The "Boxer" program was written by P. Gasperini in the April 1999. It is a revised and simplified version of several computer codes which, starting from 1993, have been developed by the author, and with the contribution of F. Bernardini and G. Ferrari, to compute focal parameters of earthquakes from macroseismic data and have been actually used to make the computation of the Catalogo dei Forti Terremoti in Italia dal 461 a.C. al 1990 [Boschi et al. 1995, 1997] and of the BSSA paper [Gasperini et al., 1999]. The present version of the program also took advantage of important improvements by G. Vannucci and G. Valensise (who also suggested the name of the program).

While the computed macroseismic epicenter, epicentral intensity and azimuth fully coincide with the published papers, the magnitude may be slightly different (some tenth of magnitude unit at most) due to some differences in the relative weighting of intensity classes. A description of the procedure to determine the azimuth and to draw the "boxes" representing the seismogenic structure can be found in Gasperini et al. [1999]. More details on the computation of epicenter and of the magnitude can even be found in Gasperini and Ferrari [1995,1997,2000]

The tag identifies the purpose of the card and must be written beginning with column 1 with either upper or lower case characters. A percent character ("%") in column 1 indicate comments and make the card content to be ignored by the program.

An alphabetical list of the available option cards tag follows:

AZPAR - Assign parameters of the azimuth computation algorithm

CRAMCOEF — Assigns coefficient of the distance weighting formula in the azimuth algorithm

FILE - Define the name of the macroseismic input data file

FORMATE - Specifies the Fortran format of the event summary records of the input data file

FORMATI - Specifies the Fortran format of the intensity point records of the input data file

LENGCOEF - Assigns coefficients of the fault length formula

MAGCOEF - Assigns coefficients of the magnitude formula using the radius method

MAPINFO - Direct the program to produce graphic input files for MAP-INFO.

M-I0COEF - Assigns coefficients of the magnitude-intensity formula

OUTLOOK - Direct the program to write a fixed format summary file

OUTPUT - Select type of output

SELMAG - Defines the minimum magnitude for azimuth computations.

USEMAG - Direct the program to use the magnitude reported on the event summary record

WIDCOEF - Assigns coefficients of the fault width formula

A detailed explanation of the format of each option is given below:

Assigns the values of the minimum allowed number of data-points and the maximum allowed number of half degree decrements with respect to maximum intensity in the azimuth computation algorithm (see: Gasperini et al. [1999]).

Parameter field:

1) Name: Nmin

2) Name: Ndecr

Additional data cards

None

Example

1 11 21

AZPAR 6 4

Assigns the values to the coefficients of the CRAM [Berardi et al., 1993] formula to compute the distance weights in the azimuth determination algorithm (see: Gasperini et al. [1999])

where is the difference between epicentral and local intensity and is the epicentral distance. Default values were empirically estimated for Italy by Gasperini et al. [1999].

Parameter field:

1) Name: Acram

2) Name: Bcram

Additional data cards

None

Example

1 11 21

CRAMCOEF -0.3 1.1

Assigns the name of the macroseismic data file containing the event summary and the intensity points.

Parameter field:

1) Name: Filename

Additional data cards:

none

Example

1 11

FILE INPUT2.DAT

Specifies the Fortran format of the event summary records of the input data file. The format must be embedded in parenthesis. It must contain 9 fields in the following order: Year (integer), Month (integer), Day (integer), Hour (integer), Minute (integer), Second (integer), Epicentral Area (alphanumeric), Magnitude (real), Number of intensity points (integer). Tabulation (T fields) can be used to accomplish this order if different.

Parameter field:

none

Additional data cards:

Card 1

1. Name: Formate

1 11

FORMATE

(8x,I5,5I3,1X,A20,64x,F3.2,T58,I4)

Parameter field:

none

Additional data cards:

Card 1

6. Name: Formati

1 11

FORMATI

(48X,2F8.4,F6.1,T30,A20)

where is the moment magnitude and is the fault length in kilometers. Default values are empirical estimates for subsurface rupture length of "all types of fault" according to Wells and Coppersmith [1993].

Parameter field:

1) Name: Alen

2) Name: Blen

Additional data cards

None

Example

1 11 21

LENGCOEF -2.11 0.65

Assigns the values of the coefficients of the Sibol et al [1987] formula to compute the macroseismic equivalent moment magnitude (Hanks and Kanamori, 1979) with the radius method (see Gasperini et al. [1999]) for different intensity class. Default values are empirical estimates for Italy from the data of the Catalogo dei Forti Terremoti in Italia dal 461 a.C. al 1990 [Boschi et al.. 1995, 1997].

Parameter field:

1. Name: Ncoef

Additional data cards

Card 1

1. Name: Aiv(1)

2) Name: Coef(1,1)

3) Name: Coef(1,2)

3) Name: Coef(1,3)

Cards 2 to Ncoef

Repeat the above format for different intensity classes (in increasing order of intensity).

Example:

(The example values are the default ones)

1 11 21 31 41 51 61

MAGCOEF 10

2. 3.554 0.025 0.024

3. 3.422 0.038 0.023

4. 3.034 0.074 0.019

4.5 4.340 0.022 0.015

5. 3.277 0.103 0.012

6. 3.829 0.070 0.015

6.5 4.198 0.094 0.009

7. 4.394 0.091 0.009

7.5 5.078 0.110 0.000

8. 5.348 0.116 0.000

Direct the program to produce graphic input files for MAP-INFO mapping code.

Assigns the values of the coefficients of the formula to compute macroseismic equivalent moment magnitude (Hanks and Kanamori, 1979) from epicentral intensity alone when data not enough to apply the radius method (see: Gasperini et al. [1999])

where is the moment magnitude and the epicentral intensity. Default values have been empirically estimated on the basis of the italian magnitude-intensity database by Rebez and Stucchi [1999]

Parameter field:

1) Name: Aint

2) Name: Bint

Additional data cards

None

Example

1 11 21

M-I0COEF 1.5 0.5

Direct the program to write a fixed format summary file

Select type of output (1- normal output, 2-long output)

Parameter field:

1) Name: Iout

Additional data cards

None

Example

1 11 21

OUTPUT 2

Direct the program to compute the azimuth only for earthquakes with magnitude larger than a given threshold.

Parameter field:

1. Name: Aminmg

Function: minimum magnitude threshold above which the azimuth is computed

Additional data cards

none

Example

1 11

SELMAG 5.5

Direct the program to use the magnitude value specified on the event summary line instead of the computed one.

Parameter field:

none

Additional data cards

none

Example

1 11

USEMAG

where is the moment magnitude and is the fault length in kilometers. Default values are empirical estimates for subsurface rupture width of "all types of fault" according to Wells and Coppersmith [1993].

Parameter field:

1) Name: Alen

2) Name: Blen

Additional data cards

None

Example

1 11 21

WIDCOEF -1.3 0.29

Boschi, E., G. Ferrari, P. Gasperini, E. Guidoboni, G. Smriglio and G. Valensise (1995). Catalogo dei forti terremoti in Italia dal 461 a.C. al 1980, ING-SGA, Bologna, 973 pp. and a CD-ROM.

Boschi, E., E. Guidoboni, G. Ferrari, G. Valensise and P. Gasperini (1997). Catalogo dei forti terremoti in Italia dal 461 a.C. al 1990, ING-SGA, Bologna, 644 pp. and a CD-ROM.

Gasperini, P., and G. Ferrari (1995). Stima dei parametri sintetici, in: E. Boschi et al. (Eds.), Catalogo dei Forti Terremoti in Italia dal 461 a.C. al 1980, ING-SGA publ., 96-111.

Gasperini, P., and G. Ferrari (1997). Stima dei parametri sintetici: nuove elaborazioni, in: E. Boschi et al. (Eds.), Catalogo dei Forti Terremoti in Italia dal 461 a.C. al 1990, ING- SGA publ., 56-64.

Gasperini, P., and G. Ferrari (2000). Deriving numerical estimates from descriptive information:the computation of earthquake parameters. Annali di Geofisica, 43, 729-746.

Hanks T. C. e Kanamori H. (1979). A moment magnitude scale. J. Geophys. Res., 84, 2348-2350.

Rebez A. and Stucchi M. (1999). Determinazione dei coefficienti della relazione tabellare Io/Ms, in

Catalogo Parametrico dei Terremoti Italiani, ING,GNDT,SGA,SSN, 90 pp..

Sibol, M. S., G. A. Bollinger and J. B. Birch (1987). Estimations of magnitudes in central and eastern North America using Intensity and Felt Area, Bull. Seism. Soc. Am., 77, 1635-1654.

Wells, D. L. and K. J. Coppersmith (1994). New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement, Bull. Seism. Soc. Am., 84, 974-1,002.

Sample INPPARM.DAT file:

% INPUT TEST FILE

%

% USES CATALOGUE MAGNITUDES

USEMAG

% COMPUTE AZIMUTH ONLY IF M>=5.5

SELMAG 5.5

FILE TEST

FORMATE (8x,I5,5I3,1X,A20,64x,F3.2,T58,I4)

FORMATI (48X,2F8.4,F6.1,T30,A20)

Sample of TEST.DAT file

11 DI 79 08 25 07 Area vesuviana CFTI 6 80 80 40.800 14.380 A 622 38 540 28 M 569 22 48 50043

000018 Miseno 40.7861 14.0853 7.5

000015 Napoli 40.8554 14.2604 7.5

000019 Nola 40.9257 14.5287 8.0

000020 Sorrento 40.6243 14.3782 7.0

000017 Nocera Inferiore 40.7428 14.6418 8.0

000021 Salerno 40.6788 14.7654 5.0

1841 DI 1930 07 23 00 08 Irpinia CFTI 511 100 100 41.050 15.370 A 678 08 660 30 M 670 05 O 672 04 498 1543 30013

000052 Brescia 45.5439 10.2144 4.6

000640 Salù 45.6057 10.5223 2.5

000100 Vicenza 45.5491 11.5492 2.5

000740 Volterra 43.4019 10.8590 4.0

008220 Cortona 43.2746 11.9864 2.0

012798 Molino 43.5659 13.3363 2.0

000611 Ancona 43.6031 13.5074 2.5

008255 Filottrano 43.4344 13.3510 2.0

001765 Sirolo 43.5214 13.6201 2.0

005099 Civitanova Marche 43.3066 13.7296 4.0

001502 Macerata 43.2994 13.4524 3.0

001503 Matelica 43.2557 13.0094 3.0

001504 Recanati 43.4029 13.5499 3.5

001505 Tolentino 43.2095 13.2827 3.5

012799 Ussita 42.9438 13.1362 3.0

002335 Visso 42.9304 13.0878 2.5

OUTSUMMARY.DAT file

DATE TIME LON LAT ME LOCALITY NTOT NAZ AZIMUTH RAYLEIGH KUIPER

08/25/ 79 07:00 40.79 14.39 5.7 Area vesuviana 6 5 087+-053 uniform uniform

07/23/1930 00:08 41.05 15.36 6.7 Irpinia 511 16 109+-011 <0.01 <0.01

05/07/1984 17:50 41.67 14.06 5.6 Appennino abruzzese 911 3 152+-034 <0.10 uniform

OUTFULL.DAT file

Input Cards:

% INPUT TEST FILE

%

% USES CATALOGUE MAGNITUDES

USEMAG

% COMPUTE AZIMUTH ONLY IF M>=5.5

SELMAG 5.5

FILE TEST

FORMATE (8x,I5,5I3,1X,A20,64x,F3.2,T58,I4)

FORMATI (48X,2F8.4,F6.1,T30,A20)

Parameters summary

Input file: TEST.DAT

Event fmt: (8x,I5,5I3,1X,A20,64x,F3.2,T58,I4)

Intensity fmt: (48X,2F8.4,F6.1,T30,A20)

Magnitude coef:

Intensity a b c

2.0 3.55400 .02500 .02400

3.0 3.42200 .03800 .02300

4.0 3.03400 .07400 .01900

4.6 4.34000 .02200 .01500

5.0 3.27700 .10300 .01200

6.0 3.82900 .07000 .01500

6.5 4.19800 .09400 .00900

7.0 4.39400 .09100 .00900

7.5 5.07800 .11000

8.0 5.34800 .11600

Cram coef (a, b): -.460 .930

M-Io coef (a, b): .940 .560

Length coef (a, b): -2.440 .590

Width coef (a, b): -1.010 .320

Use magnitude on event card (if not 0)

Compute Boxes only for M .GE. 5.50

********************************************

Events summary

********************************************

Event : 79 8 25 7 0 0 5.7 Area vesuviana

No. of intensity data : 6

Computed epicenter : 40.7948 14.3891

No. of data used : 5

Maximum intensity : 8.0

Epicentral intensity : 8.0

Moment magnitude : 6.11

No. of radii used : 1

Used magnitude : 5.69

Fault length (Km) : 8.3

Fault width (Km) : 6.5

Fault azimuth (deg) : 86.5

Azimuth std : 52.7

No. of data used : 5

Rayleigh Test : uniformity ho hypothesis not rejected

Kuiper Test : uniformity ho hypothesis not rejected

Box vertices : 40.8130 14.3385 40.8176 14.4364

40.7720 14.3418 40.7765 14.4397

********************************************

Event : 1930 7 23 0 8 0 6.7 Irpinia

No. of intensity data : 511

Computed epicenter : 41.0536 15.3588

No. of data used : 3

Maximum intensity : 10.0

Epicentral intensity : 10.0

Moment magnitude : 6.69

Magnitude std : .07

No. of radii used : 9

Used magnitude : 6.72

Fault length (Km) : 33.5

Fault width (Km) : 13.8

Fault azimuth (deg) : 108.9

Azimuth std : 10.9

No. of data used : 16

Rayleigh Test : uniformity ho hypothesis rejected s.l. < 0.01

Kuiper Test : uniformity ho hypothesis rejected s.l. < 0.01

Box vertices : 41.1438 15.1887 41.0465 15.5666

41.0607 15.1510 40.9633 15.5289

********************************************

Event : 1984 5 7 17 50 0 5.6 Appennino abruzzese

No. of intensity data : 911

Computed epicenter : 41.6664 14.0571

No. of data used : 3

Maximum intensity : 8.0

Epicentral intensity : 8.0

Moment magnitude : 5.82

Magnitude std : .09

No. of radii used : 8

Used magnitude : 5.64

Fault length (Km) : 7.7

Fault width (Km) : 6.2

Fault azimuth (deg) : 151.6

Azimuth std : 33.9

No. of data used : 3

Rayleigh Test : uniformity ho hypothesis tent rej s.l. < 0.10

Kuiper Test : uniformity ho hypothesis not rejected

Box vertices : 41.7064 14.0584 41.6453 14.1026

41.6875 14.0117 41.6265 14.0559