Radiocarbon dates from ice-edge ice-entombed tundra plants around the Orion and Serpens ice complexes, northern Baffin Island, Canada in 2018 and 2019

Radiocarbon dates on formerly ice-entombed tundra plants collected within 1 meter (m) of the current ice margin of rapidly receding ice caps on northern Baffin Island to test the concept of volcanic forcing on episodic ice cap expansion during the Common Era. The goal of this project is to examine the rate of onset of persistent Little Ice Age (LIA) cold by dating 50 new samples from current ice margins from ice complexes in Baffin Island, Canada, and comparing them to similar collections from 2005. If LIA ice expansion was abrupt and persistent then dates on the new plants should be about the same age as the 2005 samples, 200 to 500 m distant. Whereas if summers slowly cooled over decades-to-centuries through the late Holocene, then the new dates will be significantly older than their 2005 counterparts. Collectively, these data will provide the most robust testing of an abrupt onset of LIA cold and will be of interest to the sea ice and climate modeling communities.

对北巴芬岛快速退缩冰盖当前冰缘1米范围内采集的、曾被冰掩埋的苔原植物进行放射性碳年代测定，以验证公元时期火山强迫作用于冰盖间歇性扩张的概念。本项目的目标是通过测定加拿大巴芬岛冰体群当前冰缘的50个新样本年代，并与2005年的类似样本集对比，来研究持续小冰期（Little Ice Age，LIA）寒冷的开始速率。若小冰期冰盖扩张是突然且持续的，则这些新植物样本的年代应与相距200至500米的2005年样本年代大致相同；而若晚全新世期间夏季在数十年至数百年间缓慢降温，则新样本的年代将显著早于2005年的对应样本。总体而言，这些数据将为小冰期寒冷突然开始的假说提供最有力的验证，并将引起海冰和气候模拟领域的关注。