International scientists have shown that a dramatic sea-level rise occurred at the onset of the first warm period of the last deglaciation, known as the Blling warming, approximately 14,600 years ago. This event, referred to as Melt-Water Pulse 1A (MWP-1A), corresponds to a rapid collapse of massive ice sheets 14,600 years ago and resulted in global sea-level rise of ~14 m. These findings are published in the 29 March 2012 issue of the journal Nature (Volume 483, Issue 7391).
Collaboration between CEREGE (UMR Aix-Marseille Univ. - CNRS - IRD - College de France) and the Universities of Oxford and Tokyo, allowed an international science team to publish on research stemming from the Tahiti Sea-Level Expedition 310 of the Integrated Ocean Drilling Program (IODP). The Tahiti Sea-Level Expedition was carried out in 2005 by the European Consortium for Ocean Research Drilling (ECORD) and the ECORD Science Operator (ESO) on behalf of IODP.
Using U-Th dating of coral samples obtained from cores drilled in the Tahiti coral reefs, the researchers were able to reconstruct sea-level rise over the last deglaciation. Coral is extremely sensitive to sea-level changes and fossilized corals are therefore an excellent indicator for sea-level changes over time.
"Corals are outstanding archives to reconstruct past sea-level changes as they can be dated to within plus or minus 30 years stretching back thousands of years. Moreover, Tahitian reefs are ideally located to reconstruct the deglacial sea-level rise and to constrain short-term events that are thought to have punctuated the period between the Last Glacial Maximum and the present days. Tahiti is located at a sufficiently considerable distance from the major former ice sheets to give us close to the average of sea levels across the globe, as a non-volcanic island it is also subsiding into the ocean at a steady pace that we can easily adjust for." Pierre Deschamps, first author based at CERE
|Contact: Miyuki Otomo|
Integrated Ocean Drilling Program Management International