CO-OPS has been involved with tsunami warning and mitigation since the Coast Geodetic Survey started the Tsunami Warning System in 1948 to provide warnings to the Hawaiian Islands. After the December 2004 Indian Ocean tsunami, CO-OPS was tasked to coordinate with the NOAA Tsunami Warning Centers in upgrading existing stations with new Data Collection Platform (DCP) and communications technology and with expanding the tsunami warning capabilities of the NWLON. Work began in 2005 to upgrade 33 existing water level sand install 16 new stations from the Pacific Ocean to the Caribbean Sea by October 2006. As of September 2006, all 33 upgrades are complete, as well as 15 of the 16 new installations. As of October 2006 the NWLON consist of 196 long-term water level stations along all U.S. coasts, including the Great Lakes, Alaska, Hawaii, the Pacific Ocean Island Territories, Puerto Rico and the U.S. Virgin Islands. The National Geophysical Data Center (NGDC) serves as the archive center for this data and provides the historical data to users.