Seismic Events: Map Layer Description File

This map layer includes a selection of seismic events above 4.0 magnitude in and near the United States for the years 1973-1998. The Seismic Events map layer was compiled by the U.S. Geological Survey from a database maintained by its National Earthquake Information Center.

The magnitude of the earthquake is a logarithmic measure of its "size." This is commonly referred to as the "Richter scale".

• Identification Information
• Data Quality Information
• Spatial Data Organization Information
• Spatial Reference Information
• Entity and Attribute Information
• Distribution Information
• Metadata Reference Information

Identification Information:

Citation:

Citation_Information:

Originator: U.S. Geological Survey (USGS)

Publication_Date: 1996

Title: Earthquakes

Publication_Information:

Publication_Place: Reston, Virginia

Publisher: U.S. Geological Survey

 

Description:

Abstract:

This data set includes a selection of seismic events above 4.0 magnitude in and near the United States for the years 1973-1998.

Purpose:

The digital data sets are used to create electronic and hard copy maps that depict various aspects of the nation. The data can be used to conduct geographic analysis on national and large regional scales. The digital data will provide a basis from which future revisions of the atlas can be derived.

Supplemental_Information:

Revisions: 1) 6/29/98 - Corrected ellipsoid name from WGS84 to GRS1980 and changed flattening ratio.

 

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 1998

Currentness_Reference: publication date

 

Status:

Progress: Complete

Maintenance_and_Update_Frequency: Irregular

 

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: 172.0

East_Bounding_Coordinate: -66.0

North_Bounding_Coordinate: 72.0

South_Bounding_Coordinate: 18.0

 

Keywords:

Theme:

Theme_Keyword_Thesaurus: None

Theme_Keyword: seismic

Theme_Keyword: earthquakes

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 (FIPS) 10-4): Washington, D.C., National Institute of Standards and Technology.

Place_Keyword: United States

 

Access_Constraints: None

Use_Constraints:

None. Acknowledgment of the National Earthquake Information Center (NEIC) would be appreciated in products derived from these data.

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Bruce Wright

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing address

Address: 521 National Center

City: Reston

State_or_Province: VA

Postal_Code: 20192

Contact_Voice_Telephone: 703-648-4528

Contact_Electronic_Mail_Address: bwright@usgs.gov

 

Data Quality Information:

Logical_Consistency_Report:

No tests for logical consistency were performed on this data set.

Completeness_Report:

This data set includes all seismic events in and near the United States. No tests for completeness were performed on this data set.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator:

National Earthquake Information Center (NEIC), USGS-Geologic Division

Publication_Date: 1998

Title: Earthquake data base

Publication_Information:

Publication_Place: Golden, CO

Publisher: USGS

Type_of_Source_Media: online

Source_Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 1973

Ending_Date: 1998

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: n/a

Source_Contribution: spatial and attribute information

Process_Step:

Process_Description:

The data were extracted from the NEIC Earthquake Search WWW site at: <http://wwwneic.cr.usgs.gov/neis/epic/epic.html.> The data were then loaded into an INFO database. Latitude and Longitude values were written to an external file and used as input to the ARC/INFO command GENERATE to create a point coverage. The remaining attributes were joined to the data using the command JOINITEM. A bounding rectangle was used to isolate just those earthquakes located in the area of interest, standard tics were added and point topology was build. A spot check was conducted to validate that the proper attributes were associated with the earthquake locations.

Process_Date: 1998

 

Spatial Data Organization Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Point

Point_and_Vector_Object_Count: 26867

 

Spatial Reference Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.01

Longitude_Resolution: 0.01

Geographic_Coordinate_Units: Decimal Degrees

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: GRS1980

Semi-major_Axis: 6378137

Denominator_of_Flattening_Ratio: 298.257222

 

Entity and Attribute Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: QUAKESX020.PAT

Entity_Type_Definition: Point attribute table

Entity_Type_Definition_Source: ARC/INFO

Attribute:

Attribute_Label: AREA

Attribute_Definition: Point

Attribute_Definition_Source: Computed

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 0.0

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: n/a

Attribute:

Attribute_Label: PERIMETER

Attribute_Definition: Point

Attribute_Definition_Source: Computed

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 0.0

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: n/a

Attribute:

Attribute_Label: QUAKESX020#

Attribute_Definition: Internal feature number

Attribute_Definition_Source: Computed

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Sequential unique positive integer

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: n/a

Attribute:

Attribute_Label: QUAKESX020-ID

Attribute_Definition: User-assigned feature number

Attribute_Definition_Source: User-defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Integer

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: n/a

Attribute:

Attribute_Label: CATALOG_SRC

Attribute_Definition: Contributing source of earthquake data

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value:

PDE = Contributed by USGS NEIC, Preliminary Determination of Epicenters - Monthly Listing

Enumerated_Domain_Value_Definition:

Contributed by USGS NEIC, Preliminary Determination of Epicenters - Monthly Listing

Enumerated_Domain_Value_Definition_Source: NEIC

Attribute:

Attribute_Label: YEAR

Attribute_Definition: Year of the event

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1973-1998

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: NEIC

Attribute:

Attribute_Label: MONTH

Attribute_Definition: Month of the event

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1-12

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: n/a

Attribute:

Attribute_Label: DAY

Attribute_Definition: Day of the event

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1-31

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: n/a

Attribute:

Attribute_Label: ORIGIN_TIME

Attribute_Definition:

Time of the event in Universal Time Coordinated (UTC) in hours, minutes, seconds, and decimal seconds expressed as a single real number.

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 000000.0 - 235959.9

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: n/a

Attribute_Units_of_Measure: decimal degrees

Attribute:

Attribute_Label: LAT

Attribute_Definition: Latitude of earthquake

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 0-90

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: n/a

Attribute_Units_of_Measure: decimal degrees

Attribute:

Attribute_Label: LON

Attribute_Definition: Longitude of earthquake

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: -180 to 0 and 155 to 180

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source: n/a

Attribute:

Attribute_Label: DEPTH

Attribute_Definition: Depth of earthquake in kilometers

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0

Range_Domain_Maximum: 634

Attribute_Units_of_Measure: Kilometers (rounded up to nearest)

Attribute:

Attribute_Label: MAGNITUDE

Attribute_Definition:

Magnitude of the earthquake. It is a logarithmic measure of the "size" of an earthquake. Commonly referred to as the "Richter scale".

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 4.0

Range_Domain_Maximum: 8.10

Attribute:

Attribute_Label: MAG_SCALE

Attribute_Definition: Magnitude scale

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value:

Parameters that apply to the magnitude value. See NEIC WWW site for more information: <http://wwwneic.cr.usgs.gov/neis/epic/code_magnitude.html>

Enumerated_Domain_Value_Definition_Source: NEIC

Attribute:

Attribute_Label: MAG_SOURCE

Attribute_Definition:

Two and three letter acronyms of the source of the magnitude data. See the NEIC WWW site for more information (<http://wwwneic.cr.usgs.gov/neis/epic/code_magnitude.html).>

Attribute_Definition_Source: NEIC

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Various two and three letter acronyms

Enumerated_Domain_Value_Definition: n/a

Enumerated_Domain_Value_Definition_Source:

National Earthquake Information Center

 

Overview_Description:

Entity_and_Attribute_Overview:

The point attribute table:

Column	Item Name	Width	Output	Type	N. Dec.
1	AREA	4	12	F	3
5	PERIMETER	4	12	F	3
9	QUAKESX020#	4	5	B	-
13	QUAKESX020-ID	4	5	B	-
17	CATALOG_SRC	3	3	C	-
20	YEAR	4	4	I	-
24	MONTH	2	2	I	-
26	DAY	2	2	I	-
28	ORIGIN_TIME	4	12	F	2
33	LAT	4	12	F	2
36	LON	4	12	F	2
40	DEPTH	4	4	I	-
44	MAGNITUDE	4	12	F	2
48	MAG_SCALE	2	2	C	-
50	MAG_SOURCE	2	2	C	-

 

Entity_and_Attribute_Detail_Citation: n/a

 

Distribution Information:

Distributor:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Bruce Wright

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing address

Address: 521 National Center

City: Reston

State_or_Province: VA

Postal_Code: 20192

Contact_Voice_Telephone: 703-648-4528

Contact_Electronic_Mail_Address: bwright@usgs.gov

 

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 USGS regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty.

 

Metadata Reference Information:

Metadata_Date: 19980514

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Bruce Wright

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing address

Address: 521 National Center

City: Reston

State_or_Province: VA

Postal_Code: 20192

Contact_Voice_Telephone: 703-648-4528

Contact_Electronic_Mail_Address: bwright@usgs.gov

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: 19940608

Metadata_Security_Information:

Metadata_Security_Classification_System: None

Metadata_Security_Classification: Unclassified

Metadata_Security_Handling_Description: None

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