Computing Fault Slip Rates from NeoKinema Output: (P. Bird, 2009.12.03; revised 2016.11.06) ------------------------------------------------------------------------- The low-resolution (trace-averaged) offset rates in output file f_[token].nko often occur in pairs, for faults of oblique slip (transtensional or transpressional). The way that these should be combined depends on the capital-letter indicator for the type of offset-rate (D, L, N, R, S, P, T) in column 6 of each line of the file. Offset-rates N are throw rates (relative vertical velocity components), and need to be converted to dip-slip rates using the fault dip angle (or the default normal-fault dip of 55 degrees), before you combine them in the Pythagorean formula with the strike-slip rate L or R. Offset rates T are also throw rates (for thrusts) and need to be converted to dip-slip rates using the fault dip angle (or the default thrust-fault dip of 20 degrees), before you combine them in the Pythagorean formula with the strike-slip rate L or R. Offset rates P are compressional heave rates (relative horizontal components) in the direction perpendicular to the fault trace; they should also be converted to dip-slip rates before combining with the strike-slip component L or R. Offset rates S (Subduction) are like P rates: they are compressional heave rates (relative horizontal velocities) in the direction perpendicular to the fault trace. They should be converted to dip-slip rates (typically, using the assumed dip of 14 degrees for the seismogenic parts of subduction zones), prior to combining this dip-slip rate with any strike-slip L or R in the Pythagorean formula. Offset rates D are extensional heave rates (relative horizontal velocities) in the direction perpendicular to the fault trace; they should also be converted to dip-slip rates before combining with the strike-slip component L or R. If the "fault" is really a sea-floor spreading center (or dike intrusion center), then computing a slip-rate may not be meaningful at all. TO MAKE ALL OF THESE COMPUTATIONS MORE CONVENIENT, YOU CAN USE MY UTILITY PROGRAM Rake_and_Sliprate_per_Fault for post-processing NeoKinema output files, and producing a tab-delimited ASCII table which is convenient for loading into Excel (or similar spreadsheets) for final formatting and display.