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.

h (m)

Required number in m. Mean water depth.

ρ (kg/m³)

Optional number in kg/m³. Water density.

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

First-order Coulomb stress perturbation under a reservoir load: Δσ ≈ ρ·g·h. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Δσ (bar)

Returned number in bar. Vertical stress change at the base of the reservoir.

Note

Returned string. Pore-pressure coupling reminder.

• 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.
• h must be at least 0.
• ρ 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.

• Coulomb Stress Change On Receiver Plane Calculator

  Coulomb failure stress change on a receiver plane: ΔCFF = Δτ + μ′·Δσn (tension positive convention).

• Strain Drop Slip Over Length Stress Drop

  First-order stress drop from the strain-drop picture: Δσ ≈ μ·(D/L).

• Directivity Narrowband Pulse Period Calculator

  First-order rupture-duration proxy for directivity pulse period: T_p ≈ L/v_r.