Metadata:
  Identification_Information:
    Citation:
      Citation_Information:
        Originator: U.S. Geological Survey
        Publication_Date: 200501
        Title: Significant United States Earthquakes, 1568-2004
        Publication_Information:
          Publication_Place: Reston, VA
          Publisher: National Atlas of the United States
        Online_Linkage: <http://nationalatlas.gov/atlasftp.html?openChapters=chpgeol#chpgeol>

    Description:
      Abstract:
        This map layer contains the locations and attributes of significant,
        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.  Included are earthquakes
        located in the United States as well as some that occurred in adjacent
        portions of Canada and Mexico.  The main sources for the data are
        Seismicity of the United States, 1568-1989 and the Preliminary
        Determination of Epicenters for 1990 to January 2004.  This is a
        replacement for the June 1999 map layer.

      Purpose:
        These data are intended for geographic display and analysis at the
        national level, and for large regional areas.  The data should be
        displayed and analyzed at scales appropriate for 1:2,000,000-scale data.
        No responsibility is assumed by the National Atlas of the United States
        or the U.S. Geological Survey in the use of these data.  This map layer is
        intended for a mixed audience of specialists and non-specialists alike who
        have a need for general, non-technical information about significant
        United States earthquakes.

      Supplemental_Information:
        Provided with the downloadable files is a text file,
        quksigx_references.txt, which contains the reference information for
        earthquake magnitudes listed in the data.

    Time_Period_of_Content:
      Time_Period_Information:
        Range_of_Dates/Times:
          Beginning_Date: 15680101
          Ending_Date: 20040131
      Currentness_Reference: Ground condition

    Status:
      Progress: Complete
      Maintenance_and_Update_Frequency: As needed

    Spatial_Domain:
      Bounding_Coordinates:
        West_Bounding_Coordinate: 143
        East_Bounding_Coordinate: -60
        North_Bounding_Coordinate: 65
        South_Bounding_Coordinate: 10
    Keywords:
      Theme:
        Theme_Keyword_Thesaurus: ISO 19115 Topic Category
        Theme_Keyword: environment
        Theme_Keyword: geoscientificInformation

      Theme:
        Theme_Keyword_Thesaurus: None
        Theme_Keyword: Earthquakes
        Theme_Keyword: Seismic events
        Theme_Keyword: Magnitude
        Theme_Keyword: Body wave magnitude
        Theme_Keyword: Surface wave magnitude
        Theme_Keyword: Modified Mercalli Intensity Scale

      Place:
        Place_Keyword_Thesaurus:
          U.S. Department of Commerce, 1995, Countries, Dependencies, Areas of
          Special Sovereignty, and Their Principal Administrative Divisions
          (Federal Information Processing Standard 10-4): Washington, DC,
          National Institute of Standards and Technology.
        Place_Keyword: United States
        Place_Keyword: Canada
        Place_Keyword: Mexico
      Place:
        Place_Keyword_Thesaurus: None
        Place_Keyword: USA
      Place:
        Place_Keyword_Thesaurus:
          U.S. Department of Commerce, 1987, Codes for the Identification of the
          States, the District of Columbia and the Outlying Areas of The United
          States, and Associated Areas (Federal Processing Standard 5-2):
          Washington, DC, National Institute of Standards and Technology.
        Place_Keyword: Alabama
        Place_Keyword: Alaska
        Place_Keyword: Arizona
        Place_Keyword: Arkansas
        Place_Keyword: California
        Place_Keyword: Colorado
        Place_Keyword: Connecticut
        Place_Keyword: Delaware
        Place_Keyword: District of Columbia
        Place_Keyword: Florida
        Place_Keyword: Georgia
        Place_Keyword: Hawaii
        Place_Keyword: Idaho
        Place_Keyword: Illinois
        Place_Keyword: Indiana
        Place_Keyword: Iowa
        Place_Keyword: Kansas
        Place_Keyword: Kentucky
        Place_Keyword: Louisiana
        Place_Keyword: Maine
        Place_Keyword: Maryland
        Place_Keyword: Massachusetts
        Place_Keyword: Michigan
        Place_Keyword: Minnesota
        Place_Keyword: Mississippi
        Place_Keyword: Missouri
        Place_Keyword: Montana
        Place_Keyword: Nebraska
        Place_Keyword: Nevada
        Place_Keyword: New Hampshire
        Place_Keyword: New Jersey
        Place_Keyword: New Mexico
        Place_Keyword: New York
        Place_Keyword: North Carolina
        Place_Keyword: North Dakota
        Place_Keyword: Ohio
        Place_Keyword: Oklahoma
        Place_Keyword: Oregon
        Place_Keyword: Pennsylvania
        Place_Keyword: Rhode Island
        Place_Keyword: South Carolina
        Place_Keyword: South Dakota
        Place_Keyword: Tennessee
        Place_Keyword: Texas
        Place_Keyword: Utah
        Place_Keyword: Vermont
        Place_Keyword: Virginia
        Place_Keyword: Washington
        Place_Keyword: West Virginia
        Place_Keyword: Wisconsin
        Place_Keyword: Wyoming
        Place_Keyword: Puerto Rico
        Place_Keyword: Virgin Islands
        Place_Keyword: U.S. Virgin Islands
        Place_Keyword: Guam
        Place_Keyword: Northern Mariana Islands

    Access_Constraints: None
    Use_Constraints:
      None.  Acknowledgment of the National Atlas of the United States of America
      and (or) the U.S. Geological Survey would be appreciated in products derived
      from these data.

    Point_of_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Margaret G. Hopper

          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: Mailing address
          Address: MS966, Box 25046, Denver Federal Center
          City: Denver
          State_or_Province: CO
          Postal_Code: 80225-0046
          Country: USA
        Contact_Voice_Telephone: 303-273-8564
        Contact_Facsimile_Telephone: 303-273-8600
        Contact_Electronic_Mail_Address: hopper@usgs.gov

    Data_Set_Credit:
      The following U.S. Geological Survey scientists contributed to this
      map layer: A. Tarr, M. Hopper, J. Dewey, M. McKeever, and N. Trevor.

  Data_Quality_Information:
    Attribute_Accuracy:
      Attribute_Accuracy_Report:
        The attribute table was manually checked for unreasonable attribute values
        for depth and magnitude.
    Logical_Consistency_Report:
      No formal tests for logical consistency were performed on this map layer,
      principally because the map layer contains attribute values that were
      arrived at by either or both quantitative (i.e. instrumental) and
      qualitative (i.e. historical) methods.  Earthquakes that occurred prior to
      the introduction of seismological instrumentation are known only from
      written records, such as newspapers, books and journals, and diaries, which
      often may provide contradictory information that has to be carefully
      examined and weighed.  As seismographs became more common in the early
      1960's, the origin time and location were both more precisely and accurately
      determined but the compilation and evaluation of intensity reports was, and
      still is, a process that involves considerable subjectivity.  As a result,
      all attributes associated with a given earthquake should be considered
      provisional and subject to further revision based on acquisition of new
      information and use of new analytical methods.
    Completeness_Report:
      This map layer contains information on significant, historical earthquakes
      that caused deaths, property damage, geological effects, or that were
      experienced by populations in the epicentral area, for the United States,
      Puerto Rico, the U.S. Virgin Islands, Guam, and the Northern Mariana
      Islands.  These data are limited to the best estimates of earthquake
      locations and to attributes such as magnitude and maximum intensity.

    Positional_Accuracy:
      Horizontal_Positional_Accuracy:
        Horizontal_Positional_Accuracy_Report:
          100 meter is the nominal precision of the reported instrumentally
          located coordinate values but accuracy is considerably less.  Accuracy
          depends upon numerous factors including imprecision of the velocity
          model of the earth, uneven distribution of seismic stations, and
          imprecisions in the computational algorithm.  Following initial
          proofreading of the input data file, a preliminary map of the locations
          of the earthquakes was produced which was examined for gross errors in
          spatial location.
      Vertical_Positional_Accuracy:
        Vertical_Positional_Accuracy_Report:
          Although depths are reported to the nearest 1 kilometer, the accuracy is
          considerably less owing to uncertainties in the velocity model of the
          Earth, uneven distribution of seismic stations, and imprecisions in the
          computational algorithm.

    Lineage:
      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: Stover, Carl W.
            Originator: Coffman, Jerry L.
            Publication_Date: 1993
            Title: Seismicity of the United States, 1568-1989 (Revised)
            Edition: 1
            Online_Linkage: <http://neic.usgs.gov/neis/epic/>
            Series_Information:
              Series_Name: Professional Paper
              Issue_Identification: 1527
            Publication_Information:
              Publication_Place: Washington, DC
              Publisher: U.S. Geological Survey
        Type_of_Source_Media: Paper
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Range_of_Dates/Times:
              Beginning_Date: 1568
              Ending_Date: 1989
          Source_Currentness_Reference: Ground condition
        Source_Citation_Abbreviation: Seismicity of the United States
        Source_Contribution: Principal source of earthquake locations and attributes.

      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: U.S. Geological Survey
            Publication_Date: 200411
            Title: Preliminary Determination of Epicenters (PDE)
            Online_Linkage: <http://neic.usgs.gov/neis/epic/>
        Type_of_Source_Media: Online
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Range_of_Dates/Times:
              Beginning_Date: 1973
              Ending_Date: 20040131
          Source_Currentness_Reference: Ground condition
        Source_Citation_Abbreviation: PDE
        Source_Contribution: Supplemental source of earthquake locations and attributes.

      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: J.L. Coffman (ed.)
            Originator: C.A. von Hake (ed.)
            Originator: C.W. Stover (ed.)
            Publication_Date: 1982
            Title: Earthquake History of the United States
            Publication_Information:
              Publication_Place: Boulder, CO
              Publisher:
                National Oceanic and Atmospheric Administration and U.S.
                Geological Survey
        Type_of_Source_Media: Paper
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Range_of_Dates/Times:
              Beginning_Date: 1638
              Ending_Date: 1980
          Source_Currentness_Reference: Ground condition
        Source_Citation_Abbreviation: EHUS1982
        Source_Contribution: Supplemental source of earthquake locations and attributes.

      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: J.G. Tanner
            Originator: J.B. Shepherd
            Publication_Date: 1997
            Title:
              Project catalogue and seismic hazard maps, Seismic hazard in Latin
              America and the Caribbean
            Online_Linkage: <http://midas.uprm.edu>
        Type_of_Source_Media: Online
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Single_Date/Time:
              Calendar_Date: 1997
          Source_Currentness_Reference: Publication date
        Source_Citation_Abbreviation: MIDAS-IPGH
        Source_Contribution: Supplemental source of earthquake locations and attributes.

      Process_Step:
        Process_Description:
          Data for the years 1568 to 1989, from Seismicity of the United States,
          were combined with Preliminary Determination of Epicenters data for 1990
          to 2004.  EHUS1982 and MIDAS-IPGH were used to compile information for
          additional locations or for years not covered by the other sources.  The
          resulting text file was loaded into ArcView and converted to a
          shapefile.  Three records for Puerto Rico were dropped because they did
          not include values for longitude and latitude.
        Source_Used_Citation_Abbreviation: Seismicity of the United States
        Source_Used_Citation_Abbreviation: PDE
        Source_Used_Citation_Abbreviation: EHUS1982
        Source_Used_Citation_Abbreviation: MIDAS-IPGH
        Process_Date: 200411

  Spatial_Data_Organization_Information:
    Indirect_Spatial_Reference:
      U.S. Department of Commerce, 1987, Codes for the Identification of the
      States, the District of Columbia and the Outlying Areas of The United
      States, and Associated Areas (Federal Information Processing Standard 5-2):
      Washington, DC, National Institute of Standards and Technology.

    Direct_Spatial_Reference_Method: Point
    Point_and_Vector_Object_Information:
      SDTS_Terms_Description:
        SDTS_Point_and_Vector_Object_Type: Point
        Point_and_Vector_Object_Count: 5351

  Spatial_Reference_Information:
    Horizontal_Coordinate_System_Definition:
      Geographic:
        Latitude_Resolution: 0.000278
        Longitude_Resolution: 0.000278
        Geographic_Coordinate_Units: Decimal degrees
      Geodetic_Model:
        Horizontal_Datum_Name: North American Datum of 1983
        Ellipsoid_Name: GRS1980
        Semi-major_Axis: 6378137.0
        Denominator_of_Flattening_Ratio: 298.257222

  Entity_and_Attribute_Information:
    Detailed_Description:
      Entity_Type:
        Entity_Type_Label: Significant United States Earthquakes (described by Quksigx020.dbf)
        Entity_Type_Definition:
          Earthquakes within or near to the United States that caused deaths,
          property damage, or geological effects, or that were experienced by
          populations in the epicentral area.  These events occurred between 1568
          and January 2004.
        Entity_Type_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Shape
        Attribute_Definition: The representation of the entity in the data.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: Point
            Enumerated_Domain_Value_Definition: 0-dimensional element
            Enumerated_Domain_Value_Definition_Source: ESRI GIS software
      Attribute:
        Attribute_Label: Quksigx020
        Attribute_Definition: Internal feature number.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 1
            Range_Domain_Maximum: 5387
      Attribute:
        Attribute_Label: Quake_id
        Attribute_Definition: Internal feature number.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 1
            Range_Domain_Maximum: 5390
      Attribute:
        Attribute_Label: Year
        Attribute_Definition: The year when the earthquake occurred.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 1568
            Range_Domain_Maximum: 2004
      Attribute:
        Attribute_Label: Month
        Attribute_Definition: The month when the earthquake occurred.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 1
            Range_Domain_Maximum: 12
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999
            Enumerated_Domain_Value_Definition: The month of the event is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Day
        Attribute_Definition: The day when the earthquake occurred.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 1
            Range_Domain_Maximum: 31
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999
            Enumerated_Domain_Value_Definition: The day of the event is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Hour
        Attribute_Definition:
          The GMT hour of the day when the earthquake occurred, on a 24-hour
          clock.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 0
            Range_Domain_Maximum: 23
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999
            Enumerated_Domain_Value_Definition: The hour of the event is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Minute
        Attribute_Definition: The minute of the hour when the earthquake occurred.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 0
            Range_Domain_Maximum: 59
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999
            Enumerated_Domain_Value_Definition: The minute of the event is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Second
        Attribute_Definition: The second of the minute when the earthquake occurred.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 0.010
            Range_Domain_Maximum: 59.970
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999.000
            Enumerated_Domain_Value_Definition: The second of the event is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Location
        Attribute_Definition:
          The name of the town, city, physical feature, or other describable
          location near to the earthquake event.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Unrepresentable_Domain: There is no predefined set of valid location names.
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: <Blank>
            Enumerated_Domain_Value_Definition: No location description is available.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Longitude
        Attribute_Definition: The longitude of earthquake's epicenter in decimal degrees.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: -179.990
            Range_Domain_Maximum: 180.000
      Attribute:
        Attribute_Label: Latitude
        Attribute_Definition: The latitude of earthquake's epicenter in decimal degrees.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 12.686
            Range_Domain_Maximum: 68.689
      Attribute:
        Attribute_Label: Depth_km
        Attribute_Definition:
          The depth of earthquake's focus in kilometers.  A value of 0 may
          indicate the depth is unknown.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 0
            Range_Domain_Maximum: 274
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999
            Enumerated_Domain_Value_Definition: The depth is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Mb_gs
        Attribute_Definition:
          The body wave magnitude of the earthquake as reported by the U.S.
          Geological Survey.  A body wave is a seismic wave that travels through
          the Earth's inner layers.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 3.400
            Range_Domain_Maximum: 7.000
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999.000
            Enumerated_Domain_Value_Definition: The body wave magnitude is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Ms_gs
        Attribute_Definition:
          The surface wave magnitude of the earthquake as reported by the U.S.
          Geological Survey.  A surface wave is a seismic wave that travels along
          the Earth's surface.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 3.100
            Range_Domain_Maximum: 8.500
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999.000
            Enumerated_Domain_Value_Definition: The surface wave magnitude is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Other_mag1
        Attribute_Definition:
          The magnitude of the earthquake as reported by the source identified in
          Ref1.  The type of magnitude is described by the attribute Type1.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 2.080
            Range_Domain_Maximum: 9.240
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999.000
            Enumerated_Domain_Value_Definition: No additional magnitude measurement is available.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Type1
        Attribute_Definition:
          The type of magnitude recorded in the attribute Other_mag1, as defined
          by the source identified in Ref1.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: FA
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag1 is an estimated body wave
              magnitude.  It is commonly computed from the felt area for
              earthquakes which occurred before seismic instruments were in
              general use.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: MD
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag1 is based on the duration or coda
              length of the earthquake vibration.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: ML
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag1 is the local magnitude, which is
              also known as the original "Richter" magnitude.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: MW
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag1 is the moment magnitude.  It is
              the measure of total energy released by an earthquake.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: Mn
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag1 is the local or regional
              magnitude.  It is the body wave magnitude using the Lg wave.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: Ms
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag1 is the surface wave magnitude.  A
              surface wave is a seismic wave that travels along the Earth's
              surface.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: Mw
            Enumerated_Domain_Value_Definition: The magnitude given in Other_mag1 is the moment magnitude.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: UK
            Enumerated_Domain_Value_Definition: The magnitude type for the magnitude given in Other_mag1 is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: mb
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag1 is the body wave magnitude.  A
              body wave is a seismic wave that travels through the Earth's inner
              layers.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: mbLg
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag1 is the local or regional
              magnitude.  It is the body wave magnitude using the Lg wave.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: <Blank>
            Enumerated_Domain_Value_Definition:
              The type of magnitude given in Other_mag1 is unknown.  The value
              came from Coffman, Jerry L., and von Hake, Carl A., 1973,
              Earthquake History of the United States:  U.S. Dept. of Commerce,
              National Oceanic and Atmospheric Administration, Publication 41-1,
              Revised Edition (Through 1970).
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Ref1
        Attribute_Definition:
          A code identifying the source for the magnitude given in Other_mag1.
          The list of sources is provided in the text file quksigx_references.txt.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Unrepresentable_Domain: There is no predefined set of valid reference codes.
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: <Blank>
            Enumerated_Domain_Value_Definition: No reference information is available.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States

      Attribute:
        Attribute_Label: Other_mag2
        Attribute_Definition:
          The magnitude of the earthquake as reported by the source identified in
          Ref2.  The type of magnitude is described by the attribute Type2.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 2.900
            Range_Domain_Maximum: 8.400
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: -9999.000
            Enumerated_Domain_Value_Definition: No additional magnitude measurement is available.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Type2
        Attribute_Definition:
          The type of magnitude recorded in the attribute Other_mag2, as defined
          by the source identified in Ref2.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: FA
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag2 is an estimated body wave
              magnitude.  It is commonly computed from the felt area for
              earthquakes which occurred before seismic instruments were in
              general use.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: MD
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag2 is based on the duration or coda
              length of the earthquake vibration.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: ME
            Enumerated_Domain_Value_Definition:

              The magnitude given in Other_mag2 is the energy magnitude which is
              the radiated energy of the earthquake.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: ML
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag2 is the local magnitude, which is
              also known as the original "Richter" magnitude.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: MW
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag2 is the moment magnitude.  It is
              the measure of total energy released by an earthquake.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: Mn
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag2 is the local or regional
              magnitude.  It is the body wave magnitude using the Lg wave.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: Ms
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag2 is the surface wave magnitude.  A
              surface wave is a seismic wave that travels along the Earth's
              surface.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: Mw
            Enumerated_Domain_Value_Definition: The magnitude given in Other_mag2 is the moment magnitude.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: UK
            Enumerated_Domain_Value_Definition: The magnitude type for the magnitude given in Other_mag2 is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: mb
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag2 is the body wave magnitude. A body
              wave is a seismic wave that travels through the Earth's inner
              layers.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: mbLg
            Enumerated_Domain_Value_Definition:
              The magnitude given in Other_mag2 is the local or regional
              magnitude.  It is the body wave magnitude using the Lg wave.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: <Blank>
            Enumerated_Domain_Value_Definition:
              The type of magnitude given in Other_mag2 is unknown.  The value
              came from Coffman, Jerry L., and von Hake, Carl A., 1973,
              Earthquake History of the United States:  U.S. Dept. of Commerce,
              National Oceanic and Atmospheric Administration, Publication 41-1,
              Revised Edition (Through 1970).
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Ref2
        Attribute_Definition:
          A code identifying the source for the magnitude given in Other_mag2.
          The list of sources is provided in the text file quksigx_references.txt.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Unrepresentable_Domain: There is no predefined set of valid references.
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: <Blank>
            Enumerated_Domain_Value_Definition: No reference information is available
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Mmio
        Attribute_Definition:
          Modified Mercalli Intensity (MMI), where the integer value represents
          the Roman numeral designation of the MMI intensity.
        Attribute_Definition_Source: U.S. Geological Survey
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: F
            Enumerated_Domain_Value_Definition:
              The earthquake was felt but no Modified Mercalli Intensity was
              assigned.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 2
            Enumerated_Domain_Value_Definition:
              An earthquake felt only by a few persons at rest, especially on
              upper floors of buildings.  Delicately suspended objects may swing.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 3
            Enumerated_Domain_Value_Definition:
              An earthquake felt quite noticeably by persons indoors, especially
              on upper floors of buildings.  Many people do not recognize it as an
              earthquake.  Standing motor cars may rock slightly.  Vibration
              similar to the passing of a truck.  Duration estimated in some
              cases.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 4
            Enumerated_Domain_Value_Definition:
              An earthquake felt indoors by many, outdoors by few during the day.
              At night, some awakened.  Dishes, windows, doors disturbed; walls
              make cracking sound.  Sensation like heavy truck striking building.
              Standing motor cars rocked noticeably.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 5
            Enumerated_Domain_Value_Definition:
              An earthquake felt by nearly everyone; many awakened.  Some dishes,
              windows broken.  Unstable objects overturned.  Pendulum clocks may
              stop.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 6
            Enumerated_Domain_Value_Definition:
              An earthquake felt by all; many frightened.  Some heavy furniture
              moved; a few instances of fallen plaster.  Damage slight.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 7
            Enumerated_Domain_Value_Definition:
              An earthquake causing negligible damage in buildings of good design
              and construction; slight to moderate in well-built ordinary
              structures; considerable damage in poorly built or badly designed
              structures; some chimneys broken.  Noticed by persons driving motor
              cars.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 8
            Enumerated_Domain_Value_Definition:
              An earthquake causing slight damage in specially designed
              structures; considerable in ordinary substantial buildings with
              partial collapse.  Damage great in poorly built structures.  Fall of
              chimneys, factory stacks, columns, monuments, walls.  Heavy
              furniture overturned.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 9
            Enumerated_Domain_Value_Definition:
              An earthquake causing considerable damage in specially designed
              structures; well-designed frame structures thrown out of plumb.
              Damage great in substantial buildings, with partial collapse.
              Buildings shifted off foundations.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 10
            Enumerated_Domain_Value_Definition:
              An earthquaking causing destruction of some well-built wooden
              structures; most masonry and frame structures destroyed with
              foundations.  Railroad rails bent.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 11
            Enumerated_Domain_Value_Definition:
              An earthquake where few, if any (masonry) structures remain
              standing.  Bridges destroyed.  Railroad rails bent greatly.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 12
            Enumerated_Domain_Value_Definition:
              An earthquake where damage is total.  Lines of sight and level
              distorted.  Objects thrown into the air.
            Enumerated_Domain_Value_Definition_Source: <http://neic.usgs.gov/neis/epic/mm_scale.html>
      Attribute:
        Attribute_Label: Felt_area
        Attribute_Definition: The area, in square kilometers, in which the earthquake was felt.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: <1,000
            Range_Domain_Maximum: 5,000,000
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: <Blank>
            Enumerated_Domain_Value_Definition: The area in which the earthquake was felt is unknown.
            Enumerated_Domain_Value_Definition_Source: National Atlas of the United States
      Attribute:
        Attribute_Label: Source
        Attribute_Definition: The primary source of the earthquake information.
        Attribute_Definition_Source: National Atlas of the United States
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: EHUS1982
            Enumerated_Domain_Value_Definition:
              Coffman, J.L., von Hake, C.A., and Stover, C.W., 1982, Earthquake
              History of the United States:  U.S. National Oceanic and Atmospheric
              Administration and U.S. Geological Survey, Publication No. 41-1,
              revised edition, [through 1980], 258p.
            Enumerated_Domain_Value_Definition_Source: U.S. Geological Survey
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: MIDAS-IPGH
            Enumerated_Domain_Value_Definition:
              Tanner, J.G. and Shepherd, J.B., 1997, Project catalogue and seismic
              hazard maps, Seismic hazard in Latin America and the Caribbean:
              Panamerican Institute of Geography and History, v. 1, 143 p.
            Enumerated_Domain_Value_Definition_Source: U.S. Geological Survey
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: PDE
            Enumerated_Domain_Value_Definition:
              Preliminary Determination of Epicenters, a list of earthquakes
              located by the National Earthquake Information Center of the U.S.
              Geological Survey and its predecessors in the U.S. Coast and
              Geodetic Survey, the National Oceanic Survey, and the Environmental
              Research Laboratories of the Department of Commerce.  The PDE is
              comprised of final hypocenter and magnitude computations by the USGS
              NEIC published in monthly lists several months after the events.
            Enumerated_Domain_Value_Definition_Source: U.S. Geological Survey
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: SUS
            Enumerated_Domain_Value_Definition:
              Stover, Carl W., and Coffman, Jerry L., 1993a, Seismicity of the
              United States, 1568-1989 (Revised):  U.S. Geological Survey
              Professional Paper 1527, 418 p.
            Enumerated_Domain_Value_Definition_Source: U.S. Geological Survey
  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Organization_Primary:
          Contact_Organization: Earth Science Information Center, U.S. Geological Survey
        Contact_Address:
          Address_Type: Mailing address
          Address: 507 National Center
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
        Contact_Voice_Telephone: 1-888-ASK-USGS (1-888-275-8747)
        Contact_Voice_Telephone: 703-648-5920
        Contact_Instructions:
          In addition to the address above there are other ESIC offices throughout
          the country.  A full list of these offices is at
          <http://ask.usgs.gov/esic_index.html>.

    Distribution_Liability:
      Although these data have been processed successfully on a computer system at
      the U.S. Geological Survey, no warranty expressed or implied is made by the
      U.S. Geological Survey regarding the utility of the data on any other
      system, nor shall the act of distribution constitute any such warranty.  No
      responsibility is assumed by the U.S. Geological Survey in the use of these
      data.

    Standard_Order_Process:
      Digital_Form:
        Digital_Transfer_Information:
          Format_Name: ESRI Shapefile
        Digital_Transfer_Option:
          Online_Option:
            Computer_Contact_Information:
              Network_Address:
                Network_Resource_Name: <http://nationalatlas.gov/atlasftp.html?openChapters=chpgeol#chpgeol>
      Digital_Form:
        Digital_Transfer_Information:
          Format_Name: SDTS
        Digital_Transfer_Option:
          Online_Option:
            Computer_Contact_Information:
              Network_Address:
                Network_Resource_Name: <http://nationalatlas.gov/atlasftp.html?openChapters=chpgeol#chpgeol>
      Fees: There is no charge for the map layer.

  Metadata_Reference_Information:
    Metadata_Date: 20060620
    Metadata_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Gita Urban-Mathieux
          Contact_Organization: National Atlas of the United States
        Contact_Address:
          Address_Type: Mailing address
          Address: 12201 Sunrise Valley Dr
          Address: MS 561
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
        Contact_Voice_Telephone: 703-648-5175
        Contact_Electronic_Mail_Address: atlasmail@usgs.gov
    Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
    Metadata_Standard_Version: FGDC-STD-001-1998
    Metadata_Security_Information:
      Metadata_Security_Classification_System: None
      Metadata_Security_Classification: Unclassified
      Metadata_Security_Handling_Description: None