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BIG quake coming in NOW - Nepal -April 25, 2015

  1. Apr 25, 2015 #1

    davenn

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    Last edited: Apr 25, 2015
  2. jcsd
  3. Apr 25, 2015 #2
    Some people near my place felt the earthquake.
     
  4. Apr 25, 2015 #3

    davenn

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    where are they located ?
     
  5. Apr 25, 2015 #4

    phinds

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    Cool hobby you have, Dave.
     
  6. Apr 25, 2015 #5

    davenn

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    its quite exciting when I see the big signals coming in
    but its tainted with the knowledge that if the quake is on land or near the coast, there is probably dire consequences :frown:
     
  7. Apr 25, 2015 #6

    davenn

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    OK a couple of seismograms ....

    The first one is a raw screen dump taken just prior to the trace overwriting itself

    150425 0611UT M7.8 Himalayas, cntrl Nepal zhi.GIF

    this second one is the processed version with the quake info data added ( timing, depth, location etc)

    150425.062113.zhi.gif

    you can see at the around the 0657 time area that the surface waves were overloading the 16 bit analog to digital converter

    cheers
    Dave
     
  8. Apr 25, 2015 #7

    Astronuc

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    Nepal quake: Hundreds dead, history crumbles, Everest shaken
    http://news.yahoo.com/strong-earthquake-felt-nepals-capital-063242616.html [Broken]
    M7.8 - 34km ESE of Lamjung, Nepal
    http://earthquake.usgs.gov/earthquakes/eventpage/us20002926#general_summary

    M6.6 - 49km E of Lamjung, Nepal
    http://earthquake.usgs.gov/earthquakes/eventpage/us2000292y#general_summary

    There is a swarm of quakes in the 4-5 mag range east of the major quake. Earthquakes are near Nagarkot, Banepa, Panaoti and Kodari.
     
    Last edited by a moderator: May 7, 2017
  9. Apr 25, 2015 #8

    Dotini

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    It is a curious coincidence that this massive earthquake is almost directly antipodal to the massive Calbuco volcanic eruption that began Wednesday afternoon.
     
  10. Apr 25, 2015 #9
    My place is approx. 3500km from nepal. The tremors were felt in many cities in india. They were expecting a second one.
     
  11. Apr 25, 2015 #10

    Evo

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    I hope that you and you loved ones are safe.
     
  12. Apr 26, 2015 #11

    Astronuc

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    Last edited: Apr 26, 2015
  13. Apr 27, 2015 #12

    Astronuc

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  14. Apr 27, 2015 #13
    That depends on your definition of "directly". Katmandu is 27 deg north, Calbuco is 41 deg south; Katmandu is 81 East, Calbuco is 73 west. By my definition that is not even close.
    Cheers
     
  15. Apr 28, 2015 #14
    The most troubling thought in the minds of those affected by this disaster is the lingering fear of another deadly earthquake being round the corner. These kind of events not only cause physical damage, but mentally scar the survivors very deeply as well. The psychological implications are sometimes short termed and lethal - for example, in the 1994 Los Angeles earthquake, a significant portion of deaths were because of cardiac arrests from fright during the earthquake, and not from its after effects. In other cases, the effects are slow and poisonous, eating away at their victims all their lives. Living in dread and sorrow is truly the most terrible way to live indeed. May those subject to this tragedy find solace, and those who have departed from this world eternal tranquility.
     
    Last edited: Apr 28, 2015
  16. Apr 29, 2015 #15

    OmCheeto

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    Fascinating images coming in from the ESA.

     
  17. Apr 30, 2015 #16
    Has anyone heard or read if Everest changed height at all?
     
  18. Apr 30, 2015 #17

    Astronuc

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  19. May 1, 2015 #18

    OmCheeto

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    Also, coincidentally:
    located: 46.06°N 130°W

    But the article continues, and states that the Himalayas are rising about 0.4 inches (1 cm) per year, so a 1 inch drop is pretty insignificant, IMHO.
     
  20. May 2, 2015 #19

    Dotini

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    The ionosphere is very sensitive to solar storms. Turns out, it can be sensitive to earthquakes, too. NASA is reporting that the magnitude 7.8 earthquake in Nepal on April 25th created waves of energy that penetrated the ionosphere and disturbed the distribution of electrons. Note the wave pattern, circled, in the upper panel of this ionospheric electron density plot:

    GPS Data Show How Nepal Quake Disturbed Earth’s Upper Atmosphere

    nepalquakeionosphere20150501.jpg

    The bottom panel of the plot is a "dynamic spectrum." Note the hot spots outlined in black. They show that the ionosphere was ringing with periods of ~2 and ~8 minutes. Presumably, these "tones" are related to atmospheric pressure waves billowing up from the trembling Earth below.

    http://www.nasa.gov/jpl/gps-data-show-how-nepal-quake-disturbed-earth-s-upper-atmosphere
     
  21. May 12, 2015 #20

    davenn

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    Another large quake in Nepal, M 7.3, located around 150 km east of the M 7.8 last month
    I don't think it would be correct to call this an aftershock of the 7.8, as it lies well outside the aftershock zone of that event

    http://www.sydneystormcity.com/seismograms.htm

    150512 0705UT M7.3 estrn Nepal zhi.gif

    It would be much more likely and better to call this a new event, but induced by the changed stress field in the region after the 7.8 Knowledge of these changing stress fields in fault lines after quakes is not new, They came to prominence particularly after the M 6.7 Northridge, California quake of Jan 1994, where remote imaging from satellites clearly showed how the new stresses had moved to the regions beyond either end of the rupture zone. Nothing has happened in those regions in the last 20 years and one would assume ( sometimes a bad thing) that existing stresses plus the addition stress is not enough to cause a new rupture yet.

    Considering the large size of the event last month and the relatively rare occurrence of suck events in this region, it would be easy to conclude that significant stresses in the plate boundary along the Himalayan front have been building for a long period of time, 100+ years. And that, unlike the Northridge situation, it didn't take too much more change in the stress field to the east of the 7.8 to tip the balance and allow this M 7.3 to occur.

    It will be interesting to see in time if studies are done of these events by the USGS or universities, if they show the changes happening in the region

    Regards
    Dave
     
    Last edited: Apr 4, 2016
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