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.

W (km)

Required number in km. Down-dip fault width.

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]

Characteristic source timescale estimated as fault width divided by shear-wave velocity; this is a dimensional proxy, not a fitted rupture rise-time model. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

τ_r (s)

Returned number in s. Source rise time.

• 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.
• W 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.

• Time Dependent Conditional Probability Calculator

  Approximate time-dependent rupture probability from a Weibull renewal model, using k = (mean/std. dev.)² and a scale chosen to preserve the supplied mean; this is not a Brownian-passage-time calculation.

• 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.

• Near Fault Fling Step Velocity Pulse Calculator

  Fling-step peak velocity from static slip and rise time: v ≈ Δu / τ.