Friday, 31 August 2007
5.PS-127
The Onset and Role of the Antarctic Circumpolar Current
Peter F. Barker, Threshers Barn, Whitcott Keysett, Clun, SY7 8QE, United Kingdom, Carlota Escutia, Instituto Anadaluz de Ciencias de la Tierra, Fuentenueva s/n, Granada, Spain, Gabe Filippelli, Indiana Univ. - Purdue, Purdue, 46202, Fabio Florindo, Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata, 605, Rome, I-00143, Italy, Satoshi Funakawa, Utsunomiya Univ., Utsunomiya, Japan, and Ellen Thomas, Yale Univ., New Haven, 06511.
A causal relationship between onsets of the Antarctic Circumpolar Current (ACC) and of Antarctic glaciation, as hypothesised 30 years ago, can no longer be supported. New data have changed perceptions of the ACC, other causal mechanisms for glaciation have arisen, some geological indicators of ACC action are now discounted and a wide range of ACC onset times (middle Eocene to late Miocene) has been proposed. Over the same period, the onset of stable Antarctic glaciation has become much better known. Here we describe these changes and put forward a plan for determining the time of ACC onset, that could also greatly assist in understanding its role in climate change.