Yellowknife Magnetic Observatory

Metadata from the NOAA Metadata Manager's Repository (NMMR)

• Identification_Information
• Data_Quality_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator:Geological Survey of Canada

Publication_Date:1915

Title:

Yellowknife Magnetic Observatory

Online_Linkage:http://www.geolab.nrcan.gc.ca

Description:

Abstract:

During the International Geophysical Year (IGY) an observatory was in operation at Yellowknife A (July, 1957 to August, 1958) on a site about 2 km from the town and on the south side of the airport road. This site is no longer available. The decision was made in 1972 to re-establish a magnetic observatory in Yellowknife, N.W.T. In May, 1973 an area in the vicinity of the Seismology Laboratory was investigated for the location of a new magnetic observatory. The site is approximately 6 km northwest of the IGY observatory and is underlain by Archaean gneissic rocks. Two sites were found which were considered suitable: a 185 m square of land lying between the seismic vault and Long Lake, and a site on the south border of the Seismology Laboratory, 198 m above sea level and 390 m south of Long Lake. The first lot was considered more desirable in that the magnetic sensors could be located at greater distance from potential sources of artificial magnetic disturbance. However, it later transpired that the Government of the Northwest Territories had reserved this land as a recreational area for the town of Yellowknife. Accordingly the magnetic observatory was located on the second site, which was approximately 100 m from the Territorial Government Highways Department lot to the east, the golf course parking lot to the west, and the Mackenzie Highway to the south, and 60 m south of the chainlink fence surrounding the Seismology Laboratory. The average total force gradient measured for the site was 5 nT/m, comparable to that observed previously at the IGY site. To protect the magnetic environment of the observatory, an aluminum fence was built along the boundary with the Highways Department lot and from this boundary west to the fence along the north end of the Seismology Laboratory compound. The building, 6 m by 12 m, was of the same construction as Resolute Bay, Cambridge Bay and Baker Lake observatories. The long axis of the building was oriented geographic east-west. All materials used were non-magnetic. Individual piers were eliminated by the use of a reinforced insulated concrete slab isolated from the walls of the building. By 1986 the site began to experience considerable magnetic interference from heavy road servicing equipment which was occasionally parked in the Department of Highways compound and the from the parking of automobiles for the golf course. As a result, another site was selected which is 170 m west of the new Seismic complex and 100 m south of the Seismic vault. The site is visible from the Geodetic Tripod Bench Mark 39086 which in turn is visible from the Geodetic marker 629102. Accurate geodetic azimuths are then available to the new observatory. The new observatory, approximately 1 km to the northwest of the previous site, consists of two buildings, each 4.8 m by 2.4 m of non-magnetic construction, and various sensor shelters with dimensions as required. Each construct rests on the exposed bedrock which is available on the site. The sensor enclosures are clustered and separated from each other by some 7 m. The instrument cluster is at a distance of 25 m from the Service Building which houses the electrical service panels and the electronic consoles for the instrumentation. The Absolute Building is at a distance of 27 m and on the side of the Service Building opposite to the sensor array. The new Observatory became operational towards the end of June, 1989. A digital recording magnetometer, AMOS MK I, was installed in July, 1974. However, there were a number of problems with the digital equipment and reliable digital data did not become available until October, 1974. The aging AMOS Mk I was replaced by the AMOS Mk III towards the end of March, 1982. In turn the AMOS Mk III was replaced by the INTERMAGNET compliant CANMOS in mid-June, 1991.

Purpose:

To provide ground-based, calibrated values of the Earth's magnetic field at a specific location for scientific research and practical applications.

Supplemental_Information:

Elevation: 198 meters

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date:1915

Ending_Date:Present

Currentness_Reference:

ground condition

Status:

Progress:In work

Maintenance_and_Update_Frequency:Irregular

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate:-114.49

East_Bounding_Coordinate:-114.49

North_Bounding_Coordinate:62.49

South_Bounding_Coordinate:62.49

Keywords:

Theme:

Theme_Keyword_Thesaurus:NASA/GCMD Earth Science Keywords

Theme_Keyword:Earth Science > Solid Earth > Geomagnetism

Theme_Keyword:Earth Science > Solid Earth > Geomagnetism > Geomagnetic Indices

Theme_Keyword:Earth Science > Solid Earth > Geomagnetism > Magnetic Declination

Theme_Keyword:Earth Science > Solid Earth > Geomagnetism > Magnetic Field

Theme_Keyword:Earth Science > Solid Earth > Geomagnetism > Magnetic Inclination

Theme_Keyword:Earth Science > Solid Earth > Geomagnetism > Magnetic Intensity

Theme:

Theme_Keyword_Thesaurus:ISO 19115 Topic Category

Theme_Keyword:geoscientificInformation

Theme_Keyword:intelligenceMilitary

Theme_Keyword:utilitiesCommunication

Theme_Keyword:climatologyMeteorologyAtmosphere

Theme:

Theme_Keyword_Thesaurus:INTERMAGNET

Theme_Keyword:Magnetic Observatory Definitive Data

Access_Constraints:None

Use_Constraints:

None

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:Geological Survey of Canada

Contact_Person:L. McKee

Contact_Address:

Address_Type:mailing

Address:

7-Observatory Crescent

Address:

City:Ottawa

State_or_Province:Ontario

Postal_Code:K1A 0Y3

Country:Canada

Contact_Voice_Telephone:613-837-9158

Contact_Facsimile_Telephone:613-824-9803

Contact_Electronic_Mail_Address:lmckee@NRCan.gc.ca

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Data from the Yellowknife Magnetic Observatory Magnetic Observatory met the requirements for being an INTERMAGNET Magnetic Observatory (IMO), and as such met the specifications listed in the INTERMAGNET Technical Manual (http://www.intermagnet.org//im_manual.pdf)

Quantitative_Attribute_Accuracy_Assessment:

Attribute_Accuracy_Value:Full field

Attribute_Accuracy_Explanation:

Dynamic Range

Quantitative_Attribute_Accuracy_Assessment:

Attribute_Accuracy_Value:0.025 nT

Attribute_Accuracy_Explanation:

Resolution

Quantitative_Attribute_Accuracy_Assessment:

Attribute_Accuracy_Value:8 Hz reduced by a boxcar filter to 1second data; 1 second data reduced to 5 second data

Attribute_Accuracy_Explanation:

Sampling Rate

Quantitative_Attribute_Accuracy_Assessment:

Attribute_Accuracy_Value:9 point Gaussian filter; INTERMAGNET 19 point Gaussian filter for the production of 1 minute data from 5 second data

Attribute_Accuracy_Explanation:

Numeric Filter

Logical_Consistency_Report:

Contact institution

Completeness_Report:

These data represent the complete record set for this station and this time period.

Lineage:

Process_Step:

Process_Description:

Contact institute

Source_Used_Citation_Abbreviation:

Unknown

Process_Date:Unknown

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label:Magnetometer

Entity_Type_Definition:

A scientific instrument for measuring the strength of magnetic fields.

Entity_Type_Definition_Source:

http://en.wikipedia.org/wiki/Magnetometer

Attribute:

Attribute_Label:fluxgate magnetometer

Attribute_Definition:

A kind of magnetometer that detects second harmonic signals from a secondary coil surrounding an iron core that is driven into saturation by a primary coil using radio frequency signals. The second harmonic signal is proportional to the strength of the ambient magnetic field.

Attribute_Definition_Source:

http://www.earthsci.unimelb.edu.au/ES304/MODULES/MAG/NOTES/fluxgate.html

Attribute_Domain_Values:

Unrepresentable_Domain:

This is a type of magnetometer instrument used for measuring the Magnetic Field

Attribute:

Attribute_Label:proton precession magnetometer

Attribute_Definition:

A kind of scalar magnetometer that measures only the strength of the total magnetic field vector and not its direction or components. A hydrogen-rich fluid is polarized using a strong electric current. When the current is turned off, the protons in the fluid precess around the ambient magnetic field at a frequency given by the gyromagnetic ratio and proportional to the strength of the surrounding magnetic field.

Attribute_Definition_Source:

http://en.wikipedia.org/wiki/Magnetometer#Scalar_magnetometers

Attribute_Domain_Values:

Unrepresentable_Domain:

This is a type of magnetometer instrument used for measuring the Magnetic Field

Attribute:

Attribute_Label:Overhauser magnetometer

Attribute_Definition:

A type of scalar magnetometer that employs the precession of free unpaired electrons rather than protons in a fluid.

Attribute_Definition_Source:

http://en.wikipedia.org/wiki/Magnetometer#Scalar_magnetometers

Attribute_Domain_Values:

Unrepresentable_Domain:

This is a type of magnetometer instrument used for measuring the Magnetic Field

Detailed_Description:

Entity_Type:

Entity_Type_Label:Earth's Magnetic Field Components

Entity_Type_Definition:

The Earth's magnetic field is characterized by a direction and intensity which can be determined by various combinations of three of seven possible magnetic field components.

Entity_Type_Definition_Source:

Wienert, K.A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, 1970.

Attribute:

Attribute_Label:Inclination (I)

Attribute_Definition:

The angle which the line of force at a point of observation makes with the horizontal plane, positive when directed downward

Attribute_Definition_Source:

Wienert, K.A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, 1971

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:-90.0

Range_Domain_Maximum:90.0

Attribute_Units_of_Measure:Decimal Degrees or Degrees and Decimal Minutes

Attribute:

Attribute_Label:Declination (D)

Attribute_Definition:

The angle made by the magnetic meridian and the true north meridian, considered positive east of north and negative west of north

Attribute_Definition_Source:

Wienert, K.A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, 1971

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:-180.0

Range_Domain_Maximum:180.0

Attribute_Units_of_Measure:Decimal Degrees or Degrees and Decimal Minutes

Attribute:

Attribute_Label:Horizontal Intensity (H)

Attribute_Definition:

The projection of the geomagnetic field vector on the horizontal plane, always positive

Attribute_Definition_Source:

Wienert, K.A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, 1971

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:0

Range_Domain_Maximum:40000.0

Attribute_Units_of_Measure:nanotesla

Attribute:

Attribute_Label:Vertical Intensity (Z)

Attribute_Definition:

The projection of the geomagnetic field vector on the vertical plane, positive when directed down

Attribute_Definition_Source:

Wienert, K.A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, 1971

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:-70000.0

Range_Domain_Maximum:60000.0

Attribute_Units_of_Measure:nanotesla

Attribute:

Attribute_Label:Total Intensity (F)

Attribute_Definition:

The scalar magnitude of the geomagnetic field vector, always positive

Attribute_Definition_Source:

Wienert, K.A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, 1971

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:25000.0

Range_Domain_Maximum:80000.0

Attribute_Units_of_Measure:nanotesla

Attribute:

Attribute_Label:North Component (X)

Attribute_Definition:

The projection of the horizontal component (H) in the true meridian

Attribute_Definition_Source:

Wienert, K.A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, 1971

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:-10000.0

Range_Domain_Maximum:45000.0

Attribute_Units_of_Measure:nanotesla

Attribute:

Attribute_Label:East Component (Y)

Attribute_Definition:

The projection of the horizontal component on the true east direction, positive when directed eastward

Attribute_Definition_Source:

Wienert, K.A., Notes on geomagnetic observatory and survey practice, UNESCO Earth Sciences 5, 1971

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:-20000.0

Range_Domain_Maximum:20000.0

Attribute_Units_of_Measure:nanotesla

Detailed_Description:

Entity_Type:

Entity_Type_Label:Geographic Location

Entity_Type_Definition:

A coordinate system that provides a means for expressing every location on the Earth using three coordinates of a spherical coordinate system which is aligned with the spin axis of the Earth.

Entity_Type_Definition_Source:

http://en.wikipedia.org/wiki/Geographic_location

Attribute:

Attribute_Label:Latitude

Attribute_Definition:

Latitude is an angular measurement in degrees that gives the location of a place on the Earth above (toward the North pole) or below (toward the South pole) of the equator.

Attribute_Definition_Source:

http://en.wikipedia.org/wiki/Latitude

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:-90

Range_Domain_Maximum:+90

Attribute_Units_of_Measure:angular degrees

Attribute:

Attribute_Label:Longitude

Attribute_Definition:

Longitude is an angluar measurement in degrees that describes the location of a place on the Earth east or west of a north-south line called the Prime Meridian.

Attribute_Definition_Source:

http://en.wikipedia.org/wiki/Longitude

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:-180

Range_Domain_Maximum:+180

Attribute_Units_of_Measure:angular degrees

Attribute:

Attribute_Label:Elevation

Attribute_Definition:

Elevation is the vertical position of a location relative to some height above the Earth's surface, generally taken as the mean sea level or geoid.

Attribute_Definition_Source:

http://en.wikipedia.org/wiki/Geoid

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum:0

Range_Domain_Maximum:unlimited

Attribute_Units_of_Measure:meters

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce

Contact_Person:David Fischman

Contact_Position:Data Manager

Contact_Address:

Address_Type:mailing and physical

Address:

325 Broadway

City:Boulder

State_or_Province:CO

Postal_Code:80303

Country:USA

Contact_Voice_Telephone:303 497-4654

Contact_Facsimile_Telephone:303-497-6513

Contact_Electronic_Mail_Address:david.fischman@noaa.gov

Hours_of_Service:8:00 - 5:00 Mountain

Distribution_Liability:

While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name:IAGA2002

Format_Version_Date:2001

Format_Specification:

http://www.ngdc.noaa.gov/IAGA/vdat/iagaformat.html

Format_Information_Content:

Columnar ASCII values including date, time, and magnetic field values, including header information pertinate to the individual observatory.

File_Decompression_Technique:generally ZIP

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:http://www.ngdc.noaa.gov/IAGA/vdat/iagaformat.html

Digital_Form:

Digital_Transfer_Information:

Format_Name:WDC-A

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:www.wdcb.ru/stp/data/geo_min.val/AIA-Argentine%20Islands/DIGITAL%20WDC%20FORMATS.doc

Access_Instructions:

This is an outdated ASCII format.

Fees:None

Ordering_Instructions:

Contact NGDC for instructions.

Metadata_Reference_Information:

Metadata_Date:

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce

Contact_Person:David Fischman

Contact_Position:Data Manager

Contact_Address:

Address_Type:mailing and physical

Address:

325 Broadway

City:Boulder

State_or_Province:CO

Postal_Code:80303

Country:USA

Contact_Voice_Telephone:303 497-4654

Contact_Facsimile_Telephone:303-497-6513

Contact_Electronic_Mail_Address:david.fischman@noaa.gov

Hours_of_Service:8:00 - 5:00 Mountain

Metadata_Standard_Name:Content Standard for Digital Geospatial Metadata: Extensions for Remote Sensing Metadata

Metadata_Standard_Version:FGDC-STD-012-2002

Metadata_Extensions:

Online_Linkage:http://www.ngdc.noaa.gov/metadata/extensions/local_extensions.html

Profile_Name:NGDC Extensions to FGDC Metadata