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.

λ (°)

Required number in °. Rake of the first nodal plane.

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

Classify focal-mechanism style from the rake angle using standard Aki-Richards bands. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Style

Returned string. Strike-slip, normal, reverse, or oblique variant.

Sense

Returned string. Dominant slip sense description.

• 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.
• 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.

• Synthetic Strike-Slip Polarity Data Generator

  Generate synthetic P-wave polarity training data for a strike-slip-dominant focal mechanism.

• Average Radiation Factor Boore Boatwright Lookup

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

• Double Couple P T Axis Plunge Style Shortcut

  Shortcut P/T axis plunges for ideal focal styles (strike-slip, normal, reverse).