The gravity station data (1,522 records) were compiled by the Portland State University. This data base was received in August 1990. Principal gravity parameters include Free-air Anomalies and Complete Bouguer Anomalies (terrain correction applied). The observed gravity values are referenced to the International Gravity Standardization Net 1971 (IGSN 71). The gravity anomaly computation uses the Geodetic Reference System 1967 (GRS 67) theoretical gravity formula. The data are randomly distributed within the boundaries of the greater Portland area.

GEOSAT DATA: Gridded Gravity Anomalies for the Southern Ocean

GEOSAT DATA: Gridded Gravity Anomalies for the Southern Ocean

The gravity station data (55,907 records) were gathered by various governmental organizations (and academia) using a variety of methods. This data base was received in March 1993. Principal gravity parameters include Free-air Anomalies and Simple Bouguer Anomalies (no terrain correction applied). The observed gravity values are referenced to the International Gravity Standardization Net 1971 (IGSN 71) and the gravity anomaly computation uses the Geodetic Reference System 1967 (GRS 67) theoretical gravity formula. The spatial resolution of the data is randomly distributed within the boundaries of Minnesota.

The Central Andes gravity data (6,151 records) were compiled by Professor Gotze and the MIGRA Group. This data base was received in April, 1997. Principal gravity parameters include Free-air Anomalies and Bouguer Anomalies (terrain and mass corrected). The gravity station data have been adjusted to the International Gravity Standardization Net 1971 (IGSN 71). The gravity anomaly computation uses the Geodetic Reference System 1967 (GRS 67) theoretical gravity formula. The data are randomly distributed within the area bounded by 64 - 71 degrees West and 20 - 29 degrees South in the Central Andes of South America.

The Land and Marine Gravity 1999 Edition 2-volume CD-ROM set contains observed and derived land and marine gravity data contributed by many national and international organizations, from both the academic and government sectors. Approximately 70 percent of the data are observed values--regional station data collections (separated primarily by contributors) and absolute gravity measurements. Grids and other derived summary data sets represent another 30 percent of the data. In general, data record parameters include Latitude, Longitude, Observed Gravity and Elevation, Bouguer Gravity Anomaly (land), and Free- air Anomaly (ocean). In all cases, each data set contains associated documentation, including source contributor. Data are in binary format with ancillary files for conversion of the data to ASCII. On the Land Gravity CD- ROM, data sets are grouped into directories based on type: Absolute, Grids, Regional, Global, and Correlative (Geoids). The Marine Gravity CD-ROM has gravity data from 1,555 ocean surveys grouped by regional location of the survey. Directories exist for the Gulf of Mexico and Caribbean Sea, Indian Ocean, Mediterranean and Black Seas, North Pacific, South Pacific, North Atlantic and South Atlantic. Surveys which cross ocean areas are included in both regional directories. The marine gravity data were collected from ships operated between the years 1961 and 1996. The Marine gravity surveys are provided in a modified MGD77 format containing survey location, observed gravity and free air-anomaly. The 1999 Edition of Gravity Data is Year 2000 compliant. All date values are full 4-digit years. The GeoVu geophysical data browse and visualization software is also Year 2000 compliant. The compliance is inherent because there are no built-in date manipulation routines. However, GeoVu is written to run on specific platforms and operating systems. There is no guarantee that GeoVu will operate on platforms other than those indicated in the Software documentation.

Gravity anomalies and sea surface heights have been computed on a 0.125 degree grid in the ocean areas from a combined GEOS3/SEASAT/GEOSAT altimeter data set. This data base was received in March 1993. The area of data coverage is latitude 72N to 72S and longitude 0E to 360E.

Gravity anomalies and sea surface heights have been computed on a 0.125 degree grid in the ocean areas from a combined GEOS3/SEASAT/GEOSAT altimeter data set. This data base was received in March 1993. The area of data coverage is latitude 72N to 72S and longitude 0E to 360E.

The gravity station data (24,284 records) were compiled by the U. S. Geological Survey. This data base was received on February 23, 1993. Principal gravity parameters include observed gravity, Free-air anomalies and Bouguer anomalies. The observed gravity values are referenced to the International Gravity Standardization Net 1971 (IGSN 71). The gravity anomaly computation uses the Geodetic Reference System 1967 (GRS 67) theoretical gravity formula.

The gravity station data (32,152 records) were compiled by the U. S. Geological Survey. This data base was received on February 23, 1993. Principal gravity parameters include observed gravity, Free-air anomalies and Bouguer anomalies. The observed gravity values are referenced to the International Gravity Standardization Net 1971 (IGSN 71). The gravity anomaly computation uses the Geodetic Reference System 1967 (GRS 67) theoretical gravity formula.