GRTo-package: Gutenberg-Richter Tools

In GRTo: Tools for the Analysis of Gutenberg-Richter Distributions of Earthquake Magnitudes

Description

Gutenberg-Richter Tools for the analyzis of the properties of distributions of earthquakes in magnitude. Some functions in this package are helpful for the comparison of Gutenberg-Richter b-values. The Schuster's function can be used to highlight blast contamination in earthquake catalogs.

Details

Package:	GRTo
Type:	Package
Version:	1.3
Date:	2015-09-16
License:	GPL
LazyLoad:	yes

Note

Thanks to Paul Friberg (ISTI) for telling us about the bug in the graphical part of bvmed.R. Thanks to Scott Kostyshak (Princeton University) for telling us about the extra bootstrap package dependency. GRTo version 1.2 fixes the issues reported by Paul and Scott. Thanks to Andrew Barbour (USGS) for detecting and fixing minor problems of bvmed.R of version 1.2. In version 1.3, the b-value and an optional staircase line FMD are displayed by BBootComp when a single magnitude file is processed. Version 1.3 also fixes a bug with negative magnitude values. In version 1.3, an option coded by Andrew Barbour allows the processing of data from a list. Willy Aspinall (University of Bristol) highlights bugs in the graphical parts of bvmed and BBootComp: An inappropriate magnitude shift in FMD plots is definitely fixed in version 1.3. Many thanks to Willy!

Author(s)

Daniel Amorese <[e-mail]>, Paul A. Rydelek <[e-mail]> and Jean-Robert Grasso <[e-mail]>

Maintainer: Daniel Amorese <[e-mail]>

References

D. Amorese, "Applying a change-point detection method on frequency-magnitude distributions", Bull. seism. Soc. Am. (2007) 97, doi:10.1785\/0120060181

D. Amorese, J.-R. Grasso and P. A. Rydelek, "On varying b-values with depth: results from computer-intensive tests for Southern California", Geophys. J. Int. (2010) 180, 347-360

Rydelek, P. A. and Hass, L. (1994) On Estimating the Amount of Blasts in Seismic Catalogs with Schuster's Method Bulletin of the Seismological Society of America, Vol. 84, No. 4, pp. 1256-1259.

Siegel, A.F., "Robust regression using repeated medians", Biometrika (1982) 69, 242-244.

Zurn, W. and Rydelek, P. A. (1996) Revisiting the phasor-walkout method for detailed investigation of harmonic signals in time series Surveys in Geophysics, Vol. 15, No. 4, pp. 409-431.

Examples

# Comparison of the b-value for the IDYLLdeep data set.
    BBootComp(finame1=system.file("extdata","IDYLLdeep.data.txt",package="GRTo"),
    finame2=NULL, colid1=15, colid2=NULL,nrep=200,alter=NULL,findtm1=TRUE,
    findtm2=NULL,plot=TRUE, title="IDYLLWILD", tm1=NULL,tm2=NULL)

Example output

Number of events : 1214 

...you just have to wait...

Number of valid replicates :167/200
These replicates concern computations of m_0
Quantiles for threshold magnitude values :
0.92 1.1 1.4
Number of events above m_0 : 747
Quantiles for b-values :
0.81 1 1.2
Median and standard error of bootstrap sample for the b-value :
$b
[1] 0.9951633

$sd
[1] 0.1046509

$m0
50% 
1.1 

$a
[1] 3.972156

Plot in IDYLLWILD_fig.png 

GRTo documentation built on May 2, 2019, 6:46 a.m.