Direct Determination of the Timing of Sea Level Change During Termination II

An outcrop within the last interglacial terrace on Barbados contains corals that grew during the penultimate deglaciation, or Termination II. We used combined 230Th and231Pa dating to determine that they grew 135.8 ± 0.8 thousand years ago, indicating that sea level was 18 ± 3 meters below present sea level at the time. This suggests that sea level had risen to within 20% of its peak last-interglacial value by 136 thousand years ago, in conflict with Milankovitch theory predictions. Orbital forcing may have played a role in the deglaciation, as may have isostatic adjustments due to large ice sheets. Other corals in the same outcrop grew during oxygen isotope (δ18O) substage 6e, indicating that sea level was 38 ± 5 meters below present sea level, about 168.0 thousand years ago. When compared to the δ18O signal in the benthic V19-30/V19-28 record at that time, the coral data extend to the previous glacial cycle the conclusion that deep-water temperatures were colder during glacial periods.

[1]  T. Herbert,et al.  Collapse of the California Current During Glacial Maxima Linked to Climate Change on Land , 2001, Science.

[2]  Eli Tziperman,et al.  Sea ice as the glacial cycles' climate switch: Role of seasonal and orbital forcing , 2000 .

[3]  N. Shackleton,et al.  The 100,000-year ice-Age cycle identified and found to lag temperature, carbon dioxide, and orbital eccentricity , 2000, Science.

[4]  D. Lea,et al.  Climate impact of late quaternary equatorial pacific sea surface temperature variations , 2000, Science.

[5]  Hai Cheng,et al.  The half-lives of uranium-234 and thorium-230 , 2000 .

[6]  M. McCulloch,et al.  The coral record of last interglacial sea levels and sea surface temperatures , 2000 .

[7]  R. Muller,et al.  A Causality Problem for Milankovitch , 2000, Science.

[8]  G. Henderson,et al.  Evidence from U–Th dating against Northern Hemisphere forcing of the penultimate deglaciation , 2000, Nature.

[9]  J. Jouzel,et al.  Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica , 1999, Nature.

[10]  McCulloch,et al.  Rapid fluctuations in sea level recorded at huon peninsula during the penultimate deglaciation , 1999, Science.

[11]  Wallace S. Broecker,et al.  The sequence of events surrounding Termination II and their implications for the cause of glacial‐interglacial CO2 changes , 1998 .

[12]  J. M. Landwehr,et al.  Duration and Structure of the Past Four Interglaciations , 1997, Quaternary Research.

[13]  Edwards,et al.  Protactinium-231 Dating of Carbonates by Thermal Ionization Mass Spectrometry: Implications for Quaternary Climate Change , 1997, Science.

[14]  J. Pandolfi,et al.  Reconciliation of late Quaternary sea levels derived from coral terraces at Huon Peninsula with deep sea oxygen isotope records , 1996 .

[15]  R. Lawrence Edwards,et al.  The Timing of High Sea Levels Over the Past 200,000 Years , 1994, Science.

[16]  G. Wasserburg,et al.  TIMS U-series dating and stable isotopes of the last interglacial event in Papua New Guinea , 1993 .

[17]  Tyler B. Coplen,et al.  Continuous 500,000-Year Climate Record from Vein Calcite in Devils Hole, Nevada , 1992, Science.

[18]  J. M. Landwehr,et al.  Mass-Spectrometric 230Th-234U-238U Dating of the Devils Hole Calcite Vein , 1992, Science.

[19]  R. G. Johnson.  Major Northern Hemisphere deglaciation caused by a moisture deficit 140 ka , 1991 .

[20]  F. Taylor,et al.  Late Quaternary folding of coral reef terraces, Barbados , 1991 .

[21]  R. Fairbanks.  A 17,000-year glacio-eustatic sea level record: influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation , 1989, Nature.

[22]  G. Wasserburg,et al.  Precise Timing of the Last Interglacial Period from Mass Spectrometric Determination of Thorium-230 in Corals , 1987, Science.

[23]  J. D. Hays,et al.  Age Dating and the Orbital Theory of the Ice Ages: Development of a High-Resolution 0 to 300,000-Year Chronostratigraphy , 1987, Quaternary Research.

[24]  G. Wasserburg,et al.  238U234U230Th232Th systematics and the precise measurement of time over the past 500,000 years , 1987 .

[25]  N. Shackleton,et al.  Oxygen isotopes and sea level , 1986, Nature.

[26]  W. Broecker,et al.  Uranium-series dating of the Pleistocene reef tracts of Barbados, West Indies , 1979 .

[27]  André Berger,et al.  Long-Term Variations of Caloric Insolation Resulting from the Earth's Orbital Elements , 1978, Quaternary Research.

[28]  W. Broecker,et al.  The Astronomical Theory of Climatic Change: Barbados Data , 1969, The Journal of Geology.