Martin, Pamela A.

Patton, Genna M.

Voelker, Antje H. L.

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2008 Fall Meeting          Search ResultsCite abstracts as Author(s) (2008), Title, Eos Trans. AGU,89(53), Fall Meet. Suppl., Abstract xxxxx-xxYour query was:pattonHR: 0800hAN: PP11A-1368TI: Mg/Ca Paleothermometry in the Central Gulf of Cadiz During Heinrich EventsAU: * Patton, G MEM: gpatton@uchicago.eduAF: University of Chicago, Department of Geophysical Sciences, 5734 S Ellis Ave, Chicago, IL 60637,United StatesAU: Martin, P AEM: pmartin@uchicago.eduAF: University of Chicago, Department of Geophysical Sciences, 5734 S Ellis Ave, Chicago, IL 60637,United StatesAU: Voelker, AEM: avoelker@pro.softhome.netAF: INETI (Future LNEG - Laboratorio Nacional de Energia e Geologia), Departamento de GeologiaMarinha, Estrada da Portela, Zambujal, Alfragide, 2721-866, PortugalAB: During the last glacial and deglacial period (16kya-46kya), the Iberian Margin experienced local seasurface  temperature  fluctuations  as  a  result  of  melting  icebergs  from catastrophic  calvings  of  theLaurentide Ice Sheet  (Heinrich Events).  Using Mg/Ca in species of  planktonic  foraminifera,  we arereconstructing temperature for Heinrich Events one (H1), four (H4) and five (H5) from core MD99 2339in the Gulf  of  Cadiz (35.88°N; 7.53°W, 1170m). Locally,  all  three of  these events are quite intenseshowing O-18 excursions of approximately 1.5 parts per mil. Low Mg/Ca values during the HeinrichEvents imply significant local and possibly regional cooling. For example, temperatures derived fromMg/Ca during H1 show a temperature oscillation of approximately 7°C between the start and end of theHeinrich Event. While this is a large temperature oscillation, it is of slightly smaller amplitude than the11°C swing implied by assemblage data for winters (Voelker et al.,  2006). By comparing a suite oftemperature  proxies  in  the  same  region  (Mg/Ca,  planktonic  foraminiferal  assemblage  data  andalkenones), we hope to better constrain the climate fluctuations during these time periods as well asgain insight into secondary environmental effects that complicate interpretation of the proxies strictly astemperature.  Mg/Ca  variations  through  an  entire  Heinrich  event  imply  that  temperatures  in  thissubtropical region are quite variable and highly dependent on the amount of subpolar waters advectedinto the Gulf.  Using multiple species of  foraminifera,  we are now attempting to construct  a verticaltemperature profile prior to, during and after the episode to get a better indication of the penetration ofcolder  temperatures  -  although  investigations  are  challenging  due  to  low  absolute  foraminiferalabundances surrounding Heinrich events. Looking at Cd/Ca, we also have new clues about nutrientchanges during these time periods, which we hope will lead to a more complete picture of the local andregional environment during Heinrich Events.DE: 4901 Abrupt/rapid climate change (1605)DE: 4926 GlacialDE: 4954 Sea surface temperatureSC: Paleoceanography and Paleoclimatology [PP]MN: 2008 Fall Meeting   New Search

Mg/Ca paleothermometry in the Central Gulf of Cadiz during Heinrich Events

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Mg/Ca paleothermometry in the Central Gulf of Cadiz during Heinrich Events

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