Geologic Publications for Mount Rainier

Frequent eruptions of Mount Rainier over the last ~2,600 years

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Author(s): Thomas W. Sisson, James W. Vallance

Category: PUBLICATION
Document Type:
Publisher: Bulletin of Volcanology
Published Year: 2009
Volume: 71
Number: 6
Pages: 595 to 618
DOI Identifier: 10.1007/s00445-008-0245-7
ISBN Identifier:
Keywords: Mount Rainier eruptions holocene tephra glass lahar hazards

Abstract:
Field, geochronologic, and geochemical evidence from proximal fine-grained tephras, and from limited exposures of Holocene lava flows and a small pyroclastic flow document ten–12 eruptions of Mount Rainier over the last 2,600 years, contrasting with previously published evidence for only 11–12 eruptions of the volcano for all of the Holocene. Except for the pumiceous subplinian C event of 2,200 cal year BP, the late-Holocene eruptions were weakly explosive, involving lava effusions and at least two block-and-ash pyroclastic flows. Eruptions were clustered from ∼2,600 to ∼2,200 cal year BP, an interval referred to as the Summerland eruptive period that includes the youngest lava effusion from the volcano. Thin, fine-grained tephras are the only known primary volcanic products from eruptions near 1,500 and 1,000 cal year BP, but these and earlier eruptions were penecontemporaneous with far-traveled lahars, probably created from newly erupted materials melting snow and glacial ice. The most recent magmatic eruption of Mount Rainier, documented geochemically, was the 1,000 cal year BP event. Products from a proposed eruption of Mount Rainier between AD 1820 and 1854 (X tephra of Mullineaux (US Geol Surv Bull 1326:1–83, 1974)) are redeposited C tephra, probably transported onto young moraines by snow avalanches, and do not record a nineteenth century eruption. We found no conclusive evidence for an eruption associated with the clay-rich Electron Mudflow of ∼500 cal year BP, and though rare, non-eruptive collapse of unstable edifice flanks remains as a potential hazard from Mount Rainier.

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In Text Citation:
Sisson and Vallance (2009) or (Sisson and Vallance, 2009)

References Citation:
Sisson, T.W. and J.W. Vallance, 2009, Frequent eruptions of Mount Rainier over the last ~2,600 years: Bulletin of Volcanology, Vol. 71, No. 6, pp. 595-618, doi: 10.1007/s00445-008-0245-7.