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.

Region

Required string. ETS region class (cascadia, nankai, alaska, mexico).

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

Typical episodic-tremor-and-slip recurrence and migration parameters by region class. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Interval (wk)

Returned number in wk. Mean episode recurrence.

Duration (wk)

Returned number in wk. Typical single-episode duration.

V_mig (km/d)

Returned number in km/d. Tremor migration speed.

• 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.

• NEHRP Fundamental Period Site Lookup

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• Recurrence Interval Slip Rate Event Slip Calculator

  Characteristic recurrence from per-event slip and long-term slip rate: T = D/V.