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.

A₀

Required number. Start of epoch A.

A₁

Required number. End of epoch A.

B₀

Required number. Start of epoch B.

B₁

Required number. End of epoch B.

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

Detect whether two channel epochs overlap and quantify the overlap span. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Overlap?

Returned boolean. Whether the epochs share time.

Δt (yr)

Returned number in yr. Overlap length in years.

• 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.

• Repeating Pair Slip Compatibility Checker

  Check whether two repeating events' implied slips are compatible given their areas and moments.

• Array Aperture Moveout Resolution Checker

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

• Basin Edge Surface Waves Checker

  Screen whether the bedrock-to-basin shear-wave velocity contrast reaches an illustrative 2:1 threshold associated with stronger basin-edge effects; geometry is not modeled.