Use this geological calculation for a transparent first-pass interpretation of measured rock, soil, fluid, well, stratigraphic, isotopic, geophysical, or seismic data under an explicitly selected model.

S-P interval

S-P arrival-time interval in seconds.

Vp

P-wave velocity in kilometers per second.

Vs

S-wave velocity in kilometers per second.

Epicentral distance from the S-minus-P arrival-time interval: d = dt * (vP * vS) / (vP - vS) for a common straight-ray path. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Distance

Epicentral distance in kilometers.

• Seismic magnitudes, moments, travel times, velocities, resolution, and energy depend on instrument correction, Earth model, phase picking, geometry, attenuation, radiation pattern, bandwidth, and calibration range. Magnitude scales are not universally interchangeable.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Compare independent measurements and models, retain units and analytical metadata, propagate uncertainty, and validate interpretations against logs, cores, maps, laboratory data, or field observations.

• Travel Time P Wave Calculator

  Straight-ray P-wave first-arrival time t = d / vP with distance and velocity in kilometers and kilometers per second.

• Travel Time S Wave Calculator

  Straight-ray S-wave arrival time t = d / vS with distance and velocity in kilometers and kilometers per second.

• Jacob Drawdown Calculator

  Compute the Cooper-Jacob straight-line approximation of drawdown in meters from discharge (m3/day), transmissivity (m2/day), radial distance (m), storativity and time (days).