Use this seismology calculation to reproduce a stated convention, screen observations, or compare scenarios whose units, coordinate conventions, catalog selection, and model assumptions are known.

φ_CFF (°)

Required number in °. Tidal Coulomb stress phase at event time.

SS/NF?

Required boolean. True for strike-slip/normal, false for thrust.

The cited overview of Fault (geology) supplies background for the terminology and domain context used by this tool.^[1]

Check whether an event's tidal phase falls in the promoting window for its fault style. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Promoting

Returned boolean. Whether the phase promotes failure.

Band

Returned string. Phase-band classification.

• Earth structure, source geometry, path effects, site response, instrument response, catalog completeness, uncertainty, and the fitted range can dominate the accuracy of simplified seismic calculations.
• φ_CFF must be at least -180.
• Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.

For analysis or hazard decisions, retain uncertainty and provenance and compare the result with waveform processing, calibrated regional models, and guidance from qualified seismologists or the responsible agency.

• Tsunamigenic Magnitude Threshold Checker

  Screen whether an event magnitude exceeds common tsunamigenic thresholds for its setting.

• Array Aperture Moveout Resolution Checker

  Check whether array aperture resolves the expected moveout across the slowness band.

• Average Radiation Factor Boore Boatwright Lookup

  Boore-Boatwright style average radiation factors for P and S waves over the focal sphere.