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.

v_r (km/s)

Required number in km/s. Rupture velocity.

β (km/s)

Optional number in km/s. Shear wave velocity.

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

Classify rupture velocity as sub-shear or super-shear relative to β. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

v_r/v_s

Returned number. Velocity ratio.

Regime

Returned string. Rupture regime 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.
• v_r must be at least 0.
• 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.

• Source Rise Time Dislocation Calculator

  Characteristic source timescale estimated as fault width divided by shear-wave velocity; this is a dimensional proxy, not a fitted rupture rise-time model.

• Air Coupled Rayleigh Wave Speed Calculator

  Rayleigh wave speed from shear velocity (≈0.92·β for ν = 0.25) compared with the speed of sound in air.

• Basin Edge Surface Waves Checker

  Screen whether the bedrock-to-basin shear-wave velocity contrast reaches an illustrative 2:1 threshold associated with stronger basin-edge effects; geometry is not modeled.