Table of Contents for this Document File: Name of File Contributing Source File directory/location Information on the region covered Variable Table Format File Sample Data Variable File Additional Documentation ==================================================================== ==================================================================== ==================================== Variable Table The variable table contains a list of parameters contained in the data as well as information on the existence of histograms which can be viewed in GeoVu. File lao.tab for this catalog follows ==================================== DATA SET TITLE: lao PRINCIPAL INVESTIGATOR: CONTRIBUTING ORGANIZATION: LA0 Elevation: LOCATION and NAME: (Alternate Abbreviation for LAO) LAO C LATITUDE: 46.6865 N LONGITUDE: 106.22 W LAO C Elevation: 744.0 LOCATION and NAME: LASA Array LAO Large Aperture Seismic Array (LASA) , Montana, USA. DATA FILE: lao.bin #\data\globecat\lao\lao.bin NUMBER OF RECORDS: 3832 ASCII FILE SIZE: 314224 BINARY FILE SIZE: 298896 SUMMARY: Lassa Array Observatory events, 1966-1971 Like other arrays, the Lassa Array Observatory (LAO) determines the locations of events in the LAO catalog from multiple instrument readings within the array. By contrast, event locations reported in multiple observatory catalogs (like PDE or ISC) are determined from observations contributed from stations around the world. This has led to errors in stated positions of events in the LAO catalog. For example, in the LAO data there is an apparent strong line of seismicity at 103 degrees radially distant from LAO. This line runs through central South America and Africa, and does not represent real events. Caution should be taken in using these data. 1. VARIABLE NAME HISTOGRAM NAME 2. ASCII FORMAT BINARY FORMAT NO. & MIN/MAX VALUES Stat End Type Prc Stat End Type Prc Min. Max. #nonzero source SOURCE.CST 1 3 char 0 1 3 char 0 LAO LAO 3832 century_and_year CENTURY_.LST 4 8 short 0 57 58 short 0 1966 1971 3832 month MONTH.LST 9 10 short 0 59 60 short 0 1 12 3832 day DAY.LST 11 12 short 0 61 62 short 0 1 31 3832 hour HOUR.LST 13 14 short 0 63 64 short 0 1 23 3706 minute MINUTE.LST 15 16 short 0 65 66 short 0 1 59 3743 second SECOND.LST 17 19 short 1 67 68 short 1 1 59 3768 latitude_abs NO HISTOGRAM 20 24 long 3 NOT IN BINARY latitude_ns NO HISTOGRAM 25 25 char 0 NOT IN BINARY longitude_abs NO HISTOGRAM 26 31 long 3 NOT IN BINARY longitude_ew NO HISTOGRAM 32 32 char 0 NOT IN BINARY depth DEPTH.LST 33 35 short 0 69 70 short 0 10 250 265 mb_magn MB_MAGN.LST 36 38 short 2 14 15 short 2 3 3 1 MB NO HISTOGRAM 39 40 constant 0 NOT IN BINARY flag_isoseismal FLAG_ISO.CST 41 43 char 0 16 18 char 0 0 0 0 intensity INTENSIT.CST 44 44 char 0 19 19 char 0 0 0 0 flags_ngdc FLAGS_NG.CST 45 50 char 0 20 25 char 0 0 0 0 flag_diastrophic FLAG_DIA.CST 45 45 char 0 26 26 char 0 0 0 0 flag_tsunami FLAG_TSU.CST 46 46 char 0 27 27 char 0 0 0 0 flag_seiche FLAG_SEI.CST 47 47 char 0 28 28 char 0 0 0 0 flag_volcanism FLAG_VOL.CST 48 48 char 0 29 29 char 0 0 0 0 flag_non_tectonic FLAG_NON.CST 49 49 char 0 30 30 char 0 0 0 0 flag_infrasonic FLAG_INF.CST 50 50 char 0 31 31 char 0 0 0 0 Flinn_Engdahl_region FLINN_EN.LST 51 53 short 0 32 33 short 0 4 728 3810 ms_local_magn MS_LOCAL.LST 54 55 short 1 34 35 short 1 0 0 0 MS NO HISTOGRAM 56 57 constant 0 NOT IN BINARY z_h Z_H.CST 58 58 char 0 36 36 char 0 0 0 0 flag_cultural FLAG_CUL.CST 59 59 char 0 37 37 char 0 0 0 0 flag_other FLAG_OTH.CST 60 60 char 0 38 38 char 0 0 0 0 magn_other MAGN_OTH.LST 61 63 short 2 39 40 short 2 1 6 3393 magn_other_authority MAGN_OT1.CST 64 66 char 0 41 43 char 0 LAO LAO 3393 international_data_exchange_event INTERNAT.CST 67 67 char 0 44 44 char 0 0 0 0 flag_depth_control_PDE FLAG_DEP.CST 68 68 char 0 45 45 char 0 0 0 0 number_of_stations_or_quality NUMBER_O.CST 69 71 char 0 46 48 char 0 1 27 3808 time_authority TIME_AUT.CST 72 72 char 0 49 49 char 0 0 0 0 ml_magn_local ML_MAGN_.LST 73 75 short 2 50 51 short 2 3 4 16 ml_magn_local_scale ML_MAGN1.CST 76 77 char 0 52 53 char 0 ML ML 16 ml_magn_local_source ML_MAGN2.CST 78 80 char 0 54 56 char 0 LAO LAO 16 latitude LATITUDE.LST NOT IN ASCII 4 7 long 3 -76 88 3772 longitude LONGITUD.LST NOT IN ASCII 8 11 long 3 -180 180 3830 depth_negate DEPTH_NE.LST NOT IN ASCII 12 13 short 0 -250 0 265 year_decimal YEAR_DEC.LST NOT IN ASCII 71 78 double 10 1966.831 1971.483 3832 ==================================== Format File The format file is a listing of the variable names, types and positions within the binary and ASCII files. The file is composed of two parts - the first section is the format of the ASCII file, the second, the format of the binary file. The ASCII format file *.af must be renamed to *.afm to be used with the Freeform utility. Likewise, the binary format file *.bf must be renamed to *.bfm. The structure of this file is: Field 1: Variable name Field 2: First position of variable in line Field 3: Last position of variable in line Field 4: Type of variable Field 5: Precision of variable **Refer to Freeform user's manual for further information See format file lao.fmt in this directory ==================================== ======================================================== Sample Data A representative sample of data records showing the first 10 lines and the last 10 lines of the ASCII data file(i.e. the .dat file). The first and last 10 records of lao.dat follow ======================================================== LAO 19661031145334018000S 65000W 0 120 450LAO 1 LAO 19661031171030017000S170000W 0 174 500LAO 1 LAO 19661031210952017000S 68000W 0 120 450LAO 1 LAO 19661101063949027000S172000E 0 606 500LAO 5 LAO 19661102113329087000N109000W 0 634 400LAO 11 LAO 19661103133258312000S 75000W 0 116 450LAO 3 LAO 19661103195930254000N 72000W 0 443 400LAO 1 LAO 19661104221419736000N101000E 0 325 500LAO 1 LAO 19661106033838117000S 13000W 0 410 500LAO 1 LAO 19661106192710938000S 39000W 0 409 500LAO 1 . . . . LAO 19701228060414036600N 25500E 0 369 370LAO 1 LAO 19701228071625010400S120700E 0 287 2 LAO 19701228074306057600N 18100W 0 402 390LAO 4 LAO 19701228091858017200N 94000W 0 061 390LAO 1 LAO 197012290309180 7700S161500E 0 193 470LAO 1 LAO 197012300253150 1400N 81800W 0 104 340LAO 1 LAO 19701230030529054100N160800E 0 218 360LAO 2 LAO 197012300314260 1400S 77600W 0 107 330LAO 1 LAO 197012300321190 5800S 26100W 0 409 390LAO 1 LAO 19710626074107023000S 71000W 0 121 380LAO ==================================== Variable File This file contains statistical information on each of the variables in the data set. The variable file lao.var for this catalog follows ==================================== Input file : lao.bin Input format file: lao.fmt No requested precision, Approximate number of sorting bins = 100 source: 3832 values read minimum: LAO found at record 1 maximum: LAO found at record 1 Summary file: source.cst Histogram data precision: 0, Number of sorting bins: 83 latitude: 3832 values read minimum: -75.400 found at record 1931 maximum: 88.700 found at record 3774 Summary file: latitude.lst Histogram data precision: 0, Number of sorting bins: 89 longitude: 3832 values read minimum: -179.500 found at record 2870 maximum: 180.000 found at record 84 Summary file: longitud.lst Histogram data precision: 0, Number of sorting bins: 29 depth_negate: 3832 values read minimum: -250 found at record 2961 maximum: 0 found at record 1 Summary file: depth_ne.lst Histogram data precision: 0, Number of sorting bins: 2 mb_magn: 3832 values read minimum: 0.00 found at record 1 maximum: 3.80 found at record 2745 Summary file: mb_magn.lst flag_isoseismal: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_iso.cst intensity: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: intensit.cst flags_ngdc: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flags_ng.cst flag_diastrophic: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_dia.cst flag_tsunami: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_tsu.cst flag_seiche: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_sei.cst flag_volcanism: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_vol.cst flag_non_tectonic: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_non.cst flag_infrasonic: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_inf.cst Histogram data precision: 0, Number of sorting bins: 147 Flinn_Engdahl_region: 3832 values read minimum: 1 found at record 451 maximum: 729 found at record 839 Summary file: Flinn_En.lst Histogram data precision: 0, Number of sorting bins: 1 ms_local_magn: 3832 values read minimum: 0.0 found at record 1 maximum: 0.0 found at record 1 Summary file: ms_local.lst z_h: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: z_h.cst flag_cultural: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_cul.cst flag_other: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_oth.cst Histogram data precision: 0, Number of sorting bins: 7 magn_other: 3832 values read minimum: 0.00 found at record 16 maximum: 6.30 found at record 931 Summary file: magn_oth.lst magn_other_authority: 3832 values read minimum: found at record 16 maximum: LAO found at record 1 Summary file: magn_ot1.cst international_data_exchange_event: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: internat.cst flag_depth_control_PDE: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: flag_dep.cst number_of_stations_or_quality: 3832 values read minimum: found at record 1044 maximum: 27 found at record 1492 Summary file: number_o.cst time_authority: 3832 values read minimum: found at record 1 maximum: found at record 1 Summary file: time_aut.cst Histogram data precision: 0, Number of sorting bins: 3 ml_magn_local: 3832 values read minimum: 0.00 found at record 1 maximum: 4.00 found at record 1506 Summary file: ml_magn_.lst ml_magn_local_scale: 3832 values read minimum: found at record 1 maximum: ML found at record 1506 Summary file: ml_magn1.cst ml_magn_local_source: 3832 values read minimum: found at record 1 maximum: LAO found at record 1506 Summary file: ml_magn2.cst Histogram data precision: 0, Number of sorting bins: 6 century_and_year: 3832 values read minimum: 1966 found at record 1 maximum: 1971 found at record 3832 Summary file: century_.lst Histogram data precision: 0, Number of sorting bins: 12 month: 3832 values read minimum: 1 found at record 159 maximum: 12 found at record 72 Summary file: month.lst Histogram data precision: 0, Number of sorting bins: 31 day: 3832 values read minimum: 1 found at record 4 maximum: 31 found at record 1 Summary file: day.lst Histogram data precision: 0, Number of sorting bins: 24 hour: 3832 values read minimum: 0 found at record 20 maximum: 23 found at record 130 Summary file: hour.lst Histogram data precision: 0, Number of sorting bins: 60 minute: 3832 values read minimum: 0 found at record 28 maximum: 59 found at record 7 Summary file: minute.lst Histogram data precision: 0, Number of sorting bins: 60 second: 3832 values read minimum: 0.0 found at record 93 maximum: 59.4 found at record 39 Summary file: second.lst Histogram data precision: 0, Number of sorting bins: 29 depth: 3832 values read minimum: 0 found at record 1 maximum: 250 found at record 2961 Summary file: depth.lst Histogram data precision: 0, Number of sorting bins: 6 year_decimal: 3832 values read minimum: 1966.8318370751 found at record 1 maximum: 1971.4830690956 found at record 3832 Summary file: year_dec.lst ==================================== The bibliographic file lao.bib for this catalog follows ==================================== This is the NGDC Bibliography for Large Earthquakes "Destructive and Near Destructive Earthquakes of Puerto Rico and Nearby Regions." House of Representatives Document No. 269. Sixty-Sixth Congress, First Session. (1946): 1-4. "Destructive and Near-Destructive Earthquakes in California and Western Nevada: 1769 - 1932." Coast and Geodetic Survey (1932): 1-14. "Earthquakes in the Various States." Publication of the U.S. Printing Office GPO Jacket No 777-941 (1963): 106-18. "Puerto Rico Earthquakes, 1919 - 1937." Data Complied From Monthly Weather Review (1937): 1-2. "Research of Seismicity in Seismic Zones of Less Activity: Central Cuba." Publication of the Soviet Geophysical Committee and the Academy of Sciences of the USSR (1983): 1-134. ---, Authors. Catalog of Significant Earthquakes 2000 B.C. - 1979 Including Quantitative Casualties and Damage. Soft Cover Booklet. Boulder, CO: World Data Center A for Solid Earth Geophysics, U.S. Department of Commerce, NOAA, Environmental Data and Information Service, 1981. Report SE-27. ---. "Seismicity of the Earth." Bulletin of the Geological Society of America Vol. 56 (1945): 603-68. ---. "The Puerto Rico Earthquakes of October-November, 1918." The Bulletin of the Seismological Society of America Vol. 9.No. 4 (1919): 95-127. ---. "The Seismicity of the Caribbean Region." Journal of Geophysical Research Vol. 70.No. 20 (1965): 5065-74. . "Magnitude 8 and Greater Earthquakes, 1897-1972 Inclusive." One-page, copy. . "Major Earthquakes." One-page, copy. Boulder, Colorado: National Geophysical and Solar-Terrestrial Data Center. . "Significant Earthquake Activity, 1972." One-page, copy. . "World Seismicity and Volcanic Activity in the Year 1974." One-page, copy. Abe, K. "Size of Great Earthquakes of 1837-1974 Inferred From Tsunami Data." Journal of Geophysical Research Volume 84.No. B4 (1979): Pages 1561-68. Anonymous. Great Earthquakes. AnonymousVolume 1, No. 2. Washington, D.C.: U.S. Congress, 1888. Barazangi, M. and Dorman J. "World Seismicity Maps Compiled From ESSA, Coast and Geodetic Survey, Epicenter Data, 1961 - 1967." Bulletin of the Seismological Society of America Vol. 59.No. 1. (1969): 1-11. Benhallou, H. "Les Catastrophes Séismiques De La Region D'Echelif Dans Le Contexte De La Seismicite Historique De L"Algerie." Large Soft Cover Book. Presentee a L'Universite Des Sciences Et De La Technologie Houari Boumediene Alger, 1985. British Association for the Advancement of Science. Catalogue of Earthquakes 1918-1924. Piccadilly, London: British Association for the Adbancement of Science, 1928. No. 21. Båth, M. Duda S. J., AuthorsSoft Cover Booklet. M. Duda S. J. Båth. Report No. 1-79 ed. Uppsala, Sweden: Seismological Institute, 1979. Report No. 1-79. Coffman, J. L. and von Hake C. A. "Earthquake History of The United States." Publication of the Environmental Data Service of NOAA .Publ. 41-1 (1973): 1-208. Coffman, J. L. and von Hake C. A. Stover C. W., Editors. Earthquake History of the United States. Hard Back (3) and Soft Cover Book (two copies). Publication 41-1 Revised Edition (Through 1970) Reprinted 1982 with Supplement (1971-1980) ed. U.S. Government Printing Office, Washington, D.C. and Boulder, CO: U.S. Department of Commerce, and U.S. Department of the Interior, 1973. 41-1. Coffman, J. L., Editor. Earthquake History of the United States. Soft Cover Booklet (one copy). Editors. J. L. Coffman. 1979 ed. Boulder, CO: U.S. Department of Commerce, National Oceanic and Atmospheric Administration and U.S. Department of the Interior, Geological Survey., 1979. Publication 41-1. Couch, R. Victor L. and Keeling K. Costal and Offshore Earthquakes of the Pacific Northwest. Corvallis, Oregon: School of Oceanography at Oregon State University, 1974. Crampin, S. Fyfe C. J. Bickmore D. P. and Linton H. W. "Atlas of Seismic Activity 1909-1968." Soft Cover Booklet, Journal. Seismological Bulletin No. 5 (1976). DeNevi, D. Earthquakes. Millbrae, California: Celestial Arts, 1977. Ganse, R. A. Nelson J. B. "Significant Earthquake File." Xerox Copy. Boulder, CO: NOAA/National Geophysical and Solar-Terrestrial Data Center. Ganse, R. A. and Nelson J. B. "Catalog of Significant Earthquakes: 2000 B.C. - 1979." Publication of the Environmental Data and Information Service .July (1981): 1-153. Gupta, H. K. and Negi J. G. "High Magnitude Global Seismicity and Lateral Velocity Gradients." Vol. 80 (1970): 92-101. Gutenberg, B and Richter C. F. "Seismicity of the Earth." Bulletin of the Geological Society of America Vol. 56 (1945): 603-68. Gutenberg, B. and Richter C. F. "Seismicity of the Earth." Geological Society of America Special Paper No. 34 (1941): 1-131. Hall, M. Earthquakes in Jamaica From 1688 to 1919. Kingston, Jamaica: Government Printing Office, 1922. Hall, M. M. A. F. R. A. S. F. R. Met S., Government MeteorologistSoft Cover Booklet. Barrister-At-Law, Government Meteorologist. M. Hall. Kingston, Jamaica: Government Printing Office, 1922. Hays, W. W. Algermissen S. T. Espinosa A. F. Perkins D. M. Rinehart W. A. Guidelines for Developing Design Earthquake Response Spectra. Golden, CO: U.S. Geological Survey, 1974. Heck, N. H. "Destructive and Extremely Severe Earthquakes in California 1769 - 1927." Report for the Division of Terrestrial Magetism and Seismology (1931): 1-12. Heck, N. H. Eppley R. A., Editors. Earthquake History of the United States. Soft Cover Booklet. Editors. N. H. Eppley R. A. Heck. Revised (1938, 1956) Editions ed. Washington, D.C.: U.S. Government Printing Office, 1938. No. 41-1. Heck, N. H. and Davis R. M. Jr. "A List of Earthquakes Published in 1688." Reprinted From Bulletin of the Seismological Society of America Volume 36.No. 4 (1946): Pages 363-72. Heck, N. H. and Wood H. O., Editor. Earthquake History of the United States. Soft Cover Booklet. N. H. Heck. Original Edition (1938)(2 Copies), Revised (1947) Edition, Revised 1951 Edition. ed. Washington, D.C.: United States Government Printing Office, 1938. Heck, N. H., Division Chiefforty typewritten pages. Linehan, D. Compilation of Earthquakes in Northeastern United States and Eastern Canada 1534 - 1957. Weston Geophysical Research Inc. Magnati, D. V.Thirteen-page, typewritten report. Map Showing Recomputed Hypocenters of Earthquakes in the Eastern and Central United States and Adjacent Canada, 1925-1980. Seismic. Reston, Virginia: U.S. Department of Interior, USGS, 1984. McClain, W. C. and Myers O. H.45 pages of 8 1/2" X 11 bound copy. Springfield, Virginia: U. S. Department of Commerce, 1970. ORNL-4582. Montandon, F. Les Tremblements De Terre Destructeurs En Europe, Catalogue Par Territoires Séismiques, De L'an 1000 à 1940 (Destructive Earthquakes in Europe, Catalog of Seismic Stations, From 1000-1940). Geneve: à l'Union internationale de Secours, Genéva, 1953. Nottis, G. N. Editor New York State Geological Survey. Epicenters of Northeastern United States and Southeastern Canada, Onshore and Offshore; Time Period 1534-1980. Series No. 38, Map and Chart ed. Albany, N.Y.: The University of the State of New York, The State Education Department, Feb. 1983. Nuttli, O. W., AuthorSoft Cover Booklet. O. W. Nuttli. First Edition ed.Volume NO. 1, Monograph Series, Central United States Earthquake Consortium. Marion, Illinois: Funding provided by the Federal Emergency Management Agency, 1987. Person, W., CompilerXerox Copy. 1983. Poeschel, K. R. Stromberg P. A. Seismic Safety Commission Staff, Project DirectorSoft Cover Booklet. Eureka, CA: State of California Seismic Safety Commission, 1980. SSC 80-3. Reid, H. F. and Taber S. "The Porto Rico Earthquake of 1918." House of Representatives Publication (66th Congress, 1st Session) Document No. 269 (1919): 3-74. Results of Researches on the International Geophysical Projects. Research of Seismicity in Seismic Zones of Less Activity (Central Cuba). Moscow, Russia: Nauka, 1983. Ritsema, A. R. and Karnik V. "European Catastrophic Earthquakes." Tectonophysics (International Journal of Geotectonics and the Geology and Physics of the Interior of the Earth Volume 53.No. 3/4 (1979): Pages 155-337. Rutten, L. M. R. and Van Raadshooven B. "On Earthquake Epicentres and Earthquake Shocks Between 1913 and 1938 in the Region Between 0° and 30° N and 56° and 120° W." Nederl. Akad. Wet., Verh. Tweede Sectie, Deel XXXIX.No. 4 (1940): Pages 1-44. Ryall, A. Slemmons D. B. & Gedney L. D. "Seismicity, Tectonism, and Surface Faulting in the Western United States During Historic Time." Bulletin of the Seismological Society of America Vol. 56.No. 5 (1966): 1105-35. Seismicity Map of the Conterminous United States and Adjacent Areas, 1965-1974 and 1975 - 1984. Seismic. Reston, Virginia: U.S. Department of Interior, USGS, 1977. Significant Earthquakes 1900 - 1979. Seismic. Boulder, CO: National Geophysical and Solar-Terrestrial Data Center and World Data Center A for Solid Earth Geophysics, with support from Office of U.S. Foreign Disaster Assistance Agency for International Development. Sykes, L. R. and Ewing M. "The Seismicity of the Caribbean Region." Journal of Geophysical Research Vol. 70.No. 20 (1965): 5065-74. Thomas, Alun J. "World Seismic Regions (Gutenberg and Richter 1954)." Twentieth Century Earthquakes, 1:, 1900 - 1919, 2:, 1920 - 1929, 3:, 1930 - 1939, 4:, 1940 - 1949, and Geological Events 1979 and 1980. Xerox CopyGeology Schools Service, National Museum of Wales, 1981. Wood, H. O. Allen M. W. and Heck N. H., Chief, Division of Terrestrial Magnetism and SeismologyHard Cover Book. United States Government Printing Office: U.S. Department of Commerce, Coast and Geodetic Survey, 1934. Special Publication No. 191. Wood, H. O. Heck N. H. and Eppley R. A., Editors. Earthquake History of the United States. Soft Cover Booklet. Editors. H. O. Heck N. H. and Eppley R. A. Wood. Revised (1960) Edition ed. U.S. Government Printing Office, Washington, D.C.: U.S. Department of Commerce, Coast and Geodetic Survey, 1961. No. 41-1. Wood, H. O. and Heck N. H., Editors. Earthquake History of the United States. Soft Cover Booklet. Editors. H. O. and Heck N. H. Wood. Revised (1951) Edition ed. United States Government Printing Office, Washington, D.C.: U.S. Department of Commerce, Coast and Geodetic Survey, 1951. Woollard, G. P. A Catalogue of Earthquakes in the United States Prior to 1925 (Based on Unpublished Data Compiled by Harry Fielding Reid and Published Sources Prior to 1930). Honolulu, Hawaii: Hawaii Institute of Geophysics, University of Hawaii, June 1968. HIG-68-9 Data Report No. 10. ======================================================== Additional Documentation Any other files contributed to or generated by NGDC as documentation for the data base follows. ========================================================