Event Catalogs

Event Query allows the user to search our entire event catalog database. SeismiQuery is our advanced database search tool and provides the user with a number of search options.

NEICALRT

List distributed by NEIS (National Earthquake Information Service) of the USGS via email and used to trigger the IRIS SPYDER® system. These events are NOT included in the "PREFERRED" catalog algorithm because they are redundant (of FINGER) and do not include all events reported by FINGER.

 

FINGER

List distributed by NEIS (National Earthquake Information Service) of the USGS through the "finger quake@gldfs.cr.usgs.gov" service. The earthquakes on the "quake" list have been reviewed by a seismic analyst. However, in the interest of timeliness, locations and magnitudes are entered once and not updated on the list.. This list contains data for the past 7 days. Once an event rolls off the list it appears on the QED (see next definition).

PDE-Q/QED

Quick Epicenter Determinations - distributed by the USGS NEIS 7 days behind real time. These data are extremely preliminary and the parameters of the earthquakes are subject to change as more data are used to relocate the earthquakes. The QED rolls over to the WHDF (see next definition).

 

PDE-W/WHDF

Weekly Hypocenter Data File - distributed by the USGS NEIS. Covering the time period following the Monthly data up to four weeks behind the current week. The Weekly PDE (Preliminary Determinations of Epicenters) data are replaced by the Monthly PDE data as soon as they become available.

 

PDE/MHDF

Monthly Hypocenter Data File - distributed by the USGS NEIS. This list is the most complete computation of hypocenters and magnitudes done by the USGS NEIC. It is normally produced a few months after the events occur. The publication is called "preliminary" because the "final" computation of hypocenters for the world is considered to be the Bulletin of the International Seismological Centre (ISC), which is produced about two years after the earthquakes occur.

 

ISC/ISCCD

Bulletin of the International Seismological Centre (ISC). List of earthquakes two years behind real time.

 

ANF/ANFR

Earthquake locations published by the USArray Array Network Facility (ANF). The ANF also publishes event phase readings which are available from the DMC. The "R" in the ANFR catalog indicates the final Reviewed publication.

 

NCEDC

Bulletin of the Northern California Earthquake Data Center.

 

SCEDC

Bulletin of the Southern California Earthquake Data Center.

 

PREFERRED (SeismiQuery option only)

When this selection is made in SeismiQuery, the resulting list of events will include events selected from the catalog that is considered to be most accurate for that time period. The order in which the catalogs are listed above is the reverse order in which events will be selected as "preferred." (That is, the ISCCD being most preferred and so on.)

SPYDER

SPYDER® is IRIS DMC's near-real-time data retrieval system. SPYDER® data is not QCed but is available almost immediately after an event. To browse and request SPYDER® data, use WILBER II — our Web-based request tool.

 

FARM

Fast Archive Recovery Method - FARM is IRIS DMC's readily-accessible seismic event data repository (delayed, QC'd, full data set).

• The most notable events are larger than a magnitude of 5.5 (Mw). For this reason, the DMC routinely pre-assembles data from earthquakes that exceed magnitude 5.7 at any depth, and for events down to magnitude 5.5 if the depth is greater than 100 km. These pre-assembled data sets are called FARM Products and consist of data collected from stations all over the world and from many different networks.

• Since most seismic phase arrivals occur within 60 minutes of the initial phase arrival at a seismic station, we extract a 60 minute window for broadband, mid period, and short period channels. Long period windows are a function of magnitude, tuned to record the maximum number of Rayleigh phases for larger events. FARM products become available 6 weeks to 3 months after the event and are most easily accessed using WILBER II.