Details

Autor(en) / Beteiligte

• Velay‐Vitow, Jesse
• Richard Peltier, W.

Titel

Out of the Ice Age: Megatides of the Arctic Ocean and the Bølling‐Ållerød, Younger Dryas Transition

Ist Teil von

• Geophysical research letters, 2020-12, Vol.47 (23), p.n/a

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Wiley Online Library - Journals

Beschreibungen/Notizen

• The most recent deglaciation of the Northern Hemisphere ice sheets began slowly subsequent to the Last Glacial Maximum (LGM) but was soon thereafter marked by a series of extremely rapid climate events, namely, Heinrich Event 1 (H1), the Bølling‐Ållerød (B‐A), and the Younger Dryas (YD). We show that a tidally forced marine ice stream instability mechanism, recently implicated as responsible for H1, may also have created the conditions required for the occurrence of the YD. Strong buoyancy forcing acting at the point of entry of the Amundsen Gulf Ice Stream (AGIS) into the Arctic Ocean would have destabilized the ice stream leading to its elimination. This buoyancy forcing was initially provided by the intense polar warming associated with the B‐A acting in conjunction with the moderately high‐amplitude tides that had existed since LGM. This initial destabilization led to a highly significant amplification of the tidal egime and thus AGIS destruction. Plain Language Summary It has been recently shown through detailed analysis that high‐amplitude tides may have been responsible for triggering Heinrich Event 1. We show that the same mechanism was most probably also involved in the deglaciation of the Amundsen Gulf ice stream. This ice stream existed in the channel that is now filled by the modern Mackenzie River which empties into the Arctic Ocean. This is the route by which the freshwater outflow that caused the Younger Dryas later entered into the Arctic Ocean. Key Points The Arctic Ocean was megatidal from the LGM to the beginning of the Bølling‐Ållerød Extremely high tides are predicted to have occurred in the Amundsen Gulf, potentially destabilizing the ice stream which existed there This instability cleared the channel through which the freshwater outflow that caused the YD later occurred