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>.