Comment on “Mixed-Layer Deepening During Heinrich Events:
foraminera from marine sediments and concluded that Heinrich events (massive iceberg discharges into the North Atlantic Ocean) caused upper water masses to deepen. We question the robustness of this interpretation and argue that a strongly stratified mixed layer characterized by dense sea-ice cover...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.663.7008 http://www.pcsn.ca/pubs_2008/Hillaire-Marcel+and+DeVernal,+Comment+on+Mixed+Layer+Deepening+during+H1,+Science,+2008.pdf |
| Summary: | foraminera from marine sediments and concluded that Heinrich events (massive iceberg discharges into the North Atlantic Ocean) caused upper water masses to deepen. We question the robustness of this interpretation and argue that a strongly stratified mixed layer characterized by dense sea-ice cover and production of oxygen-18–depleted brines likely prevailed during such events. Rashid and Boyle (1) argued that substan-tial mixed-layer deepening occurred dur-ing Heinrich events (HEs) in the North Atlantic Ocean, citing similar oxygen isotope var-iations inmixed-layer – and thermocline-dwelling planktonic foraminifera during HEs 0, 1, and 4 as evidence. This hypothesis was already put forth by Hillaire-Marcel and Bilodeau (2) based on comparative d18O analysis of two of the plank-tonicic foraminifers studied in (1)—Globigerina bulloides, an epipelagic species, and Neoglobo-quadrina pachyderma sinistral (s), a left-coiling |
|---|