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.

x_i

Required list. Event eastings.

y_i

Required list. Event northings.

a (km)

Required number in km. Square cell edge.

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

Bin event eastings/northings into a square grid and report cell occupancy statistics. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

cells

Returned integer. Number of distinct occupied cells.

max

Returned integer. Highest count in any cell.

N/cell

Returned number. Mean events per occupied cell.

• 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.
• a 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.

• Catalog Depth Histogram Binner

  Bin hypocentral depths into fixed-width bins with an out-of-range tail count.

• First Motion Polarity Beachball Quadrant Picker

  Summarize P-wave first-motion polarity statistics into beachball quadrant occupancy.

• Survey Design Fold Count CMP Binning Summary

  Nominal 2-D end-on acquisition fold N·Δr/(2·Δs) and CMP interval Δr/2 for a regular source/receiver grid; actual edge fold and irregular geometry require explicit trace counting.