This database is maintained by the Earth System Science Center (ESSC) at The Pennsylvania State University. It was developed intially to support ESSC's Earth Observation System (EOS) interdisciplinary investigation into "The Global Water Cycle: Extension Across the Earth Sciences". It has subsequently been extended to support other projects.

The database contains a variety of geographically referenced data sets, representing both data generated by ESSC investigators, and other data needed to support their investigations. The actual data and most metadata are stored in a directory tree, with d ata for progressively smaller geographic areas being stored at greater depths in the tree.