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.

λ₁

Required number. Largest principal eigenvalue (arbitrary units).

λ₂

Required number. Intermediate eigenvalue.

λ₃

Required number. Smallest eigenvalue.

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

Decompose ordered moment-tensor eigenvalues into isotropic and deviatoric amplitudes, then split the deviatoric share into double-couple and CLVD components; the three reported percentages sum to 100. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

DC% (%)

Returned number in %. Double-couple share of the deviatoric part.

CLVD% (%)

Returned number in %. Compensated linear-vector dipole share.

ISO% (%)

Returned number in %. Isotropic (trace) share of the full tensor.

• 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.
• 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.

• Scalar Moment From Deviatoric Eigenvalues Calculator

  Scalar seismic moment from tensor eigenvalues: M̄ = √(Σλᵢ²/2).

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• Coda Q Scattering Intrinsic Split Calculator

  Split total attenuation into intrinsic and scattering parts via 1/Q_total = 1/Q_intrinsic + 1/Q_scattering.