2019 RIDGECREST EARTHQUAKE SEQUENCE

This directory contains the earthquake relocation catalog (out.combloc_1.x) and first motion focal mechanisms (out.focal_1.x) for the 2019 Ridgecrest earthquake sequence.

References:

Lin, G. (2020), Waveform cross-correlation relocation and focal mechanisms for the 2019 Ridgecrest earthquake sequence, Seismol. Res. Lett., 7, doi: 10.1785/0220190277.

Zhang, Q. and G. Lin (2014), Three-dimensional Vp and Vp/Vs models in the Coso geothermal field, California:  seismic characterization of the magmatic system, J. Geophys. Res., 119, doi:10.1002/2014JB010992. 

Location file (out.combloc_1.0) format description:

 38412888 2019   1       1    22   52   15.344  36.11929  -117.66719  5.082   0.59         71      804   185.1     190.0    24.2    33.4        4

   cuspid    year  mo  dy   hr  mn    sec        qlat          qlon       qdep  qmag    npair  ndif  aer_h   aer_z   rer_h   rer_z   iflag

where

38412888 = event identification

2019 = year

         1 = month

         1 = day

         22 = hour

        52 = minute

    15.344 = second

  36.11929 = latitude

-117.66719 = longitude

     5.082 = depth (km, relative to mean sea level)

      0.59 = assigned magnitude 

       71 = number of linked events

      804 = number of differential times used to locate this event

     185.1 = estimated uncertainty in absolute horizontal position (m)

     190.0 = estimated uncertainty in absolute depth (m)

     24.2 = estimated uncertainty in horizontal position relative to the linked events (m)

     33.4 = estimated uncertainty in depth relative to the linked events (m)

​         4 = location method flag (=1 for SCEDC catalog, =3 for 3-D, =4 for waveform cross-correlation)

Focal mechanism file (out.focal_1.0) format description:

  38607032 2019  5 28  2 53  7.090   2.540    36.01100 -117.80666   0.791   185  45 -113   22 22  A   

    cuspid   year mo dy hr mn  sec   qmag       qlat           qlon       qdep    str  dip rak   var1   var2  qual 

where

38607032 = event identification

      2019 = year

         5 = month

         28 = day

         2 = hour

        53 = minute

    7.090 = second

     2.540 = assigned magnitude

  36.01100 = latitude

-117.80666 = longitude

      0.791 = depth (km)

       185 = strike (degree)

        45 = dip (degree)

      -113 = rake (degree)

         22 = variance of each plane, average

         22 = variance of each plane, average

         A = solution quality