Using the GEOFON/FDSN web services

GEOFON offers access to seismic waveform and station metadata using the FDSN web services. Requests may be submitted by anyone, using any suitable web client.

We offer the following services from geofon.gfz-potsdam.de:

  • fdsnws-station - Inventory for all networks archived at GFZ. A current list of networks is available. In particular, networks which are coordinated as part of EIDA but not archived here are not available by web service. Their metadata can be accessed using our data portal or by other methods.
  • fdsnws-dataselect - Real time and archive data for those networks archived at GFZ (not other EIDA data centres). You can check availability with our availability database.

A few example URLs are given below.

We do not offer an fdsnws-event earthquake parameter service, but you may find our popular eqinfo event catalog helpful.

Examples

fdsnws-station

http://geofon.gfz-potsdam.de/fdsnws/station/1/version
Returns the string "1.1.0".
http://geofon.gfz-potsdam.de/fdsnws/station/1/query?net=GE&level=station
Returns basic information as FDSN StationXML about all stations in the GEOFON seismic network.
http://geofon.gfz-potsdam.de/fdsnws/station/1/query?net=GE&sta=BKB&cha=BHZ&level=channel
Returns channel-level information as FDSN StationXML for the BHZ channel at GEOFON station Balikpapan, Kalimantan.
http://geofon.gfz-potsdam.de/fdsnws/station/1/query?net=GE&cha=BH?&start=2016-01-01&level=response
Returns response-level information as FDSN StationXML for all BH* channels present at all current GEOFON stations. This may be imported directly into SeisComP 3. Warning: this is relatively large.

fdsnws-dataselect

http://geofon.gfz-potsdam.de/fdsnws/dataselect/1/version
Returns the string "1.1.0".
http://geofon.gfz-potsdam.de/fdsnws/dataselect/1/query?net=GE&sta=BKB&cha=BHZ&starttime=2011-03-11T06:00:00Z&endtime=2011-03-11T06:05:00Z
Returns 300 seconds of data from 0600 UTC on 11 March 2011, for the BHZ channel at GEOFON station Balikpapan, Kalimantan.
http://geofon.gfz-potsdam.de/fdsnws/dataselect/1/query?net=GE&sta=KBU&starttime=2012-06-01&endtime=2012-06-04&nodata=404
Requests data from the GEOFON station in Kabul, Afghanistan; since this is not available, the service returns "404 Not Found" instead.

Access to restricted data with webservices

Stations with restricted channels are available through the new (2016) auth extension to FDSN webservices.

Notes

  1. The current implementation supports the version 1.1 specification. [Web Services Version 1.1 Specification] There are a few special features, described further at the SeisComP online documentation for
    fdsnws
    [Specific page for the 2013.340 release]. In particular you may add
    &nodata=404
    to return a HTTP response code 404 instead of the usual 204, should no data was found.
  2. There are some limits on the size of requests which will be accepted:
    • There is a maximum number of objects which fdsnws-station will return. This is currently 250000 objects.
    • There is a maximum number of samples which fdsnws-dataselect will return. This is currently 1000 million samples.
    There are also some limits on the total number of simultaneous users. If you plan to send many automatic requests, please arrange to send them slowly to avoid inconveniencing other users.
  3. New (December 2016) The /auth method allows access using token-based authentication. See FDSN web services authentication and authorization at GEOFON.
  4. The actual data returned depends on availabiliity.
  5. Assuming we have complete data for the time window you request, the fdsnws-dataselect service will send you unmodified mini-SEED records covering all the time you have requested.
    Demonstrate mini-SEED records returned in response to a time window request
    Each SEED record is generally 512 bytes, and contains a variable number of samples (depending on compression and sample rate). For BH (20 sps) data, a record may cover a time segment of around 10-20 seconds. If you request data with start_time=tstart, you will receive the entire mini-SEED record which includes tstart for each channel. Such records, and those at the end of the time window tend, are shown in bright green in the figure above. Thus you will receive data corresponding to the dark green and light green regions, but not the yellow regions. Note that the time windows returned may differ between channels (BHE, BHN, BHZ above), and may contain gaps or overlaps.