Permafrost and seasonally frozen ground regions occupy approximately 24% and 60%, respectively, of the exposed land surface in the Northern Hemisphere. The actual area underlain by permafrost is approximately 12% to 18% of the exposed land area^*. Frozen ground data and information collected over past decades, and to be collected in the future, are critical for fundamental process understanding, environmental change detection, impact assessment, model validation, and engineering applications. However, much of this information remains widely dispersed and unavailable to the science and engineering communities, and some data are in danger of being lost permanently.

The International Permafrost Association (IPA) has developed a strategy for data and information management to meet the requirements of cold regions science, engineering, and modeling communities. A central component of this strategy is the Global Geocryological Data (GGD) system, an internationally distributed system linking investigators and data centers around the world.

The World Data Center (WDC) for Glaciology at Boulder and the National Snow and Ice Data Center (NSIDC) in collaboration with the International Arctic Research Center (IARC) serve as a central node of the GGD. The WDC developed the Circumpolar Active-Layer Permafrost System (CAPS) CD-ROM set (Version 2, 2003), a five-year compilation of permafrost and frozen ground-related data and information products with a global perspective. Updates and corrections to CAPS can be found on the Addendum page.

The Frozen Ground Data Center has now published the content of CAPS on this web site and continues to expand and improve access to frozen ground data.

Please help us realize our goal of expanding and improving access to frozen ground data by contributing your frozen ground data and metadata.

^*Zhang, T., J.A. Heginbottom, R.G. Barry, and J. Brown. 2000. Further statistics on the distribution of permafrost and ground ice in the Northern Hemisphere. Polar Geog. 24(2): 126-131.