Extent of available data.
This data layer depicts differences in the gravity field of the underlying geology. It is the Minnesota Geological Survey's 2019 upgrade of the gravity database and is based on calculations of the Bouguer gravity anomaly, which is corrected for the height at which it is measured. The variations in the Bouguer gravity values, here in units of milliGals, are related to anomalous density distributions of geological units within the Earth. Gravity data is a key basis for geological mapping, and it helps geologists and geophysicists understand the internal structure of Earth in general, and the bedrock geology of Minnesota in detail.