Their approach improves sea-level reconstructions using coral ages and indicates that past sea level changes have been too frequent to be explained solely by orbital changes.
Reef corals are commonly used to reconstruct changes in sea level over time because they grow near the sea surface.
They also compared their data with salinity records from the Red Sea and found similar agreement, further verifying their model.
The team’s findings raise questions about the conditions required for the growth of ice sheets and the causes of rapid changes in sea level.
In archaeology, dating techniques fall into two broad categories: chronometric (sometimes called “absolute”) and relative.
Chronometric dating techniques produce a specific chronological date or date range for some event in the past. Relative dating techniques, on the other hand, provide only the relative order in which events took place.
However, the stratigraphic position alone cannot tell us the exact date.April 15, 2005 Corals from Papua New Guinea and Barbados indicate that changes in sea level, one of the key indexes for global climate change, may have been more frequent in the past than previously thought, according to a report in today’s issue of Science.Researchers from the Woods Hole Oceanographic Institution (WHOI) and Columbia University developed a new set of dating equations to determine the ages of corals from the Pacific and Atlantic Oceans to help resolve a longstanding question about the influence of Earth’s orbital variations on sea-level rise in the past.Because rainfall patterns vary annually, any given set of tree ring patterns in a region will form a relatively distinct pattern, identifiable with a particular set of years.By comparing the pattern of tree rings in trees whose lifespans partially overlap, these patterns can be extended back in time.
“We’ve discovered that corals behave as a two-box system.