Researchers from the University of Bristol (UK) reported the discovery of the causes of rapid sea-level rise during the two episodes that took place about 14 600 and 8200 years ago.
The simulation of climate and ice cover those distant times, Lauren Gregoire and his colleagues concluded that the chain of events led to the disintegration of the ice sheet that covered North America, into several parts. As a result of melting has accelerated and formed ice-free corridors.
Thick ice caps 3km occur in areas with heavy snowfall and high relief - for example, in the Rocky Mountains. Along with saddles, ie ice valleys between domes, they form ice sheets.
When the Ice Age came to an end, ice, of course, melted from the bottom up. Sooner or later he will get to these saddles, they began to sink and sink to the warmer altitudes where melted even more. As a result of 500 years of the saddle disappeared and left the dome.
Meltwater has led to a rapid rise in sea level in the first case - 9 m for 500 years, in the second - 2, 5 m in the same period. The model showed that up to half of this increase was the melting of the saddles, while the rest were given gradually tayavshie ice sheets of Antarctica and Europe.
The study is published in the journal Nature.