Piva Stephen B, Barker Simon J, Iverson Nels A, Winton V Holly L, Bertler Nancy A N, Sigl Michael, Wilson Colin J N, Dunbar Nelia W, Kurbatov Andrei V, Carter Lionel, Charlier Bruce L A, Newnham Rewi M
School of Geography, Environment and Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, 6140, New Zealand.
New Mexico Bureau of Geology and Mineral Resources, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM, 87801, USA.
Sci Rep. 2023 Oct 9;13(1):16720. doi: 10.1038/s41598-023-42602-3.
Chemical anomalies in polar ice core records are frequently linked to volcanism; however, without the presence of (crypto)tephra particles, links to specific eruptions remain speculative. Correlating tephras yields estimates of eruption timing and potential source volcano, offers refinement of ice core chronologies, and provides insights into volcanic impacts. Here, we report on sparse rhyolitic glass shards detected in the Roosevelt Island Climate Evolution (RICE) ice core (West Antarctica), attributed to the 1.8 ka Taupō eruption (New Zealand)-one of the largest and most energetic Holocene eruptions globally. Six shards of a distinctive geochemical composition, identical within analytical uncertainties to proximal Taupō glass, are accompanied by a single shard indistinguishable from glass of the ~25.5 ka Ōruanui supereruption, also from Taupō volcano. This double fingerprint uniquely identifies the source volcano and helps link the shards to the climactic phase of the Taupō eruption. The englacial Taupō-derived glass shards coincide with a particle spike and conductivity anomaly at 278.84 m core depth, along with trachytic glass from a local Antarctic eruption of Mt. Melbourne. The assessed age of the sampled ice is 230 ± 19 CE (95% confidence), confirming that the published radiocarbon wiggle-match date of 232 ± 10 CE (2 SD) for the Taupō eruption is robust.
极地冰芯记录中的化学异常现象常常与火山活动有关；然而，若没有（隐伏）火山灰颗粒的存在，与特定火山喷发的联系仍具有推测性。将火山灰进行对比可得出火山喷发时间和潜在源火山的估计值，有助于完善冰芯年代学，并深入了解火山活动的影响。在此，我们报告在罗斯福岛气候演化（RICE）冰芯（南极西部）中检测到的稀少流纹岩玻璃碎片，它们归因于1.8 ka陶波火山喷发（新西兰）——全球最大且能量最强的全新世火山喷发之一。六个具有独特地球化学组成的碎片，在分析误差范围内与陶波火山附近的玻璃相同，同时还有一个碎片与同样来自陶波火山的约25.5 ka奥鲁阿努伊超级火山喷发的玻璃无法区分。这种双重指纹独特地确定了源火山，并有助于将这些碎片与陶波火山喷发的气候阶段联系起来。冰内源自陶波火山的玻璃碎片与冰芯深度278.84 m处的颗粒峰值和电导率异常相吻合，同时还有来自南极墨尔本山当地火山喷发的粗面岩玻璃。所采集冰层的评估年龄为公元230±19年（95%置信度），证实了已发表的陶波火山喷发的放射性碳摆动匹配日期公元232±10年（2标准差）是可靠的。
