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.

Es (J)

Required number in J. Radiated seismic energy.

M₀ (N·m)

Required number in N·m. Seismic moment.

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

Dimensionless ratio of radiated seismic energy to seismic moment. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Es/M₀

Returned number. Dimensionless ratio.

• 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.
• Es must be at least 0.
• M₀ 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.

• Apparent Stress Energy Ratio Calculator

  Apparent stress σ_app = μ · Es / M₀ in megapascals.

• Asperity Area Fraction Scaling Calculator

  Asperity area fraction A_a/A₀ as a power-law function of seismic moment, capped at the physical upper bound of one.

• Average Moment Rate From Moment Duration Calculator

  Average seismic moment release rate over a specified source duration: Ṁ₀ = M₀/T.