Increased ventilation of the Northern Indian Ocean during the last deglaciation

Abstract

This paper gives an overview of the deep-water ventilation studies carried out over the world oceans using radiocarbon. There is a consensus that aged water mass existing in the abyssal ocean during the last glacial, dissipated during the Heinrich Stadial 1 (HS1; 17.5-14.7 ka) and the Younger Dryas (YD; 12.9-11.7 Ka, cold event) and hence ventilation increased. The data from the Arabian Sea is in agreement with global records and shows a significant aging of intermediate waters during HS1 and to a lesser extent during the YD and also shows an outgassing of CO sub(2) centered on the early Bolling Allerod (B-A). Though several studies have been carried out in the Atlantic and Pacific, the Indian Ocean remains scantily studied. Hence it is extremely important to have sufficient data on the ventilation aspect from specific locations in the Indian Ocean chosen to be in the pathway of the deep water circulation branch directing southern sourced waters up north.