Reconstructing Modern and LGM Water Column Hydrography Using Stable Isotopes of Single Specimens of Multiple Planktic Foraminifera

Authors

J. S. Fehrenbacher, University of California, Davis
Howard J. Spero, University of California, Davis
L. Vetter, University of California, Davis
C. V. Davis, University of California, Davis
J. M. Griffin, University of California, Davis
B. L. Grimm, University of California, Davis
P. Kercher, University of California, Davis
M. Kostlan, University of California, Davis
Anthony J. Menicucci, University of California, DavisFollow
L. Santare, University of California, Davis
M. Wildgoose, University of California, Davis
J. Starnes, University of California, Davis
E. Wilbanks, University of California, Davis

Document Type

Presentation

Publication Date

2013

Abstract

Oxygen and carbon isotope data from planktic foraminifera play an important role in paleoceanographic reconstructions of temperature, salinity, and nutrients. Typically, such analyses are conducted using multiple shells of the same species. However, important habitat depth and seasonal information are lost in pooled shell analyses. In this study, we have analyzed the δ¹⁸O and δ¹³C of single specimens of different species of planktic foraminifera including G. ruber (pink & white var.), G. sacculifer, O. universa, G. siphonifera, S. dehiscens, G. conglobatus, G. menardii, N. dutertrei, P. obliquiloculata, G. truncatulinoides and G. tumida from a western Caribbean core (OPDP 999A) and eastern equatorial Pacific (EEP) core (TR163-19). We use the average species δ¹⁸O values to estimate mean depth habitats and, for comparison purposes, normalize each species δ18O values to the δ18O:temperature relationship of G. ruber/O. universa (Bemis et al., 1998; Thunell et al, 2000). In order to compare δ¹³CDIC through time and space, we develop δ¹³C ‘corrections’ to normalize the δ¹³CFORAM values to the modern δ¹³CDIC for each core site. We find that both δ¹⁸O and δ¹³C normalization for each species varies between sites and attribute this variation to water column differences in [CO32-] between the Caribbean and EEP. We explore employing these corrections through time by applying the modern corrections to LGM δ¹³C /δ¹⁸O data. This multispecies, individual shell analysis approach may provide a method to infer changes in upper water column δ¹⁸OSW and δ¹³CDIC gradients through time.

Was this content written or created while at USF?

No

Citation / Publisher Attribution

Presented at the 2013 AGU Fall Meeting in San Francisco, CA

Scholar Commons Citation

Fehrenbacher, J. S.; Spero, Howard J.; Vetter, L.; Davis, C. V.; Griffin, J. M.; Grimm, B. L.; Kercher, P.; Kostlan, M.; Menicucci, Anthony J.; Santare, L.; Wildgoose, M.; Starnes, J.; and Wilbanks, E., "Reconstructing Modern and LGM Water Column Hydrography Using Stable Isotopes of Single Specimens of Multiple Planktic Foraminifera" (2013). School of Geosciences Faculty and Staff Publications. 1792.
https://digitalcommons.usf.edu/geo_facpub/1792