Browse by author
Lookup NU author(s): Dr Helen Mackay
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Volcanic ash layers preserved within the geologic record represent precise time markers that correlate disparate depositional environments and enable the investigation of synchronous and/or asynchronous behaviors in Earth system and archaeological sciences. However, it is generally assumed that only exceptionally powerful events, such as supereruptions (≥450 km3 of ejecta as dense-rock equivalent; recurrence interval of ∼105 yr), distribute ash broadly enough to have an impact on human society, or allow us to address geologic, climatic, and cultural questions on an intercontinental scale. Here we use geochemical, age, and morphological evidence to show that the Alaskan White River Ash (eastern lobe; A.D. 833–850) correlates to the “AD860B” ash (A.D. 846–848) found in Greenland and northern Europe. These occurrences represent the distribution of an ash over 7000 km, linking marine, terrestrial, and ice-core records. Our results indicate that tephra from more moderate-size eruptions, with recurrence intervals of ∼100 yr, can have substantially greater distributions than previously thought, with direct implications for volcanic dispersal studies, correlation of widely distributed proxy records, and volcanic hazard assessment.
Author(s): Jensen BJL, Pyne-O'Donnell S, Plunkett G, Froese DG, Hughes PDM, Sigl M, McConnell JR, Amesbury MJ, Blackwell PG, van den Bogaard C, Buck CE, Charman DJ, Clague JJ, Hall VA, Koch J, Mackay H, Mallon G, McColl L, Pilcher JR
Publication type: Article
Publication status: Published
Print publication date: 01/10/2014
Acceptance date: 21/07/2014
Date deposited: 15/12/2015
ISSN (print): 0091-7613
ISSN (electronic): 1943-2682
Publisher: Geological Society of America
Altmetrics provided by Altmetric