Wednesday, December 19, 2012

Corals show current sea levels are LOW, not high, by historical standards

A paper published today in Quaternary Research finds sea levels on the island of Curaçao [southern Caribbean] during the last interglacial were up to 9 meters higher than the present, and that during another interglacial period 400,000 years ago sea levels were up to 20 meters higher than the present. According to the paper, these significantly higher sea levels during prior interglacials "require major ice sheet loss from Greenland and Antarctica." The authors determine sea levels by dating fossilized reefs that are presently located high above current sea levels [photo below]. The paper also shows sea levels in the Red Sea were up to ~8 meters higher than the present within the past 5,000 years of the current interglacial, and up to ~12 meters higher than the present during the last interglacial. This and many other papers debunk claims by climate alarmists that recent sea level rise is unprecedented, unnatural, or accelerated.
Sea-level history of past interglacial periods from uranium-series dating of corals, Curaçao, Leeward Antilles islands

By Daniel R. Muhsa et al.


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


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