Potential field data (gravity and magnetic measurements) are both useful and cost-effective tools for many geologic investigations. Significant amounts of these data are traditionally in the public domain. A new magnetic database for North America was released in 2002, and as a result, a cooperative effort between government agencies, industry, and universities to compile an upgraded digital gravity anomaly database, grid, and map for the conterminous United States was initiated and is the subject of this paper. This database is being crafted into a data system that is accessible through a Web portal. This data system features the database, software tools, and convenient access. The Web portal will enhance the quality and quantity of data contributed to the gravity database that will be a shared community resource. The system's totally digital nature ensures that it will be flexible so that it can grow and evolve as new data, processing procedures, and modeling and visualization tools become available. Another goal of this Web-based data system is facilitation of the efforts of researchers and students who wish to collect data from regions currently not represented adequately in the database. The primary goal of upgrading the United States gravity database and this data system is to provide more reliable data that support societal and scientific investigations of national importance. An additional motivation is the international intent to compile an enhanced North American gravity database, which is critical to understanding regional geologic features, the tectonic evolution of the continent, and other issues that cross national boundaries.

Geospatial Network (GeoNet) is a distributed information system accessible through the Internet that will permit users from the geoscience community to share and contribute knowledge from the transition zone between the Colorado Plateau and the Basin and Range province. Specifically, the goals of GeoNet are to facilitate the access, analysis, and visualization of geospatial data for use by scientists, policymakers, educators, and the general public. The types of geospatial data provided through GeoNet include satellite imagery, gravity, heat flow, digital elevation models, remote sensing, seismicity, active faults, and basic geographic data. This paper, written as a primer, describes how state-of-the-art technology is being used to realize GeoNet's goals. It also discusses GeoNet's layered architecture and shows how this architecture supports software applications deployed as service-oriented components. Ontologies based on the emerging OWL Web ontology language standard are used to enhance knowledge discovery. Use-case scenarios describe the features of GeoNet and the expected sequences of interaction between GeoNet and different classes of users. GeoNet's design will permit its functionality and data sets to be integrated with the GEON (Geosciences Network) grid and, thus, will contribute to the larger geoscience community.