Top graph shows sea levels relative to the present during 3 prior interglacials. Bottom graph shows the Red Sea levels for comparison. |
Fossilized reefs [shown by dotted lines] formed when sea levels were much higher than the present. |
Sea-level history of past interglacial periods from uranium-series dating of corals, Curaçao, Leeward Antilles islands
- a U.S. Geological Survey, MS 980, Box 25046, Federal Center, Denver, CO 80225, USA
- b Australian Research Council Centre of Excellence for Coral Reef Studies and School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
Abstract
Curaçao has reef terraces with the potential to provide sea-level histories of interglacial periods. Ages of the Hato (upper) unit of the “Lower Terrace” indicate that this reef dates to the last interglacial period, Marine Isotope Stage (MIS) 5.5. On Curaçao, this high sea stand lasted at least 8000 yr (~ 126 to ~ 118 ka). Elevations and age of this reef show that late Quaternary uplift rates on Curaçao are low, 0.026–0.054 m/ka, consistent with its tectonic setting. Ages of ~ 200 ka for corals from the older Cortalein unit of the Lower Terrace correlate this reef to MIS 7, with paleo-sea level estimates ranging from − 3.3 m to + 2.3 m. The estimates are in agreement with those for MIS 7 made from other localities and indicate that the penultimate interglacial period was a time of significant warmth, on a par with the present interglacial period. The ~ 400 ka (MIS 11) Middle Terrace I on Curaçao, dated by others, may have formed from a paleo-sea level of + 8.3 to + 10.0 m, or (less likely) + 17 m to + 20 m. The lower estimates are conservative compared to previous studies, but still require major ice sheet loss from Greenland and Antarctica
.
.
Can one conclude that the land itself has not risen and fallen in this time period?
ReplyDeleteAccording to the paper:
Delete"Elevations and age of this reef show that late Quaternary uplift rates on Curaçao are low, 0.026–0.054 m/ka, consistent with its tectonic setting."
I'm sure the authors take this into consideration to determine the sea levels
How can they track the rising/sinking of the reef over time?
DeleteThey've only just starting to be able to do this with satellites.
http://en.wikipedia.org/wiki/Post-glacial_rebound
Deletehttp://www.princeton.edu/geosciences/people/maloof/pdf/Kopp2009b.pdf
ReplyDeletehttp://www.google.com/gwt/x?source=reader&u=http://www.washingtontimes.com/news/2012/dec/17/sea-level-rise-data-based-on-shoddy-science/print/%23ixzz2JHQed7qp&ei=9ZAGUamuA6qGkgKf-oGIDg&wsc=pb&ct=pg1&whp=30
ReplyDelete