NCEQ7500 - Earthquakes of magnitude 2.5 and greater for the Monterey Bay area

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

Title:

NCEQ7500 - Earthquakes of magnitude 2.5 and greater for the Monterey Bay area

Abstract:

Earthquake data for events of magnitude 2.5 and greater for the Monterey Bay National Marine Sanctuary and adjacent onshore areas. These data were selected from the catalog of the Northern California Earthquake Data Center (NCEDC) for the period 1975 to 2000.

This is one of a collection of digital files of a geographic information system of spatially referenced data related to the USGS Coastal and Marine Geology Program "Monterey Bay National Marine Sanctuary Project" <http://walrus.wr.usgs.gov/mbms>. The data were collected and analyzed between 1994 and 2000.

1. How should this data set be cited?

   Wong, Florence L. , 2001, NCEQ7500 - Earthquakes of magnitude 2.5 and greater for the Monterey Bay area:.

   Online Links:

   • <http://geopubs.wr.usgs.gov/open-file/of01-179>

   This is part of the following larger work.

   Wong, F.L., and Eittreim, S.E., 2001, Continental Shelf GIS for the Monterey Bay National Marine Sanctuary: U.S. Geological Survey Open-File Report 01-179, U.S. Geological Survey, Menlo Park, CA.

   Online Links:

   • <http://geopubs.wr.usgs.gov/open-file/of01-179/>

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -123.23594578

   East_Bounding_Coordinate: -121.47792972

   North_Bounding_Coordinate: 38.00374343

   South_Bounding_Coordinate: 36.54035247

3. What does it look like?

   <http://geopubs.wr.usgs.gov/open-file/of01-179/images/geonceq7500.gif> (GIF)

   location map of nceq7500

4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 1975

   Ending_Date: 2000

   Currentness_Reference: Ground Condition

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: map

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?

      This is a Point data set. It contains the following vector data types (SDTS terminology):

      • Point (2502)

   2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator

      Universal_Transverse_Mercator:

      UTM_Zone_Number: 10

      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.9996

      Longitude_of_Central_Meridian: -123.00000

      Latitude_of_Projection_Origin: 0.00000

      False_Easting: 500000.00

      False_Northing: 0.00

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 16.13355368959
      Ordinates (y-coordinates) are specified to the nearest 16.13355368959
      Planar coordinates are specified in Meters

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is GRS1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257.
      

7. How does the data set describe geographic features?

   Entity_and_Attribute_Overview:

   The earthquake data are recorded as points which are described in the point attribute table NCEQ7500.PAT.

   
   NCEQ7500.PAT: point attribute table
   
   COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
      25  DATE                   8     8     F      0
      33  TIME                   8     9     F      2
      41  LAT                    4     7     F      4
      45  LON                    8     9     F      4
      53  DEPTH_KM               4     5     F      2
      57  MAG                    4     3     F      1
      61  MAGT                   4     4     C      -
      65  NST                    4     3     B      -
      69  GAP                    4     3     B      -
      73  CLO                    4     3     B      -
      77  RMS                    4     4     F      2
      81  SRC                    4     4     C      -
      85  EVENT_ID               8     8     F      0
      93  DATEHHMM               8    12     F      0
   
    DATE        origin date yyyymmdd
    TIME        origin time hhmmss.ss
    LAT         latitude in decimal degrees
    LON         longitude in decimal degrees
    DEPTH_KM    focal depth in kilometers
    MAG         magnitude value
    MAGT        magnitude type: coda, MLm, Mamp
    NST         number of stations used to calculate location
    GAP         azimuthal gap between epicenter and station
    CLO         distance to closest station
    RMS         RMS of residuals in calculation of origin time
    SRC         all from NCSN Northern California Seismic Network
    EVENT_ID    unique sequence number
    DATEHHMM    relate key yyyymmddhhmm
   
   

   Entity_and_Attribute_Detail_Citation:

   <ftp://quake.geo.berkeley.edu/pub/doc/cat5/ncsn.catalog.y2k.5>

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Florence L. Wong

2. Who also contributed to the data set?

3. To whom should users address questions about the data?

   Florence L. Wong
   United States Geological Survey (USGS)
   Geologist, GIS Coordinator
   USGS, MailStop 999, 345 Middlefield Road
   Menlo Park, CA 94025-3561
   USA
   

   (650) 329-5327 (voice)
   (650 329-5190 (FAX)
   fwong@usgs.gov
   

These data are intended for science researchers, students, policy makers, and the general public. The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information about the shallower areas of the Monterey Bay National Marine Sanctuary.

1. From what previous works were the data drawn?

   NCEDC (2000) (source 1 of 1)

   Northern California Earthquake Data Center (NCEDC)., 2000, Northern California Earthquake Catalog: NCEDC, Berkeley, California.

   Type_of_Source_Media: digital files

   Source_Contribution: earthquake records

2. How were the data generated, processed, and modified?

   Date: 2001 (process 1 of 2)

   F.L. Wong selected and downloaded the data from NCEDC and converted the data to a point coverage.

   Date: 13-Feb-2001 (process 2 of 2)

   First draft of metadata created by F.L. Wong using a modified version of FGDCMETA.AML on ARC/INFO data set NCEQ7500

3. What similar or related data should the user be aware of?

1. How well have the observations been checked?

2. How accurate are the geographic locations?

3. How accurate are the heights or depths?

4. Where are the gaps in the data? What is missing?

   Data selected were limited to magnitudes of 2.5 or greater.

5. How consistent are the relationships among the observations, including topology?

   Point features present.

Are there legal restrictions on access or use of the data?

Access_Constraints:

None

Use_Constraints:

Please recognize the U.S. Geological Survey (USGS) as the source of this information.

Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.

The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.

This information is not intended for navigational purposes.

Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

1. Who distributes the data set? (Distributor 1 of 1)

   United States Geological Survey (USGS)
   Geologist, GIS Coordinator
   USGS, MailStop 999, 345 Middlefield Road
   Menlo Park, CA 94025-3561
   USA
   

   (650) 329-5327 (voice)
   (650) 329-5190 (FAX)
   fwong@usgs.gov
   

2. What's the catalog number I need to order this data set?

   USGS Open-File Report 01-179

3. What legal disclaimers am I supposed to read?

   Please recognize the U.S. Geological Survey (USGS) as the source of this information.

   Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.

   Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

   The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	earthquake events with attributes in format ArcInfo Export (.e00) (version 8.0.2) Size: 0.4 megabytes
     Network links:	<http://geopubs.wr.usgs.gov/open-file/of01-179/>

   • Cost to order the data: none

Dates:

Last modified: 13-Feb-2001
Last Reviewed: May-2001

Metadata author:

United States Geological Survey (USGS)
c/o Florence L. Wong
Geologist, GIS Coordinator
USGS, MailStop 999, 345 Middlefield Road
Menlo Park, CA 94025-3561
USA

(650) 329-5327 (voice)
(650) 329-5190 (FAX)
fwong@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata ("CSDGM version 2") (FGDC-STD-001-1998)