What is the name of the gravity-based geodetic datum prevalent in North America?

The prevalent gravity-based geodetic datum in North America is known as NAVD88, which stands for the North American Vertical Datum of 1988. This datum is fundamentally important for establishing elevation references across North America. It serves as a standard to which elevation measurements can be reported, allowing for consistency and accuracy in the representation of terrain heights and depths.

NAVD88 is based on a network of benchmarks and uses adjustments derived from gravity measurements, making it essential for various applications including hydrology, civil engineering, and land surveying. This datum replaced the older National Geodetic Vertical Datum of 1929 (NGVD29), and was developed to provide improved accuracy over the older system.

In contrast, WGS 84 is a global positioning standard used mainly for horizontal positioning, while EPSG codes and SRID integers are related to referencing systems and do not specifically denote any gravity-based vertical datum. Therefore, NAVD88 is the correct answer because it directly addresses the need for a reliable vertical reference specifically for North America based on gravitational measurements.