Approximation to Earthquake Spectrum

Freq.            log(events)
----- ------------------------------
    1 *
    2                  *
    4                         *
    8                             *
   16                              *
   32                              *
   64                             *
  128                            *
  256                           *
  512                          *
 1024                        *
 2048                      *
 4096                   *
 8192                 *
16384              *
32768            *
65536          *

Freqency unit is events/day.  Computed from time series of magn. 4.5 and greater starting 1 Jan 2004 to late 18 Sep 2021.