the Federal Government shutdown, NOAA.gov and most associated websites are unavailable. This site will remain accessible during the federal government shutdown; however, information on the site may not be up to date and we may not be able to respond to inquiries until appropriations are enacted so, is it up to date?
- onnoonno 9y ago
  At least the time stamps in the plots seem to correspond to current time in GMT.

dawnerd 9y ago

Thanks, was having trouble getting it to load on my phone.

wiredfool 9y ago

I'd be _really_ suspicious of data showing a 10M tsunami in the open ocean. In deep water, they're super long wavelength low amplitude waves, it's only when they interact with the bottom that the wave piles up and gets to large amplitude.

z3t4 9y ago
yeh, that would be like over 100m when it hits shallow water. But if the water level is unusually low then GTFO!

onnoonno 9y ago

What I don't get is that nearly all the buoys that have that moving icon "Tsunami alert" show some excitation at the ~9:45GMT mark. But I would of course expect the buoys that are farther away to only show some kind of peak when the wave actually reaches them. And it looks like they are thousands of km away, so some of them should not even have been reached yet. Some what is going on there? Is the data time actually shifted and not in GMT but 'earthquake propagation time'? Am I reading the plots wrong?

adanto6840 9y ago
I'm probably completely wrong, but am wondering and trying to deduce the same thing. My assumption, guess really, is that they were remotely activated into "Tsunami Mode" -- a more rapid-pulse reporting mode or similar, which just is a bit noisier perhaps? Total layman's guess though -- would love to know more if anyone knows the answer.
- onnoonno 9y ago
  > My assumption, guess really, is that they were remotely activated into "Tsunami Mode" -- a more rapid-pulse reporting mode or similar, which just is a bit noisier perhaps? That sounds like a very good guess. But then, the spikes that are purported to be the Tsunami in the media is just the ADC having a couple bad samples from being switched into a different mode or so :-) If any USGS person is reading this thread here: Take it as a issue report that your page should be readable and understandable by lay persons, at least lay persons with a non-geophysics STEM background :D
- deleted 9y ago
  [deleted]
JorgeGT 9y ago
Not an oceanic scientist but sound speed in water is ~1500m/s. This is the speed at which a pressure perturbation propagates. The speed at which the actual tsunami wave would propagate is much more slower than this. So I believe that the excitation marked in the plot is the pressure wave caused by the earthquake, which travels orders of magnitude faster than an actual water wave caused by the earth displacement.
- onnoonno 9y ago
  But that doesn't fit the data, either. The buoys all report something around the 9:45ish GMT mark. And 1500m/s would mean you reach Mendocino bay in California only about now or so. But have a look at the plot: https://archive.fo/KsN8b https://archive.fo/KsN8b

willvarfar 9y ago

At the top of those pages I see this message: > Due to the Federal Government shutdown, NOAA.gov and most associated websites are unavailable. This site will remain accessible during the federal government shutdown; however, information on the site may not be up to date and we may not be able to respond to inquiries until appropriations are enacted so, is it up to date?

onnoonno 9y ago
At least the time stamps in the plots seem to correspond to current time in GMT.