The gravity field observed at the earth's surface is the superposition of the earth's main field and more subtle effects related to geologic structure [density differences]. Corrections are made to the observed gravity values to remove the earth's main field and to remove gravitational effects due to changes in elevations and topographic masses. Once these corrections have all been made to the data, the resulting gravity field is called the complete Bouguer anomaly, which reflects subsurface anomalous density distributions and is the standard anomaly for geological analysis (Hildenbrand and Kucks, 1984).
The gravity data set presented for your use is a gridded set prepared from the complete bouguer gravity anomaly data set for Ohio. This data has been extracted from:
Hittelman, A., D. Dater, R. Buhmann, and S. Racey, 1994, Gravity CD-ROM and User's Manual (1994 Edition). National Oceanic and Atmospheric Administration, National Geophysical Data Center, Boulder, Colorado.
The user should also refer to the following reference for a discussion of the original data and data reduction methods.
Hildenbrand, T. G., and Kucks, R. P., 1984, Complete Bouguer gravity anomaly map of Ohio: U.S. Geological Survey Geophysical Investigations Map GP-962.
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