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MARC PROPOSAL NO. 2006-06

DATE: May 31, 2006
REVISED: June 20, 2006

NAME: Definition of field 034 for geographic coordinates in the MARC 21 Authority Format

SOURCE: George A. Smathers Libraries (University of Florida) and ALA/MAGERT Cataloging and Classification Committee

SUMMARY: This paper proposes the addition of field 034 to authority records for geographic coordinates associated with places. This field would eventually form the basis for coordinates-based retrieval of all cataloged records containing those geographic terms.

KEYWORDS: Field 034 (AD); Coded Cartographic Mathematical Data (AD); Geographic Coordinates (AD), GIS (AD)

RELATED: : 2006-DP01 (January 2006)

STATUS/COMMENTS:

05/31/06 - Made available to the MARC 21 community for discussion.

06/24/06 - Results of the MARC Advisory Committee discussion - Approved as amended. Subfield codes $r (Distance from earth), $x (Beginning date), $y (Ending date), $z (Name of extraterrestrial body) and $2 (Source) will be added to field 034 in the bibliographic format.

10/12/06 - Results of LC/LAC/BL review - Approved


Proposal No.: 2006-06: Recording geographic coordinates

1. BACKGROUND

Geographic Information Systems (GIS) have become widely available as a mechanism for understanding various types of information through a geographic view. They have become an attractive technology that most proponents claim has revolutionized the way we look at the world and the way we can solve the issues of switching from print to digitization technology.

To solve problems using GIS, you must have information or data geo-referenced that can be layered with more data. Libraries are a significant source of such information, and the effectiveness with which libraries supply that information can do much to aid or hinder those attempting to solve problems using GIS. Spatial analysis can allow for geographical searches of library materials. Digital libraries provide an opportunity to incorporate rich searching by geographic location, returning various relevant material, including, for example, maps, images, reports, or photographs that are identified with a particular location. In academic library settings patrons from a variety of fields are coming together in their usage of GIS as a tool and in their need for the library to supply better access to information relevant to these many fields. Information in library catalogs need to be able to interact with geographic information systems to provide enhanced access to library materials.

In library catalog records for maps and other cartographic materials, a pair of MARC fields, field 034 (Coded Cartographic Mathematical Data) and field 255 (Cartographic Mathematical Data), have long been used to unambiguously identify the location of a coverage area with geographic coordinates. In recent years online catalogs of some libraries have become able to use this data as a retrieval point for patrons. Generally these fields have seen very limited use in that they have been used only when the coordinates actually appear on the cartographic item being cataloged and never on other forms of materials other than maps which may have significant value for layering of GIS data.

At its Jan. 2006 ALA Midwinter meeting, the MARC Advisory Committee considered Discussion Paper No. 2006-DP01, which explored issues concerning the possible definition of a field for cartographic data in the MARC 21 authority record. Participants agreed that a proposal to define field 034 (Coded Cartographic Mathematical Data) should be presented at the next meeting. Consensus was that the proposal should include the following features:

2. DISCUSSION

2.1 Coordinates in Authority Records

In authority records for places, geographic coordinates have frequently been included in note fields (field 670) cited from authoritative sources to document the place name. However, because the data is recorded in a textual form and is not isolated, it would be difficult to utilize the information for a coordinates-based search in the context of the note. Repetition of the coordinates in a specific data field amenable to machine retrieval and compatible with other geographic database searching systems would offer the potential for patrons to better retrieve items concerning a subject place. Another advantage to recording coordinates in authority records is that enhances their value as authoritative resources both within and outside the library community. As such it increases the value of the authority file, since coordinates are a universal language.

It would be appropriate to include coordinates in authority records, because it is important information about the entity described in the authority record. Since this is information about the place for which the authority record is made, it belongs in the authority record, rather than in every bibliographic record that relates to that place. To use the geographic data, systems would need to be programmed to utilize such information by linking between bibliographic and authority records.

In the context of the bibliographic record these subfields record the specific coordinates given on the map or other geospatial resource; in the authority format the coordinates apply to the entity described and would be taken from a reliable source such as the USGS Geographic Names Information System (GNIS) record for the place or from a gazetteer.

In bibliographic records, coordinates appear in textual form in subfield $c of the field 255 and in structured form in field 034. The data in field 034 may be given either as decimal degrees, or as degrees, minutes and seconds with the presence of the decimal indicating which is used. The west, east, north and south hemispheres are indicated either with the first letter of the direction or by plus or minus. This paper proposes only the definition of field 034 and not the textual form in field 255 in the MARC 21 authority record, because the structured form is needed to utilize the data for coordinates-based machine retrieval.

2.2 Field 034 in Authority Format.

Types of authority records that may benefit from the addition of coordinate data are records for place names, geographic features, and some subject headings such as battles, buildings, etc. It is clear that addition of this data in authority records would be a major undertaking, and it would need to be a cooperative project between the library and geospatial communities. It may be possible to extract the data from reliable sources.

2.2.1. Data elements needed from bibliographic field 034. Field 034 should be defined in the authority format as a repeatable field and the data recorded derived from authoritative sources, e.g. the U.S. Board on Geographic Names, which often gives lists of coordinates for places. Only those data elements relevant to the entity described in the authority record should be defined, as opposed to the manifestation described in the bibliographic record.

The current definition of bibliographic field 034 is as follows:

034 Coded Cartographic Mathematical Data (R)

   Indicators
      First - Type of scale
         0 - Scale indeterminable/No scale recorded
         1 - Single scale
         3 - Range of scales
      Second - Type of ring
         # - Not applicable
         0 - Outer ring
         1 - Exclusion ring
   Subfield Codes
      $a - Category of scale (NR)
         a - Linear scale 
         b - Angular scale
         z - Other type of scale
      $b - Constant ratio linear horizontal scale (R)
      $c - Constant ratio linear vertical scale (R)
      $d - Coordinates--westernmost longitude (NR)
      $e - Coordinates--easternmost longitude (NR)
      $f - Coordinates--northernmost latitude (NR)
      $g - Coordinates--southernmost latitude (NR)
      $h - Angular scale (R)
      $j - Declination--northern limit (NR)
      $k - Declination--southern limit (NR)
      $m - Right ascension--eastern limit (NR)
      $n - Right ascension--western limit (NR)
      $p - Equinox (NR)
      $s - G-ring latitude (R)
      $t - G-ring longitude (R)
      $6 - Linkage (NR)
      $8 - Field link and sequence number (R)


The first indicator and subfields $a, $b, $c, and $h are not applicable because they relate to scale of a particular map, not the entity itself that the authority record describes, so would not be defined. The key data elements for recording coordinates are subfield $d, $e, $f and $g. For stars there are standard lines in the sky similar to coordinates that are recorded in subfields $j-$n in field 034. Subfields $s and $t for G-rings may also be applicable, so should be retained.

2.2.2. Associating coordinate data with dates. In order to allow for entities whose coordinates change over time (e.g. changing boundaries for political entities), it is necessary to include date information in the authority record associated with the coordinates. The following options may be considered:

For Option 2, a method would need to be provided to link to the appropriate field 034 in the case of repeated fields. In addition, indicators specify whether there are multiple dates or not, adding to the complexity of processing the data. Thus, option 1 seems the more practical option and is the only one considered in this proposal.

The following subfields could be defined in authority field 034:

$x Beginning date
$y Ending date

Instructions for the use of the field would specify using the YYYYMMDD structured form. If a B.C.E. date is needed, additional conventions will need to be determined, such as those used in field 045.

It may be necessary to record in the record the date when the information was found. This might be recorded in the information in field 670 (Sources found). In cases where no dates are recorded in the field, it is assumed that the coordinates information is current.

2.2.3. Coordinate data for celestial bodies. The MARC Advisory Committee discussion of 2006-DP01 indicated the need for recording coordinates for celestial bodies, such as planets or stars. In addition to the coordinates, to understand their location these types of bodies need a subfield for distance from the earth, which is needed to locate objects in space. For stars there are standard lines in the sky called declination and right ascension that are similar to the equator and Greenwich Mean in that they enable users to point to a spot or an area in the sky as seen from the Earth. Those are the subfields $j-n in field 034. However, although we can assume that a place on the Earth or a planet is on its surface, stars need another data subfield or third dimension to define their location in space. Astronomers use the distance from the Earth in light-years in star atlases as that data. This proposal suggests subfield $r for Distance from earth.

In addition for extraterrestrial bodies the name of the planet is needed, since the coordinate information is unique only in relation to the particular body. This is necessary to enable machine discrimination between the exact same coordinates that might be used for different places on different bodies. With Earth as a default, the existence of a planet-name subfield in a record will at least indicate when Earth is not the location of the feature in question. The assumption is that the coordinate data is for an entity on the earth unless the name of a planet or other extraterrestrial body is specified; subfield $z is proposed for Name of planet.

2.2.4. Indicating source of data in the field. Since there might be varying sources for coordinate data, it is important to indicate the source of the particular data in the field. However, field 670 (Sources found) cites sources used in the creation of the authority record, with direct references given as parenthetical information. Since field 670 is in a textual format and the data is not parsed, it would be difficult to use for machine processing. An authority field 034 would probably rely on machine processing, since it is likely to be added to the record and possibly updated programmatically. Thus, a separate subfield associated with the coordinate data is preferable to indicate source of the data in that particular field; whether to repeat the information in field 670 is a matter of policy and practice. Subfield $2 could be defined for source of data and a source code list developed for use in this field and made available in the MARC 21 Code List for Relators, Sources, Description Conventions. The field would be repeated if there were different sources, since the information in different subfields could come from different sources, and it would not be clear. For instance, a given source may have included coordinate data, while another source may have included dates applicable, and it would be ambiguous which data came from which source if the subfield were simply repeated. Thus, subfield $2 is proposed as non-repeatable. Note that bibliographic records do not show whether the coordinates were supplied from the piece cataloged or from another source. Using subfield $2 for source would provide an explicit indication of the source of the data.

2.2.5. Form of data recorded. Coordinate data may be recorded as bounding boxes or as separate points. Points have often been the only data available for catalogers and may be preferred for small places like buildings, sites, etc. Bounding boxes and polygons are richer data and may be preferred for other sorts of places if available. Either method may be used in the field currently, and institutional policy may determine the encoding.

3. PROPOSED CHANGES

In the MARC 21 Authority Format define field 034 with the following subfields:

034 Coded Cartographic Mathematical Data (R)

   Indicators
      First - Undefined
      Second - Type of ring
         # - Not applicable
         0 - Outer ring
         1 - Exclusion ring
   Subfield Codes
      $d - Coordinates--westernmost longitude (NR)
      $e - Coordinates--easternmost longitude (NR)
      $f - Coordinates--northernmost latitude (NR)
      $g - Coordinates--southernmost latitude (NR)

      $j - Declination--northern limit (NR)
      $k - Declination--southern limit (NR)
      $m - Right ascension--eastern limit (NR)
      $n - Right ascension--western limit (NR)
      $p - Equinox (NR)
      $r - Distance from earth (NR)

      $s - G-ring latitude (R)
      $t - G-ring longitude (R)
      $x - Beginning date (NR)
      $y - Ending date (NR)
      $z - Name of extraterrestrial body (NR)
      $2 - Source (NR)

      $6 - Linkage (NR)
      $8 - Field link and sequence number (R)

4. EXAMPLES

4.1. Authority records for Minnesota

Authority record for Minnesota: n 79021675

     035 -- ‡a (OCoLC)oca00255473
     040 -- ‡a DLC ‡b eng ‡c DLC ‡d DLC ‡d WaU
     043 -- ‡a n-us-mn
     151 -- ‡a Minnesota
     667 -- ‡a AACR 1 form: Minnesota.
     781 -0 ‡z Minnesota
     034 for the bounding box would be:
     034 -- ‡d W097.5000 ‡e W089.0000 ‡f N049.5000 ‡g N043.0000 $2 [code for Minnesota
     Geographic Data Clearinghouse]

Authority record for Todd County, Minn.: 81093353
     035 -- ‡a (OCoLC)oca00638538
     040 -- ‡a DLC ‡b eng ‡c DLC ‡d WaU
     043 -- ‡a n-us-mn
     151 -- ‡a Todd County (Minn.)
     451 -- ‡w nnaa ‡a Todd Co., Minn.
     781 -0 ‡z Minnesota ‡z Todd County
     034 for the bounding box would be:
     034 -- ‡d W095.1400 ‡e W094.6500 ‡f N046.3800 ‡g N045.7600 $2 [code for Minnesota
     Geographic Data Clearinghouse]

4.2. Authority record for Sweden showing period when Finland was part and then separated.

     010 -- ‡a n 79021184 ‡z sh 85131032
034 -- ‡d E0110000 ‡e E0320000 ‡f N0690000 ‡g N0550000 ‡x 17210000 ‡y 19171200 $2 [code for Hammond atlas of world history]
034 -- ‡d E0110000 ‡e E0240000 ‡f N0690000 ‡g N0550000 ‡x 19171200 $2 [code for The statesman's year-book]
035 -- ‡a (LCNA005)20051124071251.0
035 -- ‡a (OCoLC)oca00254984
040 -- ‡a DLC ‡b eng ‡c DLC ‡d DLC ‡d WaU ‡d OCoL
043 -- ‡a e-sw---
151 -- ‡a Sweden
451 -- ‡a Suéde
451 -- ‡a Zweden
451 -- ‡a Sverige
[etc.] 670 -- ‡a Gras, A. La Suède et ses populations, c1981: ‡b t.p. (Suède)
670 -- ‡a Francissen, P.W.H.M. De ondernemingsraad, 1977: ‡b t.p. (Zweden)
670 -- ‡a The statesman's year-book, 1995-1996: ‡b p. 1231 (Sweden; Konungariket Sverige (Kingdom of Sweden))
670 -- ‡a Hammond atlas of world history, 1999 ‡b p. 188-189 (Swedish Empire, 1721 [E 11 deg. to E 32 deg. / N 69 deg. to N 55 deg.]); p. 257 (Sweden, independence of Finland recognized Dec. 1917 [E 11 deg. to E 24 deg. /N 69 deg.to N 55 deg.])
670 ‡a National Geographic atlas of the world, 1995 ‡b p. 60-61 (Sweden [E 11 deg. to E 24 deg. / N 69 deg. to N 55 deg.])
781 0- $z Sweden

4.3. Authority record for a volcano

     010 -- ‡a sh 00004945
034 -- ‡d W0772200 ‡e W0772200 ‡f N0011300 ‡g N0011300 $2 [code for GEOnet] 035 -- ‡a (LCSU005)20030513140548.0
040 -- ‡a DLC |b eng |c DLC
151 -- ‡a Galeras Volcano (Colombia)
451 -- ‡a Pasto Volcano (Colombia)
451 -- ‡a Volcán de Pasto (Colombia)
451 -- ‡ a Volcán Galeras (Colombia)
550 -- ‡ w g |a Mountains |z Colombia
550 -- ‡ w g |a Volcanoes |z Colombia
670 -- ‡a Work cat.: 00054114: No apparent danger, 2001: |b CIP galley (Galeras, a 14,000 ft. volcano in S Colombia)
670 -- ‡a Volcanoes of the world: |b p. 267 (Galeras, Colombia)
670 -- ‡a Encyc. volcanoes: |b p. 466 (Galeras Volcano, Colombia)
670 -- ‡a Col. gaz. |b (Galeras Volcano, active Andean volcano, Nariño dept. SW Colombia, near Ecuador border, just W of Pasto. Sometimes called Pasto Volcano.)
670 -- ‡a GEOnet, Nov. 29, 2000 |b (Galeras, Volcán, cone,1 degree 13 minutes 00 seconds North, 77 degrees 22 minutes 00 seconds West; variant: Pasto, Volcán de; also Galeras, ppl)
781 -0 ‡z Colombia |z Galeras Volcano

4.4. Authority record for a star.

     010 -- $a sh2002008821
     034 -- $j  N0545600 $k N0545600  $m 134518 $n 134518 $p 2000.00 $r 78 $2 [code 
     for Cambridge star atlas]
     035 -- $a (LCSU005)20030117141546.0
     040 -- $a DLC $b eng $c DLC
     053 0- $a QB805
     151 -- $a Mizar
     451 -- $a 79 UMa
     451 -- $a Mirza
     451 -- $a Mizat
     451 -- $a Zeta UMa
     451 -- $a Zeta Ursae Majoris
     550 -- $w g $a Stars
     667 -- $a This heading is not valid for use as a geographic subdivision.
     670 -- $a Work cat.: 2002506586: Muller, K. Mizar : fur Ensembler, 1996/97, 2001: 
     $b verso t.p. (Mizar ([Zeta] UMa)
     670 -- $a Mizar WWW site, Dec. 2, 2002 $b (Mizar, Mizat, Mirza, 79 UMa,[Zeta] 
     Ursae Majoris)
     670 -- $a Ursa Major WWW site, Dec. 2, 2002 $b (Mizar; Zeta UMa)
     670 -- $a Cambridge star atlas, 2001 $b p. 35 (Mizar; UMa RA 13 hours 45.3 minutes; 
     Dec +54 degrees 56 minutes; Magnitude V2.23; Mv0.3; Spectral type A2; Distance 78 
     light-years)

4.5. Authority record for a planetary feature.

     010 -- $a sh2005020021
     034 -- $d W113.0000 $e W113.0000 $f N000.0000 $g N000.0000 $z Mars $2 [code for 
     Mars Global Surveyor]
     035 -- $a (LCSU005)20050317094941.0
     040 -- $a WaU $b eng $c DLC
     151 -- $a Pavonis Mons (Mars)
     451 -- $a Pavonis Mons Volcano (Mars)
     551 -- $w g $a Mars (Planet) $x Volcanoes
     551 -- $w g |$ Tharsis Montes (Mars)
     667 -- $a This heading is not valid for use as a geographic subdivision.
     670 -- $a Work cat.: Geological Survey (U.S.). Geologic map of Pavonis Mons Volcano, 
     Mars, 1998: $b text introd. (Pavonis Mons, the central of three large shield volcanoes 
     (Arsia, Pavonis, and Ascraeus Montes) that form the Tharsis Montes volcanic chain)
     670 -- $a Gazetteer of planetary nomenclature, via WWW, Jan. 11, 2005 $b(Pavonis Mons)
     670 -- $a Mars Global Surveyor MOC release no. MOC2-609, via WWW, Jan. 11, 2005 
     $b (Pavonis Mons. This is a broad shield volcano--similar to the volcanoes of Hawaii--
     located on the martian equator at 113 deg. W.  The volcano summit is near 14 km 
     (ca. 8.7 mi) above the martian datum (0 elevation); the central caldera (crater near 
     center of image) is about 45 km (ca. 28 mi.) across and about 4.5 km (ca. 2.8 mi.) deep)
     670 -- $a Volcanoes on Mars slide index, via WWW, Jan. 11, 2005 $b (Pavonis Mons)
     670 -- $a Volcano world, via WWW, Jan. 11, 2005: $b volcanoes/volcanoes of other 
     worlds/Mars/shield volcanoes/Tharsis Montes (three giant volcanoes known as the Tharsis 
     Montes; Arsia Mons, Pavonis Mons, and Ascreus Mons; these volcanoes lie in the center 
     of the Tharsis region, and they form a line nearly 1500 km long. They are nearly 700 km 
     apart) 

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