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Ventilation changes in intermediate water on millennial time scales in the SE Nordic seas, 65‐14 kyr BP
Author(s) -
Rasmussen Tine L.,
Thomsen Erik
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl036563
Subject(s) - halocline , stadial , glacial period , geology , oceanography , outflow , stratification (seeds) , climatology , environmental science , salinity , paleontology , seed dormancy , botany , germination , dormancy , biology
A glacial epibenthic δ 13 C record from 773 m water depth in the SE Nordic seas reveals moderate, but distinct changes in the ventilation ∼65,000−14,000 years ago. The Last Glacial Maximum, the warm interstadials, and the shorter stadials are characterized by high δ 13 C values indicating well‐ventilated intermediate water masses in the Nordic seas. Decreasing δ 13 C values during the cold Heinrich events signify a reduction in intermediate water ventilation. We attribute the reduction to the development of a halocline causing a stop in convection and outflow from the Nordic seas. The well‐ventilated outflow water is replaced by warmer Atlantic water, which due to the stratification is isolated from the atmosphere. Its initial high δ 13 C values are reduced due to 'ageing'. We ascribe the lack of response in the subsurface Atlantic Water during the stadials to the smaller geographical extent of these events as compared to the Heinrich events.