M8 {ssM8}R Documentation

Run the M8 Algorithm

Description

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.

Usage

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)

Arguments

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.

Details

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.

Value

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

Author(s)

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

See Also

decluster.M8, M8.series, M8.TIP

Examples

#   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)
[Package ssM8 version 2.1-3 Index]