ShakeMap Instrument Intensity PGV Converter
Convert PGV to instrumental intensity with the Wald et al. (1999) ShakeMap relation MMI = 3.51·log₁₀(PGV in cm/s) + 2.35, clamped to the displayed MMI range 1–10.
Description
Convert PGV to instrumental intensity with the Wald et al. (1999) ShakeMap relation MMI = 3.51·log₁₀(PGV in cm/s) + 2.35, clamped to the displayed MMI range 1–10.
ShakeMap Instrument Intensity PGV Converter is a focused tool for the following task. Convert PGV to instrumental intensity with the Wald et al. (1999) ShakeMap relation MMI = 3.51·log₁₀(PGV in cm/s) + 2.35, clamped to the displayed MMI range 1–10. It reports MMI, Shaking from the values you provide rather than inventing measurements, coefficients, or professional judgment that are not part of the input.
When to use ShakeMap Instrument Intensity PGV Converter
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.
- PGV (cm/s)
- Required number in cm/s. Peak ground velocity.
The cited overview of Seismic intensity scales supplies background for the terminology and domain context used by this tool.1
How ShakeMap Instrument Intensity PGV Converter works
Convert PGV to instrumental intensity with the Wald et al. (1999) ShakeMap relation MMI = 3.51·log₁₀(PGV in cm/s) + 2.35, clamped to the displayed MMI range 1–10. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.
- MMI
- Returned number. Instrumental Modified Mercalli intensity.
- Shaking
- Returned string. Qualitative shaking descriptor.
Limitations and assumptions
- 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.
- PGV must be at least 0.
- Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.
Alternative or Complementary approaches
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.
References
-
Seismic intensity scales — Wikipedia contributors
Similar or alternative tools
- Intensity PGA Wald 1999 Table Lookup
Wald et al. (1999) MMI-to-PGA bounds used in ShakeMap ground-motion to intensity conversion.
- JMA Intensity From PGV Converter
Japan Meteorological Agency instrumental intensity from PGV (cm/s): I_JMA = 2.68·log₁₀(PGV) + 2.29 (approx).
- Instrument Response Gain DB Lookup
Convert a dimensionless gain factor to decibels (20·log₁₀).