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.

CC̄

Required number. Average waveform cross-correlation.

N

Required integer. Number of events in the group.

CV

Required number. Coefficient of variation of inter-event times.

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

Screen whether an event group qualifies as a repeating-earthquake family via waveform similarity and regularity. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Family?

Returned boolean. Whether the group qualifies as a repeater family.

Driver

Returned string. Likely driving process hint.

• 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.
• CC̄ must be at least 0.
• N must be at least 0.
• CV 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.

• Tsunamigenic Magnitude Threshold Checker

  Screen whether an event magnitude exceeds common tsunamigenic thresholds for its setting.

• 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.

• MS MB Explosion Discrimination Note Lookup

  First-order Ms/mb discrimination screen for event source type.