A type of extraterrestrial hazard caused by solar wind shockwaves that temporarily disturb the Earth's magnetosphere. Geomagnetic storms can disrupt power grids, spacecraft operations, and satellite communications
The International Disaster Database (EM-DAT), The EM-DAT Glossary, Centre for Research on the Epidemiology of Disasters (CRED), School of Public Health, Universit catholique de Louvain, Brussels, Belgium 2009. http://www.emdat.be/glossary/9, (ND/ Gen - Brit) {855}