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 energy.

M₀ (N·m)

Required number in N·m. Seismic moment.

μ (Pa)

Optional number in Pa. Shear rigidity.

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

Apparent stress σ_app = μ · Es / M₀ in megapascals. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

σ_app (MPa)

Returned number in MPa. Apparent stress.

• 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.
• μ 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 Dip Along Section Line Calculator

  Apparent dip on a section making angle α with the strike: tan(δ_app) = tan(δ)·|sin α|.

• Radiated Energy Moment Ratio Calculator

  Dimensionless ratio of radiated seismic energy to seismic moment.

• AGC Gain Step Artifact Flagger

  Flag windows where automatic-gain-control steps coincide with event energy.