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.

γ_fit

Required number. Fitted power-law exponent.

±tol

Optional number. Acceptable deviation from two.

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

Check whether a fitted high-frequency spectral decay matches the Brune γ=2 expectation. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Brune-like?

Returned boolean. Whether the fit is within tolerance of γ=2.

Δγ

Returned number. Signed deviation from two.

• 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.
• ±tol 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.

• Brune Corner Frequency Source Model Calculator

  Compute the Brune (1970) circular-crack corner frequency fc = 4.9e6·β·(Δσ/M₀)^(1/3) with β in km/s, Δσ in bar, and M₀ in dyn·cm.

• Brune Source Time Duration From Corner Calculator

  Characteristic source duration from the Brune corner frequency: τ_c ≈ 1/(2π f_c).

• Moment From Spectral Flat Level Calculator

  Compute seismic moment from the low-frequency spectral plateau Ω₀ using the Brune spectral model.