Web services: Focal mechanism solutions

Output focal mechanism solutions in either QuakeML or as a CSV file from the ISC Bulletin. Only the origins which have a focal mechanism solution are returned. There may be multiple focal mechanism solutions for each event. Events with focal mechanism solutions may be selected by region, time, magnitude, depth, and focal mechanism author. Returned data comprise of:

  • Origin data (time, lat, lon, depth) for each focal mechanism solution;
  • Scalar moments;
  • Moment tensor components;
  • Nodal planes;
  • Principal axes;

An overview of the available web services guides can be found on the web services page.



Focal mechanism solutions: URL construction

USAGE:
http://www.isc.ac.uk/cgi-bin/web-db-v4?<output-format><database-choice><geographic-region><time-range>[<depth-limits>][<magnitude-limits>]<fmauthor-limits>

Each <query-option> is comprised of one or more parameters, which are described in detail below. Each parameter needs to be separated by an ampersand (&) as shown in the examples.

Queries or parameters in square brackets ([...]) are optional.

Example query 1:

Output a list of focal mechanism solutions computed by Any agency for events in the ISC Bulletin between 2009-02-22 15:00:00 and 2009-04-22 15:00:00 where the magnitude computed by GCMT >= 5.5

QuakeML format:

http://www.isc.ac.uk/cgi-bin/web-db-v4?out_format=FMQuakeML&request=COMPREHENSIVE&searchshape=GLOBAL&start_year=2009 &start_month=02&start_day=22&start_time=15:00:00&end_year=2009&end_month=04&end_day=22&end_time=15:00:00 &min_mag=5.5&req_mag_agcy=GCMT&req_mag_type=Any&req_fm_agcy=Any

CSV file:

http://www.isc.ac.uk/cgi-bin/web-db-v4?out_format=FMCSV&request=COMPREHENSIVE&searchshape=GLOBAL&start_year=2009 &start_month=02&start_day=22&start_time=15:00:00&end_year=2009&end_month=04&end_day=22&end_time=15:00:00 &min_mag=5.5&req_mag_agcy=GCMT&req_mag_type=Any&req_fm_agcy=Any

Example query 2:

Output a list of focal mechanism solutions computed by GCMT for events, in the reviewed ISC Bulletin between 2009-02-22 15:00:00 and 2009-04-22 15:00:00 where the magnitude >= 5.5 computed by Any agency. Limit events to within 30 degrees of Lat: 25 N; Lon: 36 E

QuakeML format:

http://www.isc.ac.uk/cgi-bin/web-db-v4?out_format=FMQuakeML&request=REVIEWED&searchshape=CIRC&ctr_lat=25&ctr_lon=36&radius=30&max_dist_units=deg &start_year=2009&start_month=02&start_day=22&start_time=15:00:00&end_year=2009&end_month=04&end_day=22 &end_time=15:00:00 &min_mag=5.5&req_mag_agcy=Any&req_fm_agcy=GCMT

CSV file:

http://www.isc.ac.uk/cgi-bin/web-db-v4?out_format=FMCSV&request=REVIEWED&searchshape=CIRC&ctr_lat=25&ctr_lon=36&radius=30&max_dist_units=deg &start_year=2009&start_month=02&start_day=22&start_time=15:00:00&end_year=2009&end_month=04&end_day=22 &end_time=15:00:00 &min_mag=5.5&req_mag_agcy=Any&req_fm_agcy=GCMT

Description of query options:

<output-format>
Parameter name Possible values Description
out_format= <FMQuakeML>|<FMCSV>
  • FMQuakeML (QuakeML) - XML stream. Recommended for use in web services. The documentation can be found on the QuakeML website;
  • FMCSV: A CSV formatted file - one line per focal mechanism solution. A complete description of the output may be found here.


<database-choice>
Parameter name Possible values Description
request= <COMPREHENSIVE>|<REVIEWED>
  • COMPREHENSIVE: Searches the ISC Bulletin;
  • REVIEWED: Searches the Reviewed ISC Bulletin - a subset of the ISC Bulletin, which is reviewed by ISC analysts.


<geographic-region>
Parameter name Possible values Description
searchshape= <GLOBAL>|<RECT>|<CIRC>|<FE>|<POLY>
  • GLOBAL: Events are not restricted by region;
  • RECT: Rectangular search;
  • CIRC: Circular search;
  • FE: Flinn-Engdahl region search;
  • POLY: Customised polygon search.
Dependent parameters if: searchshape=RECT
bot_lat= -90 to 90 Bottom latitude of rectangular region
top_lat= -90 to 90 Top latitude of rectangular region
left_lon= -180 to 180 Left longitude of rectangular region
right_lon= -180 to 180 Right longitude of rectangular region
Dependent parameters if: searchshape=CIRC
ctr_lat= -90 to 90 Central latitude of circular region
ctr_lon= -180 to 180 Central longitude of rectangular region
max_dist_units= <deg>|<km> Units of distance for a circular search: degrees or kilometres
radius= any float or integer Radius for circular search region
  • 0 to 180 if max_dist_units=deg
  • 0 to 20015 if max_dist_units=km
Dependent parameters if: searchshape=FE
srn= 1 to 50 Seismic region number for a Flinn-Engdahl region search
grn= 1 to 757 Geographic region number for a Flinn-Engdahl region search
Dependent parameters if: searchshape=POLY
coordvals= lat1,lon1,lat2,lon2,lat3,lon3,lat4,lon4,lat1,lon1 Comma seperated list of coordinates for a desired polygon. Latitude needs to be before longitude. Coordinates in the western and southern hemispheres should be negative.


<time-range>
Parameter name Possible values Description
start_year= 1904 to 2014 Starting year for events
start_month= 1 to 12 Starting month for events
start_day= 1 to 31 Starting day for events
start_time= 00:00:00 to 23:59:59 Starting time for events (HH:MM:SS)
end_year= 1904 to 2014 Ending year for events
end_month= 1 to 12 Ending month for events
end_day= 1 to 31 Ending day for events
end_time= 00:00:00 to 23:59:59 Ending time for events (HH:MM:SS)


<depth-limits> (Optional)
Parameter name Possible values Description
min_dep= any float or integer Minimum depth of events (km)
max_dep= any float or integer Maximum depth of events (km)
null_dep= [<on>] If set to 'on', events with no known depth will still be output if a min_dep or max_dep is specified.


<magnitude-limits> (Optional)
Parameter name Possible values Description
min_mag= any float or integer Minimum magnitude of events
max_mag= any float or integer Maximum magnitude of events.
null_mag= [<on>] If set to 'on', events with no known magnitude values will still be output if a min_mag or max_mag is specified.
req_mag_type= <Any>|<MB>|<MS>|<MW>|<ML>|<MD> Limit events to specific magnitude types. Please note: the selected magnitude type will search for all possible magnitudes in that category:
E.g. MB will search for mb, mB, Mb, mb1mx, etc
req_mag_agcy= <Any>|<prime>|<CODE> Limit events to magnitudes computed by the selected agency:
  • Any: magnitudes will not be restricted by author;
  • prime: this will limit magnitudes to those associated with the prime (preferred) hypocentre - this is usually but not always the same author as the prime hypocentre;
  • CODE: restricts events with magnitudes computed by a specific agency (e.g. ISC, NEIC, GCMT, JMA, etc.). See here for a full list of agencies.
If a specific CODE is selected, the magnitudes associated to the prime hypocentre will be output in addition to the selected magnitude author.


<fmauthor-limits>
Parameter name Possible values Description
req_fm_agcy= <Any>|<CODE> Limit focal mechanism solutions to those computed by the selected agency:
  • Any: this will return all focal mechanism solutions regardless of author;
  • CODE: restricts focal mechanism solutions to those computed by a specific agency (e.g. GCMT/HRVD, NEIC, JMA, etc.). See here for a complete list of agencies. For a list of agencies that have contributed focal mechanism solutions, see the drop-down menu on the focal mechanism search page.