Mid-Holocene El Niño–Southern Oscillation (ENSO) attenuation revealed by individual foraminifera in eastern tropical Pacific sediments

Research Article| December 01, 2006 Mid-Holocene El Niño–Southern Oscillation (ENSO) attenuation revealed by individual foraminifera in eastern tropical Pacific sediments Athanasios Koutavas; Athanasios Koutavas 1Department of Engineering Science and Physics, College of Staten Island, The City University of New York, 2800 Victory Blvd., Staten Island, New York 10314, USA, and Lamont-Doherty Earth Observatory of Columbia University, 61 Rt. 9W, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar Peter B. deMenocal; Peter B. deMenocal 2Lamont-Doherty Earth Observatory of Columbia University, 61 Rt. 9W, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar George C. Olive; George C. Olive 3Columbia University, 2960 Broadway, New York, New York 10027, USA Search for other works by this author on: GSW Google Scholar Jean Lynch-Stieglitz Jean Lynch-Stieglitz 4School of Earth and Atmospheric Sciences, 311 Ferst Drive, Georgia Institute of Technology, Atlanta, Georgia 30332, USA Search for other works by this author on: GSW Google Scholar Geology (2006) 34 (12): 993–996. https://doi.org/10.1130/G22810A.1 Article history received: 25 Mar 2006 rev-recd: 16 Jun 2006 accepted: 20 Jun 2006 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Athanasios Koutavas, Peter B. deMenocal, George C. Olive, Jean Lynch-Stieglitz; Mid-Holocene El Niño–Southern Oscillation (ENSO) attenuation revealed by individual foraminifera in eastern tropical Pacific sediments. Geology 2006;; 34 (12): 993–996. doi: https://doi.org/10.1130/G22810A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Holocene reconstructions of the El Niño–Southern Oscillation (ENSO) provide valuable perspective on its recent evolution and can be important for assessing its future. Optimal assessment of past ENSO variability requires observations from its center of action in the eastern equatorial Pacific, but these are limited due to paucity of high-resolution paleoceanographic archives (e.g., corals). Here we use a new approach to quantify past ENSO variance based on the oxygen isotopic composition (δ18O) of individual foraminifera (Globigerinoides ruber) from deep-sea sediments in the ENSO source region. Individual G. ruber foraminifera behave as monthly recorders of sea-surface conditions, including ENSO extremes, circumventing the lack of annual resolution in the sediments. Intrapopulation δ18O distributions derived with this method from a core near the Galapagos Islands reveal mid-Holocene reductions in variance of 50%, requiring drastic attenuation of the ENSO amplitude. Furthermore, Mg/Ca thermometry indicates that mid- Holocene background conditions were accompanied by a stronger zonal temperature gradient that coincided with a northward- displaced Intertropical Convergence Zone (ITCZ). The results suggest that the position of the ITCZ is an important factor in the low-frequency modulation of ENSO and could influence its future evolution. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.