The 70 finalists in Smithsonian.com's 13th annual photography competition have been announced. The contest attracted more than 46,000 submissions from photographers in 168 countries and territories. The judges have chosen ten finalists in each of the seven categories: Natural World, The American Experience, Travel, People, Altered, Mobile, and Sustainable Travel.

You can help choose the winner of one of the awards. Readers are invited to vote for a special Readers' Choice Award. Polling will remain open until 21 March, and the Grand Prize, Readers' Choice, and seven category winners will be announced on 22 March. In this gallery, IBTimes UK publishes a selection of the finalists; see all 70 and vote for your favourite here.