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.

p (s/°)

Required number in s/°. Horizontal slowness.

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

Convert horizontal slowness (s/deg) to apparent velocity using 111.195 km/deg. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

v_app (km/s)

Returned number in km/s. Apparent velocity across the array.

p_rad (s/rad)

Returned number in s/rad. Slowness in s/radian.

• 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.
• p 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.

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