Earthquake Catalogs
Major Earthquake Catalogs
 NEIC PDE (National Earthquake Information Center
Preliminary Determination of Epicenters)
 Global catalog
 Creates a list of all earthquakes in specific areas
 Global CMT (Global Centroid Moment Tensor)
 Specific earthquake information used to calculate focal
mechanisms
 GNS (Institute of Geologic and Nuclear Science)
 Specific earthquake information in New Zealand
How to Access NEIC PDE Catalog
 Go to http://www.ncedc.org/cnss/
 Click on “Search the catalog”
 Enter dates and/or time into the “Start date, time” and “End
date, time” boxes
 Enter in a magnitude range in the “Min magnitude” and “Max
magnitude” boxes
 Enter latitude and longitude range in the given boxes
 Click “Submit request” button
How to Access the Global CMT
Catalog

Go to http://www.globalcmt.org/

Scroll down to the section that is titled “Links to CMT resources:”

Click on “CMT catalog web search” link

Enter a starting year, month, and day into the “Starting Date:” table

In the “Ending Date:” table select the first row that has year, month, and day

Enter in an ending year, month, and day in the “Ending Date:” table

Under “Magnitude constraints:” type in a range of magnitudes in the two boxes after the title “Moment
Magnitude”

Under “Location constraints:” enter in a range of latitude and longitude in the boxes after the “Latitude:”
and “Longitude:” titles

Select Done
How to Access GNS Catalog
 Go to
http://magma.geonet.org.nz/resources/quakesearch/
 Enter in desired time frame
 Enter in desired latitude and longitude range
 Enter in desired range of magnitude
 Select “Submit”
Uses of Global CMT Catalog
Information
 Use the Global CMT site for focal mechanisms
 The definition of a focal mechanism is: “The direction of slip in an
earthquake and the orientation of the fault on which is occurs” (USGS)
 Input focal mechanisms into SCEC-VDO format by:
 Take information from the CMT search and put it into an excel spreadsheet
 Look up information on longitude, latitude, depth, strike, dip, slip and
magnitude
 The columns on the spreadsheet should be Long, Lat, Depth, Strike, Dip, Slip,
Magnitude (in that order)
 Save the excel spreadsheet as a textfile
Uses of NEIC PDE and GNS
Catalog Information
 NEIC PDE used for global earthquake information
 GNS used for New Zealand earthquake information
 Generate lists of earthquakes in a specific area over a given amount of
time
 Copy the contents of the list of every earthquake
 Paste it into notepad
 Save the notepad document as a textfile
 Import this text file by using the Earthquake Catalog plugin on SCEC-
VDO
Works Cited
 Advanced National Seismic System. “ANSS: Composite
Earthquake Catalog.” 25 July 2011. Web. 23 Sep. 2010.
<http://www.ncedc.org/anss/>.
 Larson, Erik. “Global CMT Catalog Search.” 25 July 2011. Web.
26 Sept 2011.
<http://www.globalcmt.org/CMTsearch.html>.
 GeoNet. Home. 3 Aug 2011. Web. 3 Aug 2011.
<http://www.geonet.org.nz/index.html>.