Mumford & Sons' new album notches the year's biggest debut

Mumford & Sons blew up the charts this week, debuting at No. 1 with "Babel."

The band's sophomore release sold a whopping 600,000 copies in its first week, according to Billboard, citing Nielsen SoundScan figures. It marks the biggest U.S. debut of any album this year.

To put that in perspective, this year's second highest debut - Justin Bieber's "Believe" album - sold 374,000 copies in its first week. "Babel" also had the second largest digital sales week with 420,000 downloads, second to only Lady Gaga's "Born This Way," which had 662,000 last year.

The English band's new release has gained traction on the Alternative airplay radio chart, already snagging four top 10 singles.

Mumford & Sons will be on tour in the U.K. and Australia through the end of the year.