Productivity modes in the Mediterranean Sea during Dansgaard-Oeschger (20,000-70,000 yr ago) oscillations

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doi: 10.1016/j.palaeo.2013.09.023
Author(s): Incarbona, Alessandro; Sprovieri, Mario; Di Stefano, Agata; Di Stefano, Enrico; Salvagio Manta, Daniela; Pelosi, Nicola; Ribera d'Alcala, Maurizio; Sprovieri, Rodolfo; Ziveri, Patrizia
Author Affiliation(s): Primary:
Universita degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Palermo, Italy
Other:
Consiglio Nazionale delle Ricerche, Italy
Universita di Catania, Italy
Laboratorio di Oceanografia Biologica, Italy
Universitat Autònoma de Barcelona, Spain
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Vol.392, p.128-137. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 90 refs.; illus., incl. charts, 2 tables, sketch map
Summary: The study of planktonic organisms during abrupt climatic variations of the last glacial period (Dansgaard-Oeschger oscillations, D-O) may reveal important insights on climatic, oceanographic and biological interactions. Here we present planktic foraminifera and coccolithophore data collected at the Ocean Drilling Program Site 963 (Sicily Channel), with a mean sampling resolution of respectively 43.5 and 98.9 yr, over the interval between 70,000 and 20,000 yr ago. The paleoenvironmental reconstruction suggests that three different scenarios can be seen across each D-O cycle: 1. oligotrophic surface water and a deep thermocline for the early Interstadials; 2. a Deep Chlorophyll Maximum and coccolithophore winter/spring blooming in the late Interstadials; 3. reduced productivity together with the shallowing of the nutricline depth during Stadials and Heinrich events. The unique mode of productivity dynamics is corroborated by comparing our paleoecological results with those published from high-resolution cores in the Alboran Sea clearly indicating reduced trophic levels during Stadials and Heinrich events. Finally, we argue that the density contrast between the Atlantic water inflow and subsurface water may have affected productivity dynamics in such a large area. The strong vertical density gradient may have hampered the vertical convection of the water column, producing a negative effect on biological productivity, especially during Stadial phases. Abstract Copyright (2013) Elsevier, B.V.
Year of Publication: 2013
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Alboran Sea; Algae; Assemblages; Cenozoic; Chlorophyll; Coccolithophoraceae; Dansgaard-Oeschger cycles; East Mediterranean; Foraminifera; Heinrich events; Invertebrata; Isotope ratios; Isotopes; Leg 160; Leg 161; Marine environment; Mediterranean Sea; Microfossils; O-18/O-16; ODP Site 963; ODP Site 977; Ocean Drilling Program; Organic compounds; Oscillations; Oxygen; Paleo-oceanography; Paleoecology; Pigments; Planktonic taxa; Plantae; Pleistocene; Porphyrins; Productivity; Protista; Quaternary; Seasonal variations; Sicily Channel; Stable isotopes; Strait of Sicily; Upper Pleistocene; West Mediterranean
Coordinates: N360154 N360154 W0015719 W0015719
N370202 N370202 E0131046 E0131046
Record ID: 2014016551
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands