Earthquake : public <<Feature>> class
Created: 9/25/2007 10:44:56 AM
Modified: 9/25/2007 11:16:39 AM
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<p>This map layer contains the locations and attributes of significant,<br/></p><p>historic earthquakes that caused deaths, property damage, and geological effects, or were otherwise experienced by populations in the United States, Puerto Rico, and U.S. Virgin Islands.  <br/></p><p><br/></p><p>Included are earthquakes<br/></p><p>located in the United States as well as some that occurred in adjacent<br/></p><p>portions of Canada and Mexico.  The main sources for the data are<br/></p><p>Seismicity of the United States, 1568-1989 and the Preliminary<br/></p><p>Determination of Epicenters for 1990 to January 2004.  This is a<br/></p><p>replacement for the June 1999 map layer.<br/></p><p><br/></p><p>These data are intended for geographic display and analysis at the<br/></p><p>national level, and for large regional areas.  The data should be<br/></p><p>displayed and analyzed at scales appropriate for 1:2,000,000-scale data.<br/></p><p>No responsibility is assumed by the National Atlas of the United States<br/></p><p>or the U.S. Geological Survey in the use of these data.  This data set is<br/></p><p>intended for a mixed audience of specialists and non-specialists alike who have a need for general, non-technical information about significant<br/></p><p>United States earthquakes.<br/></p><p><br/></p><p>Provided with the downloadable files is a text file,<br/></p><p>quksigx_references.txt, which contains the reference information for<br/></p><p>earthquake magnitudes listed in the data.<br/></p>
Attribute Details
public DateTime
  EarthquakeWhenDateTime
Notes: When the earthquake occurred.
public LengthMeasure
  EarthquakeDepthKMMeasure
Notes: The depth of earthquake's focus in kilometers.  A value of 0 may indicate the depth is unknown.
public Number
  EarthquakeBodyWaveMagnitudeNumeric
Notes: The body wave magnitude of the earthquake as reported by the U.S.<br />Geological Survey.  A body wave is a seismic wave that travels through the Earth's inner layers.
public Number
  EarthquakeSurfaceWaveMagnitudeNumeric
Notes: The surface wave magnitude of the earthquake as reported by the U.S.<br />Geological Survey.  A surface wave is a seismic wave that travels along the Earth's surface.
public EarthquakeIntensity
  EarthquakeOtherMagnitude
Range:0 to 2
Notes: Other measure of earthquake intensity.
public Number
  EarthquakeMmioNumeric
Notes: Modified Mercalli Intensity (MMI), where the integer value represents<br />the Roman numeral designation of the MMI intensity.
public AreaMeasure
  EarthquakeFeltAreaSqKMAreaMeasure
Notes: The area, in square kilometers, in which the earthquake was felt.
Object Type Connection Notes
«Feature» Hazard Class Generalization  
«Feature» SignificantHistoricalEarthquake Class Generalization