The technical name is "fast-mode magnetohydrodynamical wave"?or "MHD wave" for short. The one observed by Solar Terrestrial Relations Observatory reared up about 100,000 km high, and raced outward at 250 km/s (560,000 mph) packing as much energy as 2400 megatons of TNT (1029 ergs).
http://science.nasa.gov/headlines/y2009/24nov_solartsunami.htm?list1326915