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.

t (s)

Required number in s. One-way time to the reflector.

V_avg (m/s)

Required number in m/s. Average velocity above the target.

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

Convert an event's one-way time to depth with a constant average velocity. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

z (m)

Returned number in m. Depth of the target.

• 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.
• t must be at least 0.
• V_avg 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.

• Velocity Model Layer Cake Two Way Time Depth Converter

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  Layer thickness from normal-incidence two-way time and interval velocity.