M8                   package:ssM8                   R Documentation

_R_u_n _t_h_e _M_8 _A_l_g_o_r_i_t_h_m

_D_e_s_c_r_i_p_t_i_o_n:

     This function runs the M8 algorithm, i.e. calls the function
     'M8.series' to calculate the seven time series, calls the function
     'M8.TIP' to calculate the Times of Increased Probabilities, and
     finally, optionally calls the function 'plot.M8' to plot all seven
     series plus an eighth critical series.

_U_s_a_g_e:

     M8(catalogue, M0, centrelong=mean(catalogue[, "longitude"]),
        centrelat=mean(catalogue[, "latitude"]), radius=radius.M8default(M0),
        minday=catalogue[1, "time"],
        start.series=datetimes(year=(years1(minday) + 12), month=1, day=1,
        hour=0, minute=0), training="user", end.training=NA, time.breaks=Inf,
        running.total=12, smoother=6, TIP.length=10, plotit=TRUE,
        title="M8 Series and TIPs", debug=FALSE)

_A_r_g_u_m_e_n_t_s:

catalogue: the mainshock catalogue (created by the 'decluster.M8'
          function), with the number of aftershocks in following 14
          days. 

      M0: numeric. The aim of the algorithm is to predict earthquakes
          with a magnitude greater than or equal to M0. 

centrelong: longitude of the centre of the circle of interest. 

centrelat: latitude of the centre of the circle of interest. 

  radius: circle of interest radius. The default radius is
          55.5*{exp(M0-5.6)+1}. 

  minday: Julian date, events earlier than this are not used in
          analysis. By default, all the data are used. 

start.series: Julian date of end point of the first bin from which the
          series are generated. Since the series are calculated using
          bins (defined by 'time.breaks'), the 'start.series' must
          coincide with an end point of one of the bins. The M8 default
          is six month bins. 

training: has three possible modes: '"moving"', '"user"', and '"all"'.
          See Details in 'M8.series' for further explanation. 

end.training: Julian date for the end of the training period. This date
          should be the end point of a bin. This is only used when the
          training mode is '"user"'. 

time.breaks: a vector of Julian dates that give the bin boundaries for
          calculating the series. The (M8) default bin length is 6
          months. Care must be taken that the arguments 'minday',
          'start.series' and 'end.training' coincide with a breakpoint
          in the vector 'time.breaks'. The breaks should also be at
          regular intervals. 

running.total: by default, the series are calculated with a six year
          running total, i.e.12 half years, thus the M8 default is 12. 

smoother: integer, denoting the length of the smoothing window. The
          series are smoothed at a given point by taking their maximum
          value over previous values within this window. The default
          value is 6 (i.e. three years). 

TIP.length: is the duration of the TIP or "Time of Increased
          Probability". The M8 default is 5 years (i.e. 10 time
          intervals), and is independent of M0. 

  plotit: logical. If set to 'TRUE' then seven plots for each of the
          seven smoothed series are generated. There is also a plot of
          the largest earthquake in each 6 month interval, together
          with the critical series. The default is 'TRUE'. 

   title: character string giving a title for the page of plots. The
          default is '"M8 Series and TIPs"'. 

   debug: logical. The default is 'FALSE'. 

_D_e_t_a_i_l_s:

     See Details in 'M8.series' for an explanation of how the M8 series
     are calculated, and 'M8.TIP' for how the Times of Increased
     Probabilities are calculated.

_V_a_l_u_e:

     The same object as that returned by the function 'M8.TIP'.

_A_u_t_h_o_r(_s):

     Li Dongfeng, 1997; modified by Maaike Vreede, 1998.

_S_e_e _A_l_s_o:

     'decluster.M8', 'M8.series', 'M8.TIP'

_E_x_a_m_p_l_e_s:

     #   Requires the package ssNZ
     require(ssNZ)

     as.catalogue(subsetrect(NZ, minday=julian(1,1,1965),
                             maxday=julian(1,1,2000), minmag=4.5),
                  catname="NZ45")

     decluster.M8(NZ45, cutoff.mag=4.5, decluster.name="NZ.mainshocks")

     savpar <- par(no.readonly=TRUE)
     temp <- M8(NZ.mainshocks, M0=7.0, minday=julian(y=1965, x=1, d=1),
                start.series=julian(y=1975, x=1, d=1), centrelong=176, 
                centrelat=-39, end.training=julian(y=2000, x=1, d=1))
     par(savpar)

