Raster created using a minimum curvature gridding algorithm
Cell size: 1000 m
Units: mgal
Data collected using La Coste-Romberg gravimeters and elevations were determined
using micro-barometers except in cases where gravity stations were located at a
spot height or trigonometric beacon. In the 1990s GPS was used.The measurements
were tied to the International Gravity Standardisation Net values and were referred
to the gravity formula based on the 1967 geodetic reference system.
Corrections that were applied are:
Latitude correction: = 978031.8*(1+0.0053024*(sin2φ)-0.0000058*sin2(2 φ)
Where φ is in radians
This correction is subtracted from the absolute gravity value
Free air correction = 0.3086 * Elevation
Where elevation is in meters (elevation difference between observation point and datum (sea level))
This correction is added to the latitude corrected data
Bouguer slab correction = 0.04193 * 2.67 * Elevation
2.67 is the density of the slab in g/cm3
Where elevation is in meters
This correction is subtracted from to the free air corrected data