Preliminary slope-stability analysis of Augustine Volcano: Chapter 14 in The 2006 eruption of Augustine Volcano, Alaska

Professional Paper 1769- 14
By: , and 
Edited by: John A. PowerMichelle L. Coombs, and Jeffrey T. Freymueller



Augustine Volcano has been a prolific producer of large debris avalanches during the Holocene. Originating as landslides from the steep upper edifice, these avalanches typically slide into the surrounding ocean. At least one debris avalanche that occurred in 1883 during an eruption initiated a far-traveled tsunami. The possible occurrence of another edifice collapse and ensuing tsunami was a concern during the 2006 eruption of Augustine. To aid in hazard assessments, we have evaluated the slope stability of Augustine's edifice, using a quasi-three-dimensional, geotechnically based slope-stability model implemented in the computer program SCOOPS. We analyzed the effects of topography, variations in rock strength, and earthquake-induced strong ground motion on the relative stability of millions of potential large (>0.1 km3 volume) slope failures throughout the edifice. Preliminary results from pre-2006 topography provide three insights. First, the predicted stability of all parts of the upper edifice is approximately the same, suggesting an equal likelihood of slope failure, in agreement with geologic observations that debris avalanches have swept all sectors of the volcano. Second, the least stable (by a small amount) sector is on the east flank where a debris avalanche would flow into deeper ocean water and a resulting tsunami would be directed toward the southwestern part of the Kenai Peninsula. Third, most model scenarios predict stable edifice slopes, and only scenarios assuming extensive weak rocks and moderate to strong ground shaking predict potential large collapses. Because other transient triggering mechanisms, such as shallow magma intrusion, may be needed to instigate slope instability, monitoring ground deformation and seismicity could

Study Area

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Preliminary slope-stability analysis of Augustine Volcano: Chapter 14 in The 2006 eruption of Augustine Volcano, Alaska
Series title Professional Paper
Series number 1769
Chapter 14
DOI 10.3133/pp176914
Year Published 2010
Language English
Publisher U.S. Geological Survey
Contributing office(s) Alaska Volcano Observatory
Description 12 p.
Larger Work Type Report
Larger Work Title The 2006 eruption of Augustine Volcano, Alaska
First page 321
Last page 332
Country United States
State Alaska
Online Only (Y/N) Y
Additional Online Files (Y/N) N