Mountain glacier fluctuations during the Lateglacial and Holocene on Clavering Island (northeastern Greenland) from 10 Be moraine dating
Résumé
Despite an increasing interest in Greenlandic mountain glaciers over recent decades, their evolution during theLateglacialandHolocenestillneedstobebetterconstrained.Herewepresent2510Becosmic-rayexposure(CRE)agesof boulders collected on moraines from three glaciers located on Clavering Island (northeastern Greenland). CREages span16.290.79to 0.370.05ka andrevealthree periodsof moraineformationduringthe Lateglacial,theEarlyand the Late Holocene. Data show a multi-modal distribution of the ages during the Lateglacial with exposure agesspanning from 16.290.79 to 12.311.3 ka. At least two glaciers experienced a greater expansion at the beginning ofthe Holocene than at the end of the Holocene, dated to 11.30.3 and 10.80.6 ka, respectively. At the end of theHolocene, glacial advances occurred during the Dark Ages Cold Period and during the Little Ice Age (LIA),synchronous with glacial advances documented in nearby lake sediments. This new CRE chronology highlights thatthe LIA extent is not the largest glacier advance in the Late Holocene in Clavering Island. This broadly correspondswithothermountainglaciersofwesternandnorthernGreenland,anddoesnotappeartoreflectnorthernhighlatitudesummer insolation that would suggest progressive temperature decrease, but instead mimics recent regionalcontinental temperature reconstructions that show a long term warming driven by different forcing.
Fichier principal
Mountain glacier fluctuations during the Lateglacial and Holocene on Clavering Island (northeastern Greenland) from 10Be moraine dating.pdf (285.15 Ko)
Télécharger le fichier