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.

E_i

Required list. Per-interval a²·Δt contributions.

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

Significant duration bracketing the 5–95% Arias interval from per-interval energy contributions. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

N_5–95

Returned number. Number of intervals spanning 5–95% of Arias.

• 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.

• Arias Intensity Duration Proxy Calculator

  Arias intensity proxy I_a ≈ (π/2g)·∫a² dt approximated by PGA² times effective duration.

• Recurrence Interval Slip Rate Event Slip Calculator

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

• AGC Gain Step Artifact Flagger

  Flag windows where automatic-gain-control steps coincide with event energy.