The event Web service provides access to contributed origin and magnitude estimates in QuakeML format. Events may be filtered e.g. by hypocenter, time and magnitude parameters. The request type is HTTP-GET and HTTP-POST. Please refer to http://www.fdsn.org/webservice for a complete service description.
Every request to query must be bounded in time: it must include starttime and/or endtime, or select a single event via eventid. Requests without any of these are rejected with HTTP 400. limit alone is not sufficient.
Queries without a time constraint force a sort of the entire event catalog on the backend database (several minutes per request) and degrade the service for all users.
Example — instead of:
/fdsnws/event/1/query?format=text&limit=100&orderby=time
request a sliding time window, e.g. the last 24 hours:
/fdsnws/event/1/query?format=text&orderby=time&starttime=2026-07-08T22:00:00&endtime=2026-07-09T22:00:00
Clients polling for recent events should advance such a window on each request rather than asking for the “latest N” events. Please also keep polling intervals reasonable (≥ 60 s).