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.

M

Required number. Magnitude.

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

Gutenberg-Richter energy relation log₁₀Es(J) = 1.5·M + 4.8. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Es (J)

Returned number in J. Radiated seismic energy.

×31.6

Returned number. Energy ratio per unit magnitude.

• 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.

• Gutenberg Richter A Value Annual Normalization

  Annualized GR productivity: a = log₁₀(N_year) + b·Mc.

• Network Detection Threshold Coverage Calculator

  Illustrative magnitude-of-completeness screening relation M_min ≈ 1.5 + log₁₀(r/km) using a detection radius of 1.5 times station spacing; it is not a calibrated network threshold.

• Characteristic Earthquake Magnitude Window Lookup

  Estimate characteristic magnitude from a fault length using the Wells & Coppersmith strike-slip relation.