Base Dictionary

For the base GeoJSON dictionary, the GMP specification adds four additional keys:

version

The version of the ground motion packet (string; required).

creation_time

File creation timestamp in UTC in ISO 8601 extended format (i.e., with separators between the year, month, and day, and the hour, minutes, and seconds, and with a “T” between the date and time). Example: “2022-01-16T14:12:32.470Z” (string; required).

event

An optional dictionary containing earthquake properties for the earthquake associatd with the metrics given in this file (dictionary; optional).

provenance

A SEIS-PROV-compliant provenance document (dictionary; required). The contents of this dictionary will be discussed in more detail later, but the full specification is given here.

Note that in this document, we will list the GMP elements as above, indicating the element type and whether or not it is required in parentheses. The following example illustrates these top-level additions to the GeoJSON format.

{
  "type": "FeatureCollection",
  "event": {
    ...
  },
  "features": [
    ...
  ],
  "version": "0.1dev",
  "provenance": {
    ...
  }
}