Which datum does Web Mercator utilize?

Web Mercator utilizes the WGS84 datum, which is a widely accepted reference system used for global positioning and mapping. WGS84 is an Earth-centered, Earth-fixed coordinate reference system that is essential for applications requiring GIS, such as web mapping services like Google Maps and OpenStreetMap.

The WGS84 datum is particularly well-suited for use in web applications because it provides a consistent set of geographic coordinates that are compatible across various systems and devices, ensuring that digital maps and geographic data align correctly on a global scale. This datum is defined by its geographic coordinate system (latitude and longitude) and projection which allows the flat representation of the Earth’s surface.

In contrast, other datums mentioned, such as WGS72 and NAD83, are not used in Web Mercator. WGS72 is an older version of the WGS system with limited applicability compared to WGS84, while NAD83 is primarily utilized in North America. ETRS89 is specifically tailored for the European region and is based on the same principles as WGS84, but it is not the framework used by Web Mercator. Thus, the correct association of Web Mercator with WGS84 highlights its relevance for modern mapping applications.