The FDSN availability web service returns time span information of what timeseries are available at the SCEDC archive.

It implements the /extent and /query service methods. The FDSN availability web service specification can be found here.

Extent produces lists of available time extents (earliest to latest) for selected channels (network, station, channel,location) and time ranges. Extents can be queried for continuous and triggered waveforms as well as seismic phase data.

Query produces lists of continuous time spans for selected channels (network, station, channel, location) and time ranges. Query is available only for continuous waveform data.

Availability information is refreshed daily. The following data are availabile for
/extent:

• triggered records from Jan 1977 - present
• continuous records from Oct 1999 - present
• phase records from Jan 1932 - present

/query

• continuous records (*H*, *N* and *L*) from Jan 01 2011 - April 28, 2020

Note: Query end point updates are made on a daily basis but they are made at a delay to allow gaps in the archive to be filled. The most recent records are from 6 days ago.

Output formats supported are text, GeoCSV, JSON and request(query endpoint only). Please see help for details.

Please see Help for available query parameters.

Sample queries

Continuous waveforms

Extent information for all channels for network CI, station AGO
https://service.scedc.caltech.edu/fdsnws/availability/1/extent?network=CI&station=AGO&asset=continuous

Extent information for all channels for network CI and station WBS for continuous waveforms in geocsv format
https://service.scedc.caltech.edu/fdsnws/availability/1/extent?network=CI&station=WBS&format=geocsv

Extent information for all channels for network CI and station RPV for continuous waveforms in json format
https://service.scedc.caltech.edu/fdsnws/availability/1/extent?network=CI&station=RPV&format=json

Triggered waveforms

Extent information for network CI, station PASC, channel HHE for a given time interval
https://service.scedc.caltech.edu/fdsnws/availability/1/extent?network=CI&station=PASC&channel=HHE&starttime=2000-01-01T00:00:00&endtime=2018-01-01T00:00:00&asset=triggered

Phase data

Seismic phase information for network CI, for a given time interval
https://service.scedc.caltech.edu/fdsnws/availability/1/extent?network=CI&starttime=1932-01-01T00:00:00&endtime=1934-01-01T00:00:00&asset=phase

URL Builder

Input form parameters and notice the URL field at the bottom change dynamically. Click on the URL to run your query.

Note: Query end point updates are made on a daily basis but they are made at a delay to allow gaps in the archive to be filled. The most recent records are 6 days from today. This means that today, continuous data for seismic channels (*H*, *N* and *L*) from 2011/01/01 - 2020/08/17 are available for queries.

Channel

net

sta

loc

cha

start

end

Output

Format

text geocsv json request

URL: /fdsnws/availability/1/query?nodata=404&net=&sta=&cha=

The FDSN availability web service specification can be found here.

URLs:

The URL used for extent and query endpoints and the available query parameters are described below.

• /fdsnws/station/1/extent?[query-parameters]
• /fdsnws/station/1/query?[query-parameters]

where query-parameters:

Empty/No parameters		Will return availability of all channels at SCEDC.
net="network"	Optional	Specify SEED network code, example net=CI.
sta="station"	Optional	Specify SEED station code, example sta=BAK.
loc="location"	Optional	Specify SEED location code mask, example: loc=00. substitute dash characters for white space, example: loc=--.
cha="channel"	Optional	Specify SEED channel code mask, example: cha=BHE.
start=YYYY-MM-DDThh:mm:ss	Optional	Specify channels operating after this date.
end=YYYY-MM-DDThh:mm:ss	Optional	Specify channels operating before this date.
asset="asset"	Optional	Specify the asset type i.e. continuous, triggered or phase. Default is continuous. Extent endpoint ONLY, as the query endpoint only serves continuous data.
format=text | geocsv | json | request	Optional	Specify output format. Default is text. text output format contains one time span per line with fields separated by spaces. geocsv output format is a text format designed to contain enhanced metadata. json output format is defined using the JSON schema. request output format contains one time span per line in the FDSN web service POST-style request format. Valid for query endpoint only.
nodata=204|404	Optional	Specify which HTML status code is returned when no data is found (Default is 204).

POST Usage:

/extent and /query can be accessed via HTTP POST. All parameters available in GET are also allowed in POST.

When using a data file for sending requests, the general form of a POST request is one or more global parameter=value lines, followed by any number of sncl i.e net sta loc cha values and optionally, time window selection lines. The order of parameters in the sncl lines is important and must be net sta loc chan [start end]. Sncl line(s) are required.

Generic form of a post data file

The following table shows which parameters can be global for POST requests when submitting parameters via a data file.

global: parameter can be specified only once per POST data file in the form of parameter=value pair.

non-global: parameter must be specified in line like so net sta loc cha [start end]
any: parameter can be specified globally or in line

Parameter	Scope	Endpoint
net	non-global	extent, query
sta	non-global	extent, query
loc	non-global	extent, query
cha	non-global	extent, query
start	any	extent, query
end	any	extent, query
asset	global	extent
format	global	extent, query
nodata	global	extent, query

Alternatively, request parameters can also be submitted as a string, consisting of parameter=value pairs joined together by ampersand. The general format in such a case is
net=NN&sta=SSSSS&cha=CCC&loc=LL&start=YYYY-MM-DDTHH:MM:SS&end=YYYY-MM-DDTHH:MM:SS&format=[text|json|geocsv].

Example data files for POST request

Start and end times can be specified globally, or individually with each channel or as a mix of global and individual time ranges.

Using curl or wget for POST requests with extent and query endpoints

curl and wget Unix utilities can be used to submit POST requests and the save the results in a text file.

Timespans for /extent and /query endpoints

• /extent
  The timespan displayed for a channel is the earliest and latest miniseed data points that fall within the specified start and end times. This includes any gaps that might be present. If no start and end times are specified, all available data is retrieved.
• /query
  For a channel, the query endpoint displays lists of continuous data, one continuous data segment per row. Hence, a channel may display several rows of availability depending on how gappy the data was for the queried time period.