AHEAD European Archive of Historical EArthquake Data

  FDSN event web service  

The AHEAD FDSN event web services provide the event parameters (origin time, epicentral coordinates, magnitude, etc) from the EPICA v1.1 catalogue as preferred origin and magnitude of all the 1000-1899 earthquakes dealt with in AHEAD, available alternative solutions from the catalogues archived in AHEAD can also be queried.

A typical request call submitted to this web service is made by the URL of the service endpoint followed by multiple conditions expressed using well-defined parameters:

https://www.emidius.eu/fdsnws/event/1/query?param1=xxx&param2=xxx&...

If you know the event identifier, you may retrieve its parameters by entering

https://www.emidius.eu/fdsnws/event/1/query?eventid=xxx

Alternatively, you may enter

https://www.emidius.eu/fdsnws/event/1/id/xxxx

Where "xxxx" is the event identifier.

Further information about the web service usage

Index

*** WARNINGS ***

Before downloading data you should carefully read the AHEAD copyright notice, and the disclaimer.
In any case, if you use these data to produce anything that will be made public, you should reference data as downloaded from AHEAD, citing also the original author of the data set.

If you encounter what you think is a bug, find a weird behaviour of the service, or spot errors in the output, you are kindly asked to get in touch with the developer, detailing the issues.

Query builder

To simplify the use of the AHEAD FDSN-event, a convenient, user-friendly graphical front-end called "Query builder" is provided.
Using the Query builder you may learn how to combine the available parameters and get the output from the web service in a human friendly format.

You may find it at:

https://www.emidius.eu/AHEAD/services/query_builder/

Specific event ID request

Parameter Default Description
eventid Type: text, 17 characters

Select a specific event by enetering the event identifier.
AHEAD event identifiers are based on the date (up to minutes), and a progressive number of maximum 3 characters (999).

Event identifier structure (the number is the char position):

  • 1-4 year
  • 5-6 month
  • 7-8 day
  • 9 "_"
  • 10-11 hour
  • 12-13 minutes
  • 14 "_"
  • 15-17 progressive number between 000 and 999

Example:
https://www.emidius.eu/fdsnws/event/1/query?eventid=quakeml:eu.ahead/event/13480125_1530_000

Alternatively, you may use the contracted form

https://www.emidius.eu/fdsnws/event/1/query?eventid=13480125_1530_000

Time constraints

Parameter Default Description
starttime
(abbrev. start) 		Type: text
Unit: date and time *
Allowed values: between year 1000 and 1899-12-31T23:59

Limit to events on or after the specified start time.

endtime
(abbrev. end) 		Type: text
Unit: date and time *
Allowed values: between year 1000 and 1899-12-31T23:59

Limit to events on or before the specified end time.

updatedafter Type: text
Unit: date and time *
Allowable values: greater than 2013-12-31

Limit to events updated in AHEAD after the specified time.
Useful for synchronizing events.

* Date and time can be written in one of the followinf formats
  - YYYY-MM-DDThh:mm
  - YYYY-MM-DDThh
  - YYYY-MM-DD
  - YYYY-MM
  - YYYY

Where
- YYYY, the year, always four-digits (1000-1899)
- MM, the month, always two-digits (01-12)
- DD, the day, always two-digits (01-31)
- T, date-time separator, you must use it if you enter the time
- hh, the hour, always two digits (00-23, AM/PM not allowed)
- mm, the minute, always two digits (00-59)

Notes
- if start is later than end, the system will be fault tolerant and will fix the error;
- due to the historical nature of data contained in AHEAD, seconds are ignored

Example
https://www.emidius.eu/fdsnws/event/1/query?starttime=1742&endtime=1743-02-20

or using abbreviated parameters:
https://www.emidius.eu/fdsnws/event/1/query?start=1742&end=1743-02-20

Geographic constraints

Box area constraints (in alternative to Circular constraints)

Parameter Default Description
minlatitude
(abbrev. minlat) 		-90 Type: float
Unit: decimal degrees
Allowed values: between -90 and 90

Limit to events with a latitude larger than or equal to the specified minimum.

maxlatitude
(abbrev. maxlat) 		90 Type: float
Unit: decimal degrees
Allowed values: between -90 and 90

Limit to events with a latitude smaller than or equal to the specified maximum.

minlongitude
(abbrev. minlon) 		-180 Type: float
Unit: decimal degrees
Allowed values: between -180 and 180

Limit to events with a longitude larger than or equal to the specified minimum.

maxlongitude
(abbrev. maxlon) 		180 Type: float
Unit: decimal degrees
Allowed values: between -180 and 180

Limit to events with a longitude smaller than or equal to the specified maximum.

Example
https://www.emidius.eu/fdsnws/event/1/query?minlat=44.559&maxlat=47.354&minlon=11.942&maxlon=14.513&limit=300

Circular constraints (in alternative to Box area constraints)

Parameter Default Description
latitude
(abbrev. lat) 		0 Type: float
Unit: decimal degrees
Allowed values: between -90 and 90

Specify the latitude to be used for a radius search.

longitude
(abbrev. lon) 		0 Type: float
Unit: decimal degrees
Allowed values: between -180 and 180

Specify the longitude to the used for a radius search.

minradius 0 Type: float
Unit: geographical degrees

Limit to events within the specified minimum number of degrees from the geographic point defined by the latitude and longitude parameters.

maxradius 1 Type: float
Unit: geographical degrees
Allowed values: between 1 and 5

Limit to events within the specified maximum number of degrees from the geographic point defined by the latitude and longitude parameters.

Example
https://www.emidius.eu/fdsnws/event/1/query?lat=45.956&lon=13.227&maxradius=100&limit=300

Magnitude constraints

Parameter Default Description
minmagnitude
(abbrev. minmag) 		Type: float
Unit: magnitude

Limit to events with a magnitude larger than the specified minimum.

maxmagnitude
(abbrev. maxmag) 		Type: float
Unit: magnitude

Limit to events with a magnitude smaller than the specified maximum.

magnitudetype
(abbrev. magtype) 		Type: text
Allowed values: ML, Ms, mb, Mw, nd

Specify a magnitude type to use for testing the minimum and maximum limits.
As of today, AHEAD adopts the EPICA v1.1 1000-1899 catalogue as the preferred solution for magnitudes, consequently all are expressed in Mw.
Code explanation:
- ML, local magnitude
- Ms, surface wave magnitude
- mb, body-wave magnitude
- Mw, moment magnitude
- nd, not determined

Example:
https://www.emidius.eu/fdsnws/event/1/query?minmag=5.6&maxmag=5.9

Data source constraints

Parameter Default Description
catalog Type: text
Allowed values:

Limit to events from a specified catalog.

contributor Type: text
Allowed values:

Limit to events contributed by a specified contributor.

Output data structure

Parameter Default Description
format xml Type: text
Allowed values: text, xml, json, geojson

Specify the format of result, either ‘xml’ (default) or ‘text’.
The xml format is encoded using QuakeML 1.2.
Please note that json will output a geojson, therefore, sending the parameter "&format=json" or "&format=geojson" will be considered identical.

orderby time Type: text
Allowed values: time, time-asc, magnitude, magnitude-asc

Order the result by time or magnitude with the following possibilities:
time: order by origin descending time
time-asc: order by origin ascending time
magnitude: order by descending magnitude
magnitude-asc: order by ascending magnitude

includeallorigins false Type: boolean
Allowed values: true/false (case insensitive)

Specify if all origins for the event should be included. By default only the preferred origin only is included..

includeallmagnitudes false Type: boolean
Allowed values: true/false (case insensitive)

Specify if all magnitudes for the event should be included. By default only the preferred magnitude only is included.

limit 100 Type: integer
Allowed values: between 1 and 6500

Limit the results to the specified number of events.

offset 1 Type: integer
Allowable values:

Return results starting at the event count specified, starting at 1.

nodata 204 Type: boolean
Allowable values: 204, 404

Select status code for “no data”, either ‘204’ or ‘404’.

Example:
https://www.emidius.eu/fdsnws/event/1/query?eventid=quakeml:eu.ahead/event/13480125_1530_000&includeallorigins=true&includeallmagnitudes=true

Non standard parameters

Parameter Default Description
minradiuskm 0 Type: float
Unit: km

Limit to events within the specified minimum number of kilometers (km) from the geographic point defined by the latitude and longitude parameters.

maxradiuskm 50 Type: float
Unit: km
Allowed values: between 1 and 500

Limit to events within the specified maximum number of kilometers (km) from the geographic point defined by the latitude and longitude parameters.

contributorid false Type: text
Allowed values: true/false (case insensitive)

Request the event identifier provided by a contributor.
This parameter will only works when the parameter "contributor" is submitted.

Not supported fdsnws-event parameters

The following parameters will be ignored by the service.

Parameter Default Description
mindepth Type: float
Unit: km

Limit to events with depth more than the specified minimum.

maxdepth Type: float
Unit: km

Limit to events with depth less than the specified maximum.

includearrivals Type: boolean
Allowed values: true/false (case insensitive)

Specify if phase arrivals should be included.