Productivity cycles of 200–300 years in the Antarctic Peninsula region: Understanding linkages among the sun, atmosphere, oceans, sea ice, and biota

Research Article| December 01, 1996 Productivity cycles of 200–300 years in the Antarctic Peninsula region: Understanding linkages among the sun, atmosphere, oceans, sea ice, and biota Amy Leventer; Amy Leventer 1Limnological Research Center, University of Minnesota, Minneapolis, Minnesota 55455 Search for other works by this author on: GSW Google Scholar Eugene W. Domack; Eugene W. Domack 2Department of Geology, Hamilton College, Clinton, New York 13323 Search for other works by this author on: GSW Google Scholar Scott E. Ishman; Scott E. Ishman 3U.S. Geological Survey, Reston, Virginia 22092 Search for other works by this author on: GSW Google Scholar Stefanie Brachfeld; Stefanie Brachfeld 4Institute for Rock Magnetism, University of Minnesota, Minneapolis, Minnesota 55455 Search for other works by this author on: GSW Google Scholar Charles E. McClennen; Charles E. McClennen 5Department of Geology, Colgate University, Hamilton, New York 13346 Search for other works by this author on: GSW Google Scholar Patricia Manley Patricia Manley 6Department of Geology, Middlebury College, Middlebury, Vermont 05753 Search for other works by this author on: GSW Google Scholar Author and Article Information Amy Leventer 1Limnological Research Center, University of Minnesota, Minneapolis, Minnesota 55455 Eugene W. Domack 2Department of Geology, Hamilton College, Clinton, New York 13323 Scott E. Ishman 3U.S. Geological Survey, Reston, Virginia 22092 Stefanie Brachfeld 4Institute for Rock Magnetism, University of Minnesota, Minneapolis, Minnesota 55455 Charles E. McClennen 5Department of Geology, Colgate University, Hamilton, New York 13346 Patricia Manley 6Department of Geology, Middlebury College, Middlebury, Vermont 05753 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1996) 108 (12): 1626–1644. https://doi.org/10.1130/0016-7606(1996)1082.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Amy Leventer, Eugene W. Domack, Scott E. Ishman, Stefanie Brachfeld, Charles E. McClennen, Patricia Manley; Productivity cycles of 200–300 years in the Antarctic Peninsula region: Understanding linkages among the sun, atmosphere, oceans, sea ice, and biota. GSA Bulletin 1996;; 108 (12): 1626–1644. doi: https://doi.org/10.1130/0016-7606(1996)1082.3.CO;2 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 SocietyGSA Bulletin Search Advanced Search Abstract Compared to the rest of the world's oceans, high-resolution late Holocene paleoclimatic data from the Southern Ocean are still rare. We present a multiproxy record from a sediment core retrieved from a deep basin on the western side of the Antarctic Peninsula that reveals a dramatic perspective on paleoclimatic changes over the past 3700 yr. Analyses completed include measurement of magnetic susceptibility and granulometry, bed thickness, particle size, percent organic carbon, bulk density, and microscopic evaluation of diatom and benthic foraminiferal assemblages and abundances. Downcore variability of these parameters demonstrates the significance of both short-term cycles, which recur approximately every 200 yr, and longer term events (≈2500 yr cycles) that are most likely related to global climatic fluctuations.In the upper 600 cm of the core, lower values of magnetic susceptibility (MS) are correlated with lower bulk density, the presence of thinly laminated units, specific diatom assemblages, and generally higher total organic carbon content. Below 600 cm, magnetic susceptibility is uniformly low, though variability in other parameters continues. The magnetic susceptibility signal is controlled primarily by dilution of ferromagnetic phases with biosiliceous material. This signal may be enhanced further by dissolution of magnetite in the magnetic susceptibility lows (high total organic carbon). The role of variable primary productivity and its relationship to paleoclimate is assessed through the diatom data. In particular, magnetic susceptibility lows are characterized by higher than normal abundances of Chaetoceros resting spores. Corethron criophilum and/or Rhizosolenia spp. also are found, as is a higher ratio of the most common species of Fragilariopsis versus species of Thalassiosira. These assemblages are indicative of periods of high primary productivity driven by the presence of a meltwater stabilized water column. The 200 yr cyclicity noted in other paleoclimatic records around the world suggests a global forcing mechanism, possibly solar variability. In addition to the cyclic changes in productivity, overall elevated productivity is noted below 600 cm, or prior to ca. 2500 yr B.P. This increased productivity may represent the tail end of a Holocene climatic optimum, which is widely recognized in other parts of the world, but as yet is poorly documented in Antarctica. This content is PDF only. Please click on the PDF icon to access. 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