COPENHAGEN, DENMARK - APRIL 16:  Queen Margrethe of Denmark  waves to wellwishers from a carriage during celebrations marking her 70th birthday on April 16, 2010 in Copenhagen. Queen Margrethe of Denmark dealt with a few empty seats at her birthday concert on April 15, as Copenhagen airport was closed due to the cloud of volcanic ash sweeping across Europe. (Photo by Julien Hekimian/WireImage)