README
Created January 7, 2015 by N. Lewandowski
Revised February 25, 2015 by N. Lewandowski

This Readme file documents the data in the Earthquake Catalog appendix text file Attachment_F-2.txt. 


The file Attachment_F-2.txt provides an earthquake focal mechanism catalog for M>0.0 for the period January 1, 1968 to June 3, 2013. 

N. Lewandowski downloaded the catalog from the Northern California Earthquake Data Center (NCEDC) website (http://www.ncedc.org/ncedc/catalog-search.html) on June 3, 2013. The downloaded catalog includes earthquakes that occurred in the area of 34 degrees N to 35.75 degrees N and 121.5 degrees W to 120.514 degrees W.

The earthquakes are identified by an ID found in the Hypoinverse archive file. 

Attachment_F-2.txt contains 5,495 rows of data; the first 13 rows of the file contain the search parameters. There are 141 columns.
The search parameters listed in Attachment_X-2.txt include the following: 
Row 3, 4 are start and end time
Rows 5, 6 are minimum and maximum latitude 
Rows 7, 8 are minimum and maximum longitude
Row 9 is "etype" - event type; "E" is earthquake
Row 10 is "rflag" - describes how observations were generated ("A" for automatically; "H" by a human) and if is interim ("I") or has been finalized ("F") 
Row 11 is "system" - describes how parameters were chosen; "selected" is entered by user
Row 12 is "format" - output format; "ncfpraw" is fault plane solutions in FPFIT format


The following text describes the columns in Attachment_F-2.txt. The column descriptions listed below are included on the NCEDC website (Oppenheimer, 1999) and apply to fault plane solutions in FPFIT format.
Columns 1 through 8 are the year, month, and day the earthquake occurred
Columns 10 through 19 are the hour, minute, second the earthquake occurred
Columns 22 through 22 are latitude (degrees)
Column 23 is hemisphere; S for south, blank or N for north
Columns 25 through 28 are latitude (minutes)
Columns 29 through 32 are longitude (degrees)
Column 33 is hemisphere; E for east, blank for west
Columns 34 through 38 are longitude (minutes)
Columns 39 through 45 are depth (km)
Columns 48 through 52 are magnitude; magnitude type is defined in column 82
Columns 53 through 55 are the number of P&S times with weights greater than 0.1
Columns 56 through 59 are the maximum azimuthal gap
Columns 60 through 64 are the distance to the nearest station (km)
Columns 65 through 69 are the RMS travel time residual
Columns 70 through 74 are the horizontal error (km)
Columns 75 through 79 are the vertical error (km)
Column 82 is the code that designates the type of magnitude listed in columns 48 through 52; L is based on the location (ML), D is duration magnitude (Md), and W is moment magnitude (MW)
Columns 84 through 86 are the dip direction (downdip azimuth in degrees,clockwise from north)
Columns 88 and 89 are the dip angle in degrees down from horizontal
Columns 90 through 93 are the rake in degrees: 0=left lateral, 90=reverse, +-180=right lateral, - 90=normal
Columns 96 through 99 are the solution misfit value. 0=perfect fit, 1=perfect misfit 
Columns 101 and 103 are the number of first motion observations used in the solution
Columns 105 through 109 are the solution misfit value + 90% confidence estimate
Columns 111 through 114 are the station distribution ratio (0-1), where lower numbers indicate data lie near nodal planes.
Columns 116 through 119 are the ratio of number of machine picks to number of hand picks
Columns 122 and 123 are the maximum half-width of 90% confidence range of strike
Columns 125 and 126 are the maximum half-width of 90% confidence range of dip
Columns 128 and 129 are the maximum half-width of 90% confidence range of rake
Column 130 is the convergence flag; C = no convergence; otherwise blank
Column 131 is the multiple solution flag; * = multiple; otherwise blank
Columns 132 through 141 are the event ID number found in Hypoinverse archive file




