| ANWR and Alaska Peninsula Gravity Data |
| The gravity station data (1252 records) were compiled by the U.S. Geological Survey
and the State of Alaska Division of Geological & Geophysical Surveys. This data base
was received in August, 1984. Principal gravity parameters include Free-air Anomalies
and Simple Bouguer Anomalies (no terrain correction applied) for the Alaska Peninsula.
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 northeast Alaska including the Arctic National Wildlife Range (ANWR)
and the Alaska Peninsula. Note that the original USGS Open File Report by D. F. Barnes
mentions the use of the 1931 International Ellipsoid for gravity reduction but this
is believed to have subsequently been changed to the GRS 67 system. |
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