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.

Class

Required string. EMS-98 vulnerability A-F.

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

EMS-98 damage-grade onset bands by building vulnerability class. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

DG1 at

Returned number. Intensity where damage grade 1 typically begins.

DG5 at

Returned number. Intensity where total damage becomes likely.

Note

Returned string. Interpretation guidance.

• 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.

• Response Spectrum Corner Period Band Lookup

  Acceleration- and velocity-controlled period bands scaled by magnitude class.

• Focal Style Rake Band Classifier

  Classify focal-mechanism style from the rake angle using standard Aki-Richards bands.

• Amplification Borcherdt Factor Lookup

  Borcherdt-style short-period amplification factor from NEHRP class.