Directivity Pulse Duration Near Source Calculator
Forward-directivity timescale for a unilateral rupture, L·(1/v_r − 1/β), assuming the site lies along strike in the rupture direction.
Description
Forward-directivity timescale for a unilateral rupture, L·(1/v_r − 1/β), assuming the site lies along strike in the rupture direction.
Directivity Pulse Duration Near Source Calculator is a focused tool for the following task. Forward-directivity timescale for a unilateral rupture, L·(1/v_r − 1/β), assuming the site lies along strike in the rupture direction. It reports T_p from the values you provide rather than inventing measurements, coefficients, or professional judgment that are not part of the input.
When to use Directivity Pulse Duration Near Source
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.
- L (km)
- Required number in km. Fault length.
- 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 Seismology supplies background for the terminology and domain context used by this tool.1
How Directivity Pulse Duration Near Source works
Forward-directivity timescale for a unilateral rupture, L·(1/v_r − 1/β), assuming the site lies along strike in the rupture direction. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.
- T_p (s)
- Returned number in s. Pulse duration at near-fault sites.
Limitations and assumptions
- 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.
- L must be at least 0.
- v_r must be at least 0.
- Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.
Alternative or Complementary approaches
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.
References
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Seismology — Wikipedia contributors
Similar or alternative tools
- Directivity Narrowband Pulse Period Calculator
First-order rupture-duration proxy for directivity pulse period: T_p ≈ L/v_r.
- Strike-Slip Seismic Moment and Average Dislocation Estimate
Seismic moment and average dislocation estimate for a strike-slip rupture: geodetic moment M₀ = μ·A·ū and a half-slip (ū/2) offset scale; this heuristic does NOT compute the Okada (1992) elastic half-space spatial displacement field.
- 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.