Revisiting the Timing of the Northern Lobe of the White River Ash Volcanic Event in Eastern Alaska and Western Yukon

ABSTRACT The northern lobe of the White River Ash (WRAn) is part of a bilobate distribution of tephras that originated from the Wrangell Volcanic Field near the border of Alaska, USA, and Yukon, Canada. It is distributed across northeastern Alaska and the northwestern portion of the Yukon. The timin...

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Bibliographic Details
Published in:Radiocarbon
Main Authors: Reuther, Joshua, Potter, Ben, Coffman, Sam, Smith, Holly, Bigelow, Nancy
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 2019
Subjects:
Online Access:http://dx.doi.org/10.1017/rdc.2019.110
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033822219001103
Description
Summary:ABSTRACT The northern lobe of the White River Ash (WRAn) is part of a bilobate distribution of tephras that originated from the Wrangell Volcanic Field near the border of Alaska, USA, and Yukon, Canada. It is distributed across northeastern Alaska and the northwestern portion of the Yukon. The timing of this eruption has seen little critical analysis relative to the younger and more extensive eastern lobe eruption of the White River Ash. We compiled 38 radiocarbon ( 14 C) dates from above and below the WRAn, and employed several statistical approaches to identify and eliminate or down-weight outliers, combine dates, and different Bayesian models, to provide a revised age estimate for the timing of the WRAn tephra deposition. Our results indicate that the most accurate modeled age estimate for the northern lobe of the White River Ash deposition is between 1689 and 1560 cal BP, with a mean and median of 1625 and 1623 cal BP, respectively. This age range is 90 to 200 years younger than previous age estimates.