M7.5 from Sand Point Alaska caused a Radio Blackout

Discussion in 'Ham Radio Discussions' started by VE7DXW, Oct 20, 2020.

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  1. VE7DXW

    VE7DXW XML Subscriber QRZ Page

    Hi Everybody;


    Highlights: Tsunami Warning in the Pacific

    M7.5 91 km SE of Sand Point Alaska 2020-10-19 20:54 40.12 40 m transition waves, all band atten., precursor (-1 h to +1 h)



    Today there were 24 significant earth quakes that were recorded by the USGS ranging in the size from M4.5 to M7.5.


    All of these quakes were recorded by the RF-Seismograph. For details and a graphical capture of the propagation and explanation see graph below.


    Synopsis: The 20 m band was open at the change of the day and the 40 m band was displaying transition wave indicating that a quake was developing somewhere. The 80 m band came up after 13:00 UTC just as the 20 m was slowly fading away, with the event of some local minor quakes. The 40 m band was also open from 01:00 UTC to 02:45 UTC as the precursor of the M4.5 from Honduras struck at 03:24 UTC. Interesting are the two noise domes, before and after the quake and the slight noise increase on 15 m and 10 m. 80 m faded after 04:00 UTC as there was a lull in quakes. 80 m and 40 m came back after 06:00 UTC and then the M4.6 from Mexico releases, peaks with the quake and then slowly fades again. As the three quakes from Indonesia, a M5.6, a M5.5 and a M4.8 stuck at 07:31 UTC followed after 16 min and then 27 min later attenuated the 80 m band, but enhanced the 40 m band from 09:00 UTC past 11:00 UTC. The next set of for quakes, three of them in the Indonesia and one in Dominican Republic. The first two quakes amplified the 80 m band and then the last two attenuated but opened 40 m. There were two more M5.1 from Indonesia at 09:38 UTC followed by the second one 4 min later and the 40 m opening was extended to past 12:00 UTC. There was a quake south of Africa, a M4.9 striking at 12:20 UTC it attenuated 80 m and created a negative noise dome on 15 m. There were three more quakes after 13:15 UTC before the M7.5 but the precursor of the M7.5 can be seen effecting the 80 m band after 14:00 UTC and the 40 m band is up and down with transition oscillations starting 30 min earlier. Interesting is the fact that the 20 m propagation slowly improves after 16:00 UTC, as we get closer to the quake. The 15 m and the 20 m band go sporadic after 20:00 UTC. At 20:54 UTC the M7.5 from Sand Point Alaska releases and immediately there are 10 major aftershocks, shortly after the USGS issued a Tsunami Warning, which now has been reduced to an advisory. Interesting is that even though the quake occurred at a depth of 40 km, there was still enough movement to create a Tsunami. There was a radio blackout form 20:30 UTC to 21:30 UTC, when the sporadic propagation continues for another 60 min. Propagation was poor for the rest of the day.


    [​IMG]


    Mag Location Time Depth [km] Detected

    M4.9 104 km SSE of Sand Point Alaska 2020-10-19 23:42 27.91 20 m spike

    M4.5 111 km SSE of Sand Point Alaska 2020-10-19 23:41 31.84 20 m spike

    M4.6 133 km SSE of Sand Point Alaska 2020-10-19 23:17 16.02 20 m spike

    M4.8 101 km SE of Sand Point Alaska 2020-10-19 22:20 30.88 20 m, 15 m sporadic propropag.

    M5.9 107 km SSE of Sand Point Alaska 2020-10-19 21:45 37.33 20 m, 15 m sporadic propropag., precursor (-1 h to +1 h)

    M4.5 107 km SSE of Sand Point Alaska 2020-10-19 21:43 33.5 20 m, 15 m sporadic propropag.

    M5.5 133 km SSE of Sand Point Alaska 2020-10-19 21:32 15.52 20 m sporadic propag., precursor (-1 h to +1 h)

    M5.2 133 km SSE of Sand Point Alaska 2020-10-19 21:22 24.04 20 m sporadic propag., precursor (-1 h to +1 h)

    M5.7 92 km SE of Sand Point Alaska 2020-10-19 21:06 34.39 40 m transition waves, all band atten., precursor (-1 h to +1 h)

    M5.8 115 km SSE of Sand Point Alaska 2020-10-19 21:05 27.45 40 m transition waves, all band atten., precursor (-1 h to +1 h)

    M7.5 91 km SE of Sand Point Alaska 2020-10-19 20:54 40.12 40 m transition waves, all band atten., precursor (-7 h to +tbd h)

    M4.6 262 km SSW of Kroya Indonesia 2020-10-19 16:09 10.0 80 m dome, 40 m, 20 m proaqg.

    M5.2 Kepulauan Barat Daya Indonesia 2020-10-19 14:11 369.04 80 m atten., 40 m propag.

    M4.6 36 km ENE of Santa Rosa Peru 2020-10-19 13:18 58.89 40 m, 15 m noise dome, 80 m, 20 m, 10 m spike

    M4.9 south of Africa 2020-10-19 12:20 10.0 80 m propag. , 40 m atten.

    M5.1 197 km SW of Sungai Penuh Indon. 2020-10-19 09:42 36.77 80 m, 40 m propag.

    M5.1 42 km NNW of Sinabang Indonesia 2020-10-19 09:38 12.76 80 m, 40 m propag.

    M4.6 13 km SE of Sa¡nchez Dominican R. 2020-10-19 09:00 10.0 80 m, 40 m propag.

    M4.7 184 km SSE of Tondano Indonesia 2020-10-19 08:22 10.0 80 m propag., 40 m atten.

    M4.8 188 km SW of Sungai Penuh Indonesia 2020-10-19 08:14 10.0 80 m propag., 40 m atten.

    M5.5 187 km SW of Sungai Penuh Indonesia 2020-10-19 07:47 10.0 80 m attnen., precursor (-1 h to +1 h)

    M5.6 191 km SW of Sungai Penuh Indonesia 2020-10-19 07:31 10.0 80 m attnen.

    M4.6 102 km NE of Los Barriles Mexico 2020-10-19 06:25 10.0 80 m atten., 40 m propag.

    M4.5 38 km W of Sandy Bay Honduras 2020-10-19 03:24 10.0 80 m propag., precursor (-1 h to +1 h)



    If you want to receive these earthquakes reports on a regular bases please join the MDSR.io group. Please feel free to forward this message to third parties.


    All the best and 73;


    Alex - VE7DXW
     
  2. WA1GXC

    WA1GXC Ham Member QRZ Page

    When the Moon is in the Seventh House
    And Jupiter's aligned with Mars
    Then peace will guide the planets
    And balums will steer the SWR's
     
    K4PIH, WA8FOZ, KE5OFJ and 2 others like this.
  3. K4KYV

    K4KYV Premium Subscriber Volunteer Moderator QRZ Page

    I'd like to see some explanation of how an earthquake / tsunami could have any effect on the ionosphere. Simultaneous to a solar flare and a mere coincidence?
     
    K0UO likes this.
  4. KL7KN

    KL7KN Ham Member QRZ Page

    I think the guy might have it a bit backwards - the change(s) in the Ionospheric 'current sheet' is what triggers the major quake.

    All about solar forcing of the climate. Other that, the bands seemed pretty dead all day here in Anchorage......
     
  5. KP4SX

    KP4SX Premium Subscriber QRZ Page

    Tsunami, no, but there is some 'electrical/magnetic' activity with an earthquake. That seems to be well-proved. Exactly how that translates to the ionosphere is above my pay grade but I don't discard the concept offhand.
     
    K2BCE, K0IDT and WZ7U like this.
  6. KL7KN

    KL7KN Ham Member QRZ Page

    Check out the Suspicious 0bserves web site. Goes into this in some detail Ben had a major quake alert out early Am for this area...
     
    VE7DXW likes this.
  7. KP4SX

    KP4SX Premium Subscriber QRZ Page

    This one? With a zero in place of 'o'? :confused:
    https://suspicious0bservers.org/
     
    KL7KN likes this.
  8. KL7KN

    KL7KN Ham Member QRZ Page

    Thanks
    My spell checker trys to help

    it too often seems to be drunk...
     
    K8BZ likes this.
  9. VE7DXW

    VE7DXW XML Subscriber QRZ Page

  10. WA1GXC

    WA1GXC Ham Member QRZ Page

    AG6QR likes this.

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