Volcano–ice interactions precursory to the 2009 eruption of Redoubt Volcano, Alaska

Journal of Volcanology and Geothermal Research
By: , and 

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Abstract

In late summer of 2008, after nearly 20 years of quiescence, Redoubt Volcano began to show signs of abnormal heat flow in its summit crater. In the months that followed, the excess heat triggered melting and ablation of Redoubt's glaciers, beginning at the summit and propagating to lower elevations as the unrest accelerated. A variety of morphological changes were observed, including the creation of ice cauldrons, areas of wide-spread subsidence, punctures in the ice carved out by steam, and deposition from debris flows. In this paper, we use visual observations, satellite data, and a high resolution digital elevation model of the volcanic edifice to calculate ice loss at Redoubt as a function of time. Our aim is to establish from this time series a proxy for heat flow that can be compared to other data sets collected along the same time interval. Our study area consists of the Drift glacier, which flows from the summit crater down the volcano's north slope, and makes up about one quarter of Redoubt's total ice volume of ~ 4 km3. The upper part of the Drift glacier covers the area of recent volcanism, making this part of ice mass most susceptible to the effect of volcanic heating. Moreover, melt water and other flows are channeled down the Drift glacier drainage by topography, leaving the remainder of Redoubt's ice mantle relatively unaffected. The rate of ice loss averaged around 0.1 m3/s over the last four months of 2008, accelerated to over twenty times this value by February 2009, and peaked at greater than 22 m3/s, just prior to the first major explosion on March 22, 2009. We estimate a cumulative ice loss over this period of about 35 million cubic meters (M m3).

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Volcano–ice interactions precursory to the 2009 eruption of Redoubt Volcano, Alaska
Series title Journal of Volcanology and Geothermal Research
DOI 10.1016/j.jvolgeores.2012.10.008
Volume 259
Year Published 2013
Language English
Publisher Elsevier
Contributing office(s) Volcano Science Center, Volcano Hazards Program
Description 16 p.
First page 373
Last page 388
Country United States
State Alaska
Other Geospatial Redoubt Volcano