Iceberg Discharges into the North Atlantic on Millennial Time Scales During the Last Glaciation

• Published in: Science
• Main Authors: Bond, Gerard C., Lotti, Rusty
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1995
• Subjects: Greenland; Dansgaard-Oeschger events; Greenland ice cores; Ice Sheet; North Atlantic
• Online Access: http://dx.doi.org/10.1126/science.267.5200.1005; https://www.science.org/doi/pdf/10.1126/science.267.5200.1005

High-resolution studies of North Atlantic deep sea cores demonstrate that prominent increases in iceberg calving recurred at intervals of 2000 to 3000 years, much more frequently than the 7000- to 10,000-year pacing of massive ice discharges associated with Heinrich events. The calving cycles correlate with warm-cold oscillations, called Dansgaard-Oeschger events, in Greenland ice cores. Each cycle records synchronous discharges of ice from different sources, and the cycles are decoupled from sea-surface temperatures. These findings point to a mechanism operating within the atmosphere that caused rapid oscillations in air temperatures above Greenland and in calving from more than one ice sheet.