Table of Contents

The ANSS Comprehensive Catalog (ComCat) contains earthquake source parameters (e.g. hypocenters, magnitudes, phase picks and amplitudes) and other products (e.g. moment tensor solutions, macroseismic information, tectonic summaries, maps) produced by contributing seismic networks. This comprehensive collection of seismic information will eventually replace the ANSS composite catalog hosted by the Northern California Data Center; however, historic regional seismic network catalogs have not yet been fully loaded.

Important digital catalogs of earthquake source parameters (e.g. Centennial Catalog, Global Centroid Moment Tensor Catalog) are currently being loaded into ComCat. New and updated data is added to the catalog dynamically as sources publish or update products. Check back for updates.

Data Availability

Data Availability as of 2015-03-19:

Currently loading (available soon):


We use a GeoNames dataset to reference populated places that are in close proximity to a seismic event. GeoNames has compiled a list of cities in the United States where the population is 1,000 or greater (cities1000.txt). This is the primary list that we use when selecting nearby places. In order to provide the public with a better understanding for the location of an event we try to list a variety of places in our nearby places list. This includes the closest known populated place in relation to the seismic event (which based on our dataset will have a population of 1,000 or greater). We also include the next 3 closest places that have a population of 10,000 or greater, and finally make sure to include the closest capital city to the seismic event.

The reference point for the descriptive locations is usually either the City Hall of the town (or prominent intersection in the middle of town if there is no City Hall), but please refer to the GeoNames website for the most accurate information on their data.

If there is no nearby city within 300 kilometers (or if the nearby cities database is unavailable for some reason), the Flinn-Engdahl (F-E) seismic and geographical regionalization scheme is used. The boundaries of these regions are defined at one-degree intervals and therefore differ from irregular political boundaries. For example, F-E region 545 (Northern Italy) also includes small parts of France, Switzerland, Austria and Slovenia and F-E region 493 (Chesapeake Bay Region) includes all of the State of Delaware, plus parts of the District of Columbia, Maryland, New Jersey, Pennsylvania and Virginia. Beginning with January 2000, the 1995 revision to the F-E code has been used in the QED and PDE listings.

As an agency of the U.S. Government, we are expected to use the names and spellings approved by the U.S. Board on Geographic Names. Any requests to approve additional names should be made to the U.S. Board on Geographic Names.


The magnitude reported is that which the U.S. Geological Survey considers official for this earthquake, and was the best available estimate of the earthquake’s size, at the time that this page was created. Other magnitudes associated with web pages linked from here are those determined at various times following the earthquake with different types of seismic data. Although they are legitimate estimates of magnitude, the U.S. Geological Survey does not consider them to be the preferred "official" magnitude for the event.


Map Projection
The earthquake map projection is Web Mercator.
Map Reference Model
The reference model is WGS-84.
Map Software
Interactive map interface powered by Leaflet.

Map Layers

Grayscale Map

This layer is from an Esri GIS service titled “Light Gray Canvas”. This minimal map is used as the default because it loads more quickly in the browser than the other maps, and it emphasizes the earthquakes. Detailed information about this map is on the Esri website.

Sources: Esri, DeLorme, NAVTEQ.

Terrain Map

This layer is from an Esri GIS service titled “National Geographic World Map”. The map was developed by National Geographic and Esri and reflects the distinctive National Geographic cartographic style in a multi-scale reference map of the world. Detailed information about this map is on the Esri website.

Sources: National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, iPC.

Street Map

Map tiles courtesy MapQuest. Portions of the data courtesy NASA/JPL-Caltech and U.S. Dept. of Agriculture, Farm Service Agency.

Satellite Map

Map tiles courtesy MapQuest. Portions of the data courtesy NASA/JPL-Caltech and U.S. Dept. of Agriculture, Farm Service Agency.

Plate Boundaries

This data was acquired from the Peter Bird Plate Boundary Dataset. NOTE: Included plate boundaries were chosen appropriately based on scale.

U.S. Faults

The data used for these features was acquired from the Hazard Faults Database for the United States. See the Quaternary Fault and Fold Database of the United States for more information.

Known hazardous faults and fault zones in California and Nevada

The known active fault segments in California and Nevada can be seen in Figure 25 of USGS Open-File Report 96-532: National Seismic Hazard Maps, June 1996: Documentation by Arthur Frankel, Charles Mueller, Theodore Barnhard, David Perkins, E.V. Leyendecker, Nancy Dickman, Stanley Hanson, and Margaret Hopper.

For northern California, the potential sources of earthquakes larger than magnitude 6 are documented in Open-File Report 96-705: Database of Potential Sources for Earthquakes Larger than Magnitude 6 in Northern California by the Working Group on Northern California Earthquake Potential (chaired by Jim Lienkaemper).

For the state as a whole, see USGS Open-File Report 96-706: Probabilistic seismic hazard assessment for the State of California by Petersen, M. D., Bryant, W.A., Cramer, C.H., Cao, T., Reichle, M.S., Frankel, A.D., Lienkaemper, J.J., McCrory, P.A., and Schwartz, D.P, 1996 (published jointly as California Division of Mines and Geology Open-File Report 96-08. The faults and fault zones described in these reports are known to have been active in the last 2 million years and are thought to pose a measurable hazard.

For California the faults on the individual zoomed-in and special maps come from the three categories of faults believed to have been active in the last 700,000 years shown on the “Preliminary Fault Activity Map of California” by C.W. Jennings (1992, California Division of Mines and Geology Open-File Report 92-03). This map has been superseded by Jennings, C.W., 1994, Fault activity map of California and adjacent areas, with locations and ages of recent volcanic eruptions: California Division of Mines and Geology, Geologic Data Map No. 6, map scale 1:750,000.

For Nevada the faults on the individual zoomed-in and special maps come from USGS Open-File Report 96-532 mentioned above.

For more information on files and images discussed above visit the 1996 Hazard Maps Documentation Page.

U.S. Hazards

US hazard is from the USGS Seismic Hazard Mapping Project (NSHM)

Realtime Earthquake Data Sources & Contributing Networks

U.S., International, and Offshore Regions


Central and Southeastern U.S.

Cooperative Central and Southeast U.S. Seismic Network CERI/SLU/VPI/USC/…

The participating institutions are:




Lamont-Doherty Cooperative Seismographic Network (LCSN)

The participating institutions are:

Northern California

The participating institutions are:

Pacific Northwest

Pacific Northwest Seismograph Network

The participating institutions are:

Puerto Rico

Southern California

Southern California Seismic Network (SCSN).

The participating institutions are:

Utah and Yellowstone

All members of the …

Network Contacts

National Earthquake Information Center (NEIC)

U.S. Geological Survey
National Earthquake Information Center
Box 25046, DFC, MS 967
Denver, Colorado 80225

Earthquake Information Line: 303-273-8500 (24x7 Operations)
Fax: 303-273-8450
Web Page:

Alaska Earthquake Information Center (AEIC)

Alaska Earthquake Information Center (AEIC)
Geophysical Institute
University of Alaska Fairbanks
903 Koyukuk Drive
Fairbanks, AK 99775-7320

Voice: 907-474-7320
Fax: 907-474-7125
Web Page:

West Coast and Alaska Tsunami Warning Center/NOAA/NWS

West Coast and Alaska Tsunami Warning Center/NOAA/NWS
910 S. Felton St.
Palmer, AK 99645

Web Page:

Cooperative New Madrid Seismic Network

Center for Earthquake Research and Information
Campus Box 526590
The University of Memphis
Memphis, TN 38152

Voice: 901-678-2007
Fax: 901-678-4734
Web Page:

Inter-Mountain West Seismic Networks

Earthquake Studies Office
Montana Bureau of Mines and Geology
1300 West Park Street
Butte, MT 59701-8997

Voice: 406-496-4332
Fax: 406-496-4451
Web Page:

Nevada Seismological Laboratory
University of Nevada, Reno
Reno, Nevada

Voice: 775-784-4975
Fax: 775-784-4165
Web Page:

University of Utah Seismograph Stations
135 South 1460 East
Salt Lake City, Utah 84112-0111

Voice: 801-581-6274
Fax: 801-585-5585
Web Page:

Hawaiian Volcano Observatory Network

U.S. Geological Survey
Hawaiian Volcano Observatory
P O Box 51
Hawaii National Park, Hawaii 96718

Voice: 808-967-7328
Fax: 808-967-8890
Web Page:
Web Page:

Pacific Tsunami Warning Center

U.S. Dept. of Commerce
91-270 Fort Weaver Road
EWA Beach, HI 96706-2928

Voice: 808-689-8207
Web Page:


Lamont-Doherty Cooperative Seismographic Network (LCSN)
Lamont-Doherty Earth Observatory of Columbia University
Palisades, NY 10964

Voice: 845-365-8365
Fax: 845-365-8150
Web Page:

Weston Observatory
Dept. of Geology and Geophysics, Boston College
381 Concord Road Weston, MA 02493-1340

Voice: 617-552-8300
Fax: 617-552-8388
Web Page:

Northern California Seismic Network

U.S. Geological Survey
Seismology Section
345 Middlefield Road - MS 977
Menlo Park, CA 94025

Earthquake Info: 650-329-4025
Voice: 650-329-4085
Fax: 650-329-5163
Web Page: Earthquake Hazards Science Center

U.C. Berkeley Seismological Laboratory
207 McCone Hall
U.C. Berkeley
Berkeley, CA 94720-4760

Earthquake Info: 510-642-2160
Voice: 510-642-3977
Fax: 510-643-5811
Web Page:

Pacific Northwest Seismic Network

University of Washington, Dept. of Earth and Space Sciences
Box 351310
Seattle, WA 98195-1310

Earthquake Info: 206-543-7010
Voice: 206-685-8180 (lab) or 206-543-1190 (department)
Fax: 206-543-0489
Web Page:

Puerto Rico Seismic Network

Puerto Rico Seismic Network
Department of Geology
University of Puerto Rico at Mayagüez
PO Box 9017
Mayagüez, PR 00681-9017

Voice: 787-833-8433
Fax: 787-265-1684
Web Page:

Southern California Seismic Network

Southern California Seismic Network
U.S. Geological Survey - Caltech Seismological Laboratory
Pasadena, California

EQ Info: 626/395-6977
Voice: 626/583-7823 or 626/395-6919
Fax: 626/583-7827
Web Page:
Web Page: