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.

M₀,A (N·m)

Required number in N·m. Moment of event A.

A_A (km²)

Required number in km². Patch area of A.

M₀,B (N·m)

Required number in N·m. Moment of event B.

A_B (km²)

Required number in km². Patch area of B.

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

Check whether two repeating events' implied slips are compatible given their areas and moments. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

D_B/D_A

Returned number. Implied slip ratio.

Compatible?

Returned boolean. Whether the ratio is within ±20 percent of unity.

• 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.
• M₀,A must be at least 0.
• A_A must be at least 0.
• M₀,B must be at least 0.
• A_B 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.

• Slip vs Time Predictable Checker

  Check whether observed recurrence interval and slip are consistent with a loading-rate-driven recurrence model.

• Array Aperture Moveout Resolution Checker

  Check whether array aperture resolves the expected moveout across the slowness band.

• Dataless Channel Epoch Overlap Checker

  Detect whether two channel epochs overlap and quantify the overlap span.