A-CAP home

12 March 2009

Antarctic Ice Velocity Data Now Available through A-CAP

Sign up for the A-CAP RSS Feed rss icon for automatic notification of updates.

The NSIDC Antarctic Cryosphere Access Portal (A-CAP) now contains VELMAP Antarctic ice flow velocity data. The goal of VELMAP is to compile ice flow velocity for the whole Antarctic continent. Understanding ice flow and its temporal changes is essential to answering questions about whether Antarctic ice volume is changing and how it may change in the future. Since changes in Antarctic ice have an impact on sea level, this is a problem with global importance. For more information on the project, see the VELMAP Web site.

The VELMAP collection on A-CAP is composed of 47 selectable layers. Each of these can be displayed as either a data location map, to help differentiate the different layers, or a graded ice velocity map. The opacity of these maps is also configurable. All layers are queryable so that a user can determine the ice velocity, bearing/azimuth, collection date, station name, and magnitudes of error for each point observation. As with all A-CAP layers, the info icon opens a pop-up window with pertinent citation and summary information about each VELMAP layer.

Please use the following text to cite the VELMAP collection:

  • Scambos, T., B. Raup, and J. Bohlander. Compilers. 2001. VELMAP: Antarctic ice velocity data. Boulder, Colorado USA: National Snow and Ice Data Center. Digital Media. Available at http://nsidc.org/data/velmap/.


acap map with velmap, animation
Figure 1. Animation showing VELMAP data on A-CAP maps. View legend.
—Credit: NSIDC

A-CAP is a geo-visualization and data download tool developed at the National Snow and Ice Data Center (NSIDC) Antarctic Glaciological Data Center (AGDC). A-CAP provides AGDC data and other Antarctic-wide parameters, including glaciology, ice core data, snow accumulation, satellite imagery, Digital Elevation Models (DEM's), sea ice concentration, and many other cryosphere-related scientific measurements. For more information on how to access data using A-CAP, see the A-CAP User Manual.

We welcome your feedback on this project, which is currently in active development. If you have questions, comments or suggestions, please contact the A-CAP Team. A-CAP is developed using MapServer, an open source development environment for building spatially-enabled Internet applications.