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.

A/A₀

Required number. Observed over initial amplitude.

f (Hz)

Required number in Hz. Frequency.

x (km)

Required number in km. Path length.

v (km/s)

Required number in km/s. Wave velocity.

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

Infer quality factor Q from amplitude decay along a propagation path: A = A₀·exp(−π f x / (Q v)). Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Q

Returned number. Quality factor.

t* (s)

Returned number in s. Attenuation operator t* = x/(Qv).

• 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.
• A/A₀ must be at least 0.
• f must be at least 0.
• x must be at least 0.
• v 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.

• Kappa Site Anelastic Attenuation Calculator

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• Apparent Dip Along Section Line Calculator

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