GEOFON offers access to seismic waveform and station
metadata using the FDSN web services,
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.
Returns response-level information as FDSN StationXML for all BH* channels present at all current GEOFON stations. This may be imported directly into SeisComP.
Warning: this is relatively large (> 4MB).
For many temporary networks, the FDSN-assigned network code is shared between multiple networks.
For these you may need to specify a year range to avoid unwanted unrelated stations.
Our list of networks archived at GEOFON includes the start and end year for each network.
The next example shows this:
Requests a list of events occuring in the first twelve hours of 2021 (UTC).
Note specification of "&format=text" in the query string
(after "?" in the URL above).
Response is a text (CSV) file, with columns separated by the "|" character.
There are seven events.
The first row is a header, displaying the meaning of each column.
We do not yet use the EventType parameter to distinguish between types of event, so they are all reported as "earthquake".
Requests a list of events between 21 and 25 December 2016 (inclusive).
Additional parameters in the "query string" (after "?" in the URL above)
serve to constrain the set of events selected by geographical region and magnitude.
As above, the response is a text (CSV) file, with columns separated by the '|' character.
There are currently 12 events matching the selection criteria.
Requests QuakeML for the same event as above, but adds "includefocalmechanism=true".
The response is the same as above but now includes information about the preferred published focal mechanism(s), if there is one.
Requests QuakeML for the event
but adds "includeallfocalmechanisms=true".
The response now includes all published focal mechanism(s).
For GEOFON events currently there is not more than one focal mechanism per event.
Our service includes several similar additional request parameters
which are extensions of the FDSN specification.
For details, see
Access to restricted data with webservices
Stations with restricted channels are available through the
auth extension to FDSN webservices.
The current implementation supports the
Web Services Version 1.2 Specification.
There are a few special features, described further at the
SeisComP online documentation for fdsnws
[Specific page for the 4.7.3].
In particular you may add &nodata=404 to return a
HTTP response code 404 instead of the usual 204, should no data be found.
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 objects which fdsnws-event will return. This is also currently 250000 objects. The note below gives additional details.
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.
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 (see figure).
Size limits for fdsnws-event.
You can request the entire set of GEOFON events as a text (CSV) file with a single request, using format=text.
For the richer QuakeML output more care is needed.
The number of events you can receive in a single request depends on the web service options you employ in your request.
To ensure adequate capacity for all users of our service, we have limits
on request size in place. These are implemented as a limit on the total number
of objects involved, which is much greater than the number of events,
as it can include many origins, magnitudes, focal mechanisms, picks,
for each event.
This is related to the size of the event - larger events, detected at more
stations, and with more analysis, generate more objects than small ones.
If your request is too large, then the server responds with
Error 413: Request Entity Too Large
In particular, a request to the /query method with no restrictions at all
(https://geofon.gfz-potsdam.de/fdsnws/event/1/query) will result in this 413 error.
As a guide, the following requests should be successful:
With both picks AND focal mechanisms requested, even a time span
of a month is too long. Confining ourselves to the largest magnitude
events (those with the most objects) only, but with no time constraint
(i.e. includeallfocalmechanisms=true&includefocalmechanism=true&includearrivals=true&includepicks=true&minmag=...), succeeds for large enough magnitudes.
Currently the smallest magnitude for which the request above succeeds is around M=6.6; this contains 494 events, is 88 MB, and takes over six minutes.
Values of minmag smaller than this in the request result in the 413 error response.
For M=7.0, there are 211 events in a 40MB XML response file.