NE United States Gravity Maps

This map covers a variety of subtle geological/geophysical provinces. The highest levels of the geoid are found in the northeast corner of this region. Geoid highs generally indicate regions of excess mass, unaccounted for by a homogeneous ellipsoid, which acts as the reference surface (and solid) upon which the geoid (and anomalous potential) refers. Local lows in the geoid are seen in off the edge of the continental shelf, in deeper zones of the Atlantic Ocean A small NE/SW trending geoid "ridge" can be seen with some level of correspondence with the Appalachian Mountains.

Gravity anomaly maps are more revealing, as they feature more localized variations in the intensity of gravity. Again, we see gravity anomaly highs associated with mountain ranges.. These local anomaly highs are mostly associated with the remnants of the North American/African collision from a period several hundreds of millions of years ago.

Gravity anomaly lows are seen offshore at the sharper edges of continental shelves, and in regional lows mildly correlated with basins and major river valleys (e.g., the Hudson, Delaware and Shenandoah valleys).

Created: July 13, 2008
Last Updated: July 13, 2008