Earlier this year, British soul singer Adele surprised just about everyone when her sophomore album, '21,' debuted atop the Billboard 200 album chart with an astounding 352,000 copies sold -- the biggest debut of any album this year. This week, '21' claims another title: first album of 2011 to go platinum.

According to Billboard, Adele topples Britney Spears' 'Femme Fatale' to reclaim the pole position on this week's album chart, moving 88,000 more copies and pushing her total domestic sales to 1.03 million. The year's second-biggest album, Mumford & Sons' 'Sigh No More,' is a distant second, having sold 645,000 copies.

The popularity of '21' can mostly be attributed to the success of its long-simmering lead single 'Rolling In The Deep,' which the singer-songwriter has described as a "dark bluesy gospel disco tune." Last week, after a slow climb up the charts, the song leapt from No. 17 to No. 10 to become Adele's first U.S. top ten hit. It remains at No. 10 on this week's chart.