Earthquakes: Identification Information
Originator: National Earthquake Information Center World Data Center
Title: National Earthquake Information Center World Data Center for Seismology,
Abstract: USGS/NEIC, 1973- March 2003:
(PDE) Preliminary Determinations of Epicenters, Monthly Listing. 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 Internation Seismological Centre (ISC), which is produced about two years after the earthquakes occur. The NEIC PDE program contributes about one-third off all data used by the ISC.
This catalog is a listing of earthquakes, 2150 B.C. - 1991 (Paula K. Dunbar, Patricia A. Lockridge, and Lowell S. Whiteside, September 1992) supplemented by post-1991 data from the USGS/NEIC. The list includes all events that meet at least one of the following criteria:
1. Moderate damage (approximately $1 million or more)
2. Ten or more deaths
3. Magnitude 7.5 or greater
4. Intensity X or greaterbr> The events occurring prior to 1900 were assigned an epicenter based on the locations where damage occurred. Magnitudes are stated as Ms (Surface Wave) or the equivalent derived from intensities for pre-instrumental events.
Access Constraints: none
Use Constraints: It is ultimately the user's responsibility to assess the accuracy and completeness of a data-set extracted
from the data base and to determine if these are sufficient for the purposes to which the data-set would be applied.
Ordering Instructions: full dataset available online, see online linkage below
Contact Person: Madeleine Zirbes
Contact Organization: U.S. Geological Survey; National Earthquake Information Center
State or Province: Colorado
Online Linkage: http://wwwneic.cr.usgs.gov/neis/epic/database.html
Entity and Attribute Information (table heading explanations)
Shape: ArcView file type (quakes_pde1973_mar2003.shp, quakes_significant_noaa .shp)
Source: Contributing source, or authority:
PDE: Preliminary Determinations of Epicenters, Monthly Listing
Mo: Month earthquake occurred
Da: Day earthquake occurred
Orig_time: (Orig Time in Screen Format) Given in Coordinated Universal Time (UTC)
Dep: Depth: value given in kilometers
Mag: Magnitude, a logarithmic measure of the “size” of an earthquake, is related to the
energy released as seismic waves at the focus of an earthquake.
Global GIS Note: Although the Global GIS interface shows earthquakes above magnitude 4, lower magnitudes exist in the file. To change the legend, please see the Arc View tutorial in the help section or use the Earthquake Tools in the interface to change legends. This will allow one to draw all earthquakes in this database.