SW United States Gravity Maps

This map covers some very active geological/geophysical provinces. The highest levels of the geoid are found in a Colorado Plateau region in Utah, with a general rise progress from SW to NE. 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 highs are associated with the Sierra Nevada Mountains and with the Baja Peninsula. Local lows in the geoid are seen in the deeper regions of the Pacific Ocean with local "shelves" in the central valley of California.

Gravity anomaly maps feature more localized variations in the intensity of gravity. Again, we see gravity anomaly highs associated with mountain ranges. Particularly strong positive gravity anomalies appear clearly associated with Sierra Nevada and Coast Range mountains in California, the mountain ranges running along the spine of the Baja Peninsula in Mexico and the Colorado Plateau in southern Utah and southern Arizona.

Gravity anomaly lows are seen just offshore and in regional lows mildly correlated with basins across land masses. The Central Valley of California is particularly notable, as are sporadic lows along the Colorado River basin.

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