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.

M

Required number. Source magnitude.

R (km)

Required number in km. Distance from source to shore.

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

First-order far-field tsunami runup scaling with magnitude and distance (heuristic exponents). Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

R_u (m)

Returned number in m. Estimated maximum runup.

Band

Returned string. Qualitative hazard band.

• 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.
• R 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.

• Magnitude Scaling Saturation Check Tool

  Flag whether a rupture length implies magnitude beyond the empirical saturation limit (~M7.8) of simple linear scaling.

• Tsunami Seafloor Vertical Offset Calculator

  First-order seafloor vertical offset from dip-slip on a fault: u ≈ slip·sin(dip).

• Damping Response Spectrum Heuristic Scaling

  Heuristic spectral scaling from 5% to another damping ratio: F = (0.05/ζ)^0.25.