Rapid thinning of Pine Island Glacier in the early Holocene

Pine Island Glacier, a major outlet of the West Antarctic Ice Sheet, has been undergoing rapid thinning and retreat for the past two decades. Here we demonstrate, using glacial-geological and geochronological data, that Pine Island Glacier also experienced rapid thinning during the early Holocene, around 8,000 years ago. Cosmogenic 10Be concentrations in glacially-transported rocks show that this thinning was sustained for decades to centuries at an average rate of more than 100 cm yr−1, comparable to contemporary thinning rates. The most likely mechanism was a reduction in ice shelf buttressing. Our findings reveal that Pine Island Glacier has experienced rapid thinning at least once in the past, and that, once set in motion, rapid ice sheet changes in this region can persist for centuries.