The Antarctic ice sheet could be less stable than researchers previously believed.

Researchers looked at dramatic iceberg calving that took place between 9,000 and 19,000 years ago, a University of Hawaii at Manoa news release reported.

To make these findings researchers looked at "long deep sea sediment cores" taken from the Falkland Islands and the Antarctic Peninsula, the news release reported.

The findings suggest the Antarctic ice sheet is extremely unstable, and can abruptly change the climate and contribute to dramatic sea level rise.  

"One of the iceberg events in our data that is of particular interest took place 14,600 years ago and coincided with a huge ice-sheet melt, the famous Meltwater Pulse 1A, which according to previous studies led to a global sea level rise of about 4 meters within 100 years," lead author of the study, Michael Weber at the University of Cologne in Germany, said in the news release.

"This is the first direct evidence that instabilities of the Antarctic ice sheet caused rapid sea level rise during the last glacial termination," co-author Peter Clark, professor at Oregon State University, said in the news release.

In order to determine what caused such a traumatic Antarctic ice sheet collapse in the past the researchers conducted a number of modeling tests.

"An unusually strong flow of warm water towards Antarctica may have triggered these events. Our model experiments reveal further that the associated melting in turn increased the warm water flow, thus providing a positive feedback. This is a perfect recipe for rapid sea level rise," co-author Axel Timmermann, professor at the International Pacific Research Center of the University of Hawaii, said in the news release reported.

The study suggests the ice sheet experienced rapid changes in a time of transition from glacial to interglacial time.

"Our paleo data of abrupt ice-sheet instabilities provide an important benchmark against which future projections of human-induced changes in Antarctic ice volume and global sea level can be evaluated," Gerrit Lohmann, professor at the Alfred Wegener Institute, Bremerhaven, Germany, said in the news release.