Diatom ecological response to deposition of the 833-850 CE White River Ash (east lobe) ashfall in a small subarctic Canadian lake

• Published in: PeerJ
• Main Authors: Hutchinson, S.J. (Scott J.), Hamilton, P.B. (Paul B.), Patterson, T. (Tim), Galloway, J.M. (Jennifer M.), Nasser, N.A. (Nawaf A.), Spence, C. (Christopher), Falck, H. (Hendrik)
• Format: Other/Unknown Material
• Language: English
• Published: 2019
• Subjects: Aquatic ecosystems; Diatoms; Lake; Palaeolimnology; Tephra; Volcanic eruption; Northwest Territories; Yellowknife; Canada; Subarctic; Alaska
• Online Access: https://ir.library.carleton.ca/pub/23663; https://doi.org/10.7717/peerj.6269

A <5 mm thick volcanic ashfall layer associated with the White River Ash (east lobe [WRAe]) originating from the eruption of Mount Churchill, Alaska (833-850 CE; 1,117-1,100 cal BP) was observed in two freeze cores obtained from Pocket Lake (62.5090◦N, −114.3719◦W), a small subarctic lake located within the city limits of Yellowknife, Northwest Territories, Canada. Here we analyze changes in diatom assemblages to assess impact of tephra deposition on the aquatic biota of a subarctic lake. In a well-dated core constrained by 8 radiocarbon dates, diatom counts were carried out at 1-mm intervals through an interval spanning 1 cm above and below the tephra layer with each 1 mm sub-sample represented about 2 years of depo