A knowledge graph and service for regional geologic time standards

Geologic time is an important dimension in geological research. Geologic time data are commonly collected from multiple sources in data-intensive studies of Earth's history and raise an issue of data cleansing and integration. A knowledge graph of the international geological time scale has been established to harmonize heterogeneous data to facilitate effective and efficient data-driven discovery. Although many regional geologic time standards are also used in various databases and literature, there is limited discussion or development of knowledge graph for them. In this research, we construct a knowledge graph for the geologic time standards in 17 regions at the Epoch and Age levels. This regional geologic time knowledge graph is integrated with the international geologic time knowledge graph as a comprehensive deep-time knowledge base. A SPARQL endpoint has been established to provide open and free online service to the knowledge base. Several use cases are presented here to demonstrate the functionality of the knowledge graph we built as well as its application in open data exploration. Our work addresses the shortage of machine-readable knowledge graphs for regional geologic time standards and will help accelerate geologic data integration from multiple sources in data-intensive studies. All data and code in this paper are made open source and are accessible on GitHub and Zenodo.