Magnitude 6.6 – EASTERN HONSHU, JAPAN

A strong magnitude 6.6 aftershock from the March 11, 2011 earthquake shook Japan this morning at 08:16:13 UTC.  The waveform recorded on my seismograph in Ohio is dominated by a very large SS phase, the S phase reflected once from the earth’s surface.  My Lehman seismograph is very sensitive to transverse phases approaching from the north and south but I haven’t figured out yet why they are so large on some earthquakes and not on others.

Here are the travel time results from USGS site:

  DATE-(UTC)-TIME    LAT    LON     DEPTH MAG   Q   COMMENTS
  2011/04/11 08:16:13  37.01N 140.48E  10.0 6.6      US: EASTERN HONSHU, JAPAN
   Expected 20s period surface wave amplitude [  2.13E+01 µm]  [  6.70E+00 µm/s]
   Expected 1s period body wave amplitude     [  2.72E-01 µm]  [  1.71E+00 µm/s]

 delta   azimuth (degrees clockwise from north)
 (deg)      eq-to-station     station-to-eq
 93.58           31.0             327.3

                 travel   arrival time
    #  code      time(s)  dy hr mn sec
    1  P          796.21   0  8 29 29
    2  PcP        796.59   0  8 29 29
    3  pP         799.55   0  8 29 32
    4  sP         800.83   0  8 29 33
    5  PP        1020.63   0  8 33 13
    6  PKiKP     1081.81   0  8 34 14
    7  pPKiKP    1085.24   0  8 34 18
    8  sPKiKP    1086.50   0  8 34 19
    9  SKiKP     1296.49   0  8 37 49
   10  SKSac     1430.40   0  8 40  3
   11  pSKSac    1434.99   0  8 40  7
   12  sSKSac    1436.27   0  8 40  9
   13  SKKSac    1449.14   0  8 40 22
   14  S         1464.92   0  8 40 37
   15  ScS       1466.21   0  8 40 39
   16  pS        1469.32   0  8 40 42
   17  sS        1470.66   0  8 40 43
   18  SP        1538.67   0  8 41 51
   19  PS        1540.06   0  8 41 53
   20  PKKPbc    1820.61   0  8 46 33
   21  PKKPdf    1821.08   0  8 46 34
   22  SS        1843.61   0  8 46 56
   23  SKKPdf    2035.90   0  8 50  8
   24  PKKSdf    2037.15   0  8 50 10
   25  SKKPbc    2040.17   0  8 50 13
   26  PKKSbc    2041.42   0  8 50 14
   27  SKKSdf    2251.78   0  8 53 44
   28  SKKSac    2259.68   0  8 53 52
   29  P'P'df    2313.97   0  8 54 46
   30  S'S'ac    3177.60   0  9  9 10
   31  S'S'df    3178.55   0  9  9 11
   32  LQ        2375.07   0  8 55 48
   33  LR        2635.99   0  9  0  8
 
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s