NCSN.MECH(5Q) MISC. REFERENCE MANUAL PAGES NCSN.MECH(5Q) NAME NCSN.MECH - description of focal mechanism (fault plane solution) file format DESCRIPTION FAULT PLANE SOLUTION FORMAT -------------------------- The format of the fault plane solutions produced by FPFIT are HYPO71 summary cards in columns 1-80 augmented with the fault-plane solution parameters. The FORTRAN formats below are to be used for reading the fields. For more information see Reasenberg, P. A., and D. Oppenheimer, 1985, FPFIT, FPPLOT, and FPPAGE: Fortran computer programs for cal- culating and displaying earthquake fault-plane solu- tions, U.S. Geol. Surv. Open-File Rep. 85-739. Cols. Format Data _____ ______ ____ 1-6 3I2, 1X Year, month and day. 8-11 2I2 Hour and minute. 12-17 F6.2 Origin time seconds. 18-20 F3.0 Latitude (deg). 21 A1 S for south, blank otherwise. 22-26 F5.2 Latitude (min). 27-30 F4.0 Longitude (deg). 31 A1 E for east, blank otherwise. 32-36 F5.2 Longitude (min). 37-43 F7.2, 2X Depth (km). 46-50 F5.2 Magnitude. See col. 80 for code 51-53 I3 Number of P & S times with weights greater than 0.1. 54-57 F4.0 Maximum azimuthal gap. 58-62 F5.1 Distance to nearest station (km). 63-67 F5.2 RMS travel time residual. 68-72 F5.1 Horizontal error (km). 73-77 F5.1, 2X Vertical error (km). 80 A1, 1X If data source is Hypoinverse, then code designates type of magnitude posted in cols. 46-50. L=ML based on above location, B=ML from UC Berkeley, C=coda, A=amplitude 82-84 F3.0, 1X Dip direction (downdip azimuth in degrees,clockwise from north) 86-87 F2.0 Dip angle in degrees down from horizontal 88-91 F4.0, 2X Rake in degrees: 0=left lateral, 90=reverse, +-180=right lateral, -90=normal 94-97 F4.2, 1X Solution misfit value. 0=perfect fit, 1=perfect misfit (never exceeds 0.5 in reality). 99-101 I3, 1X Number of first motion observations used in solution 103-107 F5.2, 1X Solution misfit value + 90% confidence estimate. Useful for testing whether restricted solutions are within uncertainty region of free solution 109-112 F4.2, 1X Station distribution ratio (0-1). Lower numbers indicate data lie near nodal planes. Sun Release 4.1 Last change: 15 June 1993 1 NCSN.MECH(5Q) MISC. REFERENCE MANUAL PAGES NCSN.MECH(5Q) 114-117 F4.2, 2X (# of machine picks)/(# of hand picks) 120-121 F2.0, 1X maximum half-width of 90% confidence range of strike 123-124 F2.0, 1X maximum half-width of 90% confidence range of dip 126-127 F2.0 maximum half-width of 90% confidence range of rake 128 A1 Convergence flag: C=no convergence; otherwise blank 129 A1 Multiple solution flag: *=multiple; otherwise blank 130-139 I10 Event ID # found in Hypoinverse archive file AUTHOR This document is maintained by David Oppenheimer (oppen@alum.wr.usgs.gov) Last revised: July 12, 1994. Modi- fied by Doug Neuhauser, Seismographic Station, UC Berkeley. Sun Release 4.1 Last change: 15 June 1993 2