Augustine 1986/3
Start: 00:00:00 March 27, 1986 [1]
Stop: September 10, 1986 [2]
Event Type: Explosive
Max VEI: 4 [3]
- Central eruption [3]
Description: From Swanson and Kienle (1988): "Precursory seismic activity was first detected in July 1985, 8 months prior to the 1986 eruption. A sharp increase in seismicity in March 1986 led to speculation about a possible eruption (Kienle, 1986). A several-order-of-magnitude increase in seismic event counts on the morning of March 26 heralded the eruption that began on the morning of March 27. A short-term forecast of the eruption was made on the afternoon of March 26 (Kienle and others, 1986).
"The initial phase of the eruption involved explosive removal of a portion of the 1976 dome and formed a small (about 100 m in diameter) vent on the southwest flank of the dome (Miller and others, 1987; Yount and Miller, 1987). Numerous pyroclastic flows were observed during the 103 hours of this first eruptive phase, and eruption columns reached heights in excess of 12,000 m (Yount and others, 1987). Pyroclastic flows were directed through the breach in the north side of the crater and spread out on the lower flanks of the volcano. Some of these pyroclastic flows reached the sea to the west and east of Burr Point, and ash cloud surges continued for some distance offshore.
"Prevailing winds on March 27 and 28 were from the southwest and spread ash throughout Cook Inlet. Later on March 28, the winds shifted to the west and finally to the north on March 30 and 31. Ash was thus scattered over populated areas in Cook Inlet only during the early stages of the eruption, but the dust lingered in the air over Cook Inlet, including Anchorage, until March 31.
"Lava was extruded during the second eruptive phase from April 23 to 28. A short blocky lava flow issued from the base of the 1976 dome remnant. Pyroclastic flows descended from the growing dome, but none of them reached the sea.
"* * * A period of accelerated dome growth between August 30 and 31, 1986, resulted in an increase of pyroclastic flow activity. Flows moved down the north flank of the volcano for distances up to 2.2 km from the source (Kienle, 1986). Eruption clouds rose 1000 to 2000 m above the volcano during this episode. None of the pyroclastic flows reached the sea.
"High-silica, two-pyroxene andesite, similar to that produced in previous Mount St. Augustine eruptions was also erupted in 1986 (Swanson and others, 1986; Harris and others, 1987). Groundmass glass in the 1986 andesites is rhyolitic in composition, as in past eruptions, and this is one factor in the explosive character of the eruption. Distribution of eruptive products and volumes of material erupted in 1986 was also similar to other historic eruptions.
"Pyroclastic flow deposits were restricted to the north flank of the volcano, the result of funneling through the breach in the north side of the crater. Lahars composed of reworked air fall deposits form a circular pattern around the upper part of the cone. On the south flank, lahars descended to about 300 m above sea level.
"The new dome occupies the central part of the volcano and a small lava flow extends just a few hundred meters from the dome. A new 50-m-high spine was extruded during the August phase of renewed dome growth. Since then, a large section of the 1986 dome has collapsed and has formed a debris avalanche deposit on the upper northern slope of the volcano.
"Incandescent vents were discovered on August 28, 1987, at the southern base of the spine, with maximum fumarole temperature of 88 degrees C (R. Symonds, personal communication, 1987).
"A new topographic map of Augustine Island was prepared by North Pacific Aerial Surveys for the U.S. Geological Survey from aerial photography taken on September 9, 1986, using geodetic control points surveyed by University of Alaska and U.S. Geological Survey personnel on June 6, 1986 (J. Power, personal communication, 1986). The map shows that the 1986 dome had reached a height of 1252 m by September 9, 1986. Thus the dome gained about 26 m in elevation between 1976 and 1986. The highest point of the volcano is the south peak, which remained unchanged at 1252 m. More changes in dome height could have occurred since then, but the dome has not yet been resurveyed. The total expanded volume of the 1986 pyroclastic flow deposits on Augustine Island is estimated to be close to the 1976 pyroclastic flow volume of about 0.05 cubic km, but could be a little larger."
The April edition of the Scientific Event Alert Network Bulletin (v. 11, n. 04) gives an inflated material estimate of 0.11 cubic km for the March 31 pyroclastic flow, and an estimate volume for the dome (as of May 6) of 0.06 cubic km.
"The initial phase of the eruption involved explosive removal of a portion of the 1976 dome and formed a small (about 100 m in diameter) vent on the southwest flank of the dome (Miller and others, 1987; Yount and Miller, 1987). Numerous pyroclastic flows were observed during the 103 hours of this first eruptive phase, and eruption columns reached heights in excess of 12,000 m (Yount and others, 1987). Pyroclastic flows were directed through the breach in the north side of the crater and spread out on the lower flanks of the volcano. Some of these pyroclastic flows reached the sea to the west and east of Burr Point, and ash cloud surges continued for some distance offshore.
"Prevailing winds on March 27 and 28 were from the southwest and spread ash throughout Cook Inlet. Later on March 28, the winds shifted to the west and finally to the north on March 30 and 31. Ash was thus scattered over populated areas in Cook Inlet only during the early stages of the eruption, but the dust lingered in the air over Cook Inlet, including Anchorage, until March 31.
"Lava was extruded during the second eruptive phase from April 23 to 28. A short blocky lava flow issued from the base of the 1976 dome remnant. Pyroclastic flows descended from the growing dome, but none of them reached the sea.
"* * * A period of accelerated dome growth between August 30 and 31, 1986, resulted in an increase of pyroclastic flow activity. Flows moved down the north flank of the volcano for distances up to 2.2 km from the source (Kienle, 1986). Eruption clouds rose 1000 to 2000 m above the volcano during this episode. None of the pyroclastic flows reached the sea.
"High-silica, two-pyroxene andesite, similar to that produced in previous Mount St. Augustine eruptions was also erupted in 1986 (Swanson and others, 1986; Harris and others, 1987). Groundmass glass in the 1986 andesites is rhyolitic in composition, as in past eruptions, and this is one factor in the explosive character of the eruption. Distribution of eruptive products and volumes of material erupted in 1986 was also similar to other historic eruptions.
"Pyroclastic flow deposits were restricted to the north flank of the volcano, the result of funneling through the breach in the north side of the crater. Lahars composed of reworked air fall deposits form a circular pattern around the upper part of the cone. On the south flank, lahars descended to about 300 m above sea level.
"The new dome occupies the central part of the volcano and a small lava flow extends just a few hundred meters from the dome. A new 50-m-high spine was extruded during the August phase of renewed dome growth. Since then, a large section of the 1986 dome has collapsed and has formed a debris avalanche deposit on the upper northern slope of the volcano.
"Incandescent vents were discovered on August 28, 1987, at the southern base of the spine, with maximum fumarole temperature of 88 degrees C (R. Symonds, personal communication, 1987).
"A new topographic map of Augustine Island was prepared by North Pacific Aerial Surveys for the U.S. Geological Survey from aerial photography taken on September 9, 1986, using geodetic control points surveyed by University of Alaska and U.S. Geological Survey personnel on June 6, 1986 (J. Power, personal communication, 1986). The map shows that the 1986 dome had reached a height of 1252 m by September 9, 1986. Thus the dome gained about 26 m in elevation between 1976 and 1986. The highest point of the volcano is the south peak, which remained unchanged at 1252 m. More changes in dome height could have occurred since then, but the dome has not yet been resurveyed. The total expanded volume of the 1986 pyroclastic flow deposits on Augustine Island is estimated to be close to the 1976 pyroclastic flow volume of about 0.05 cubic km, but could be a little larger."
The April edition of the Scientific Event Alert Network Bulletin (v. 11, n. 04) gives an inflated material estimate of 0.11 cubic km for the March 31 pyroclastic flow, and an estimate volume for the dome (as of May 6) of 0.06 cubic km.
Impact: Air traffic in south-central Alaska was disrupted, especially in the upper Cook Inlet basin from March 27 to 30. Notices to Airmen were issued by the FAA warning of the hazard and restricting flights around the volcano. Most flights were either canceled or diverted. On March 28 the Anchorage International Airport served 16 flights when they normally serve 300. From March 27 to 30 military aircraft at Elmendorf Air Force Base were deployed to other bases. Aircraft schedules were resumed by March 31. Damage to aircraft included abrasion to windshield and turbine parts, and contaminating hydraulic fluid.
On March 27 many businesses in Anchorage were closed and electrical consumption was curtailed. Anchorage air was just below the limits of health emergency with 862mg/m^3 of particulate material on March 28. Ashfall was recorded at Homer and Kenai, with a dusting in the Anchorage area
Radio and television warnings were broadcast by Alaska Division of Emergency Services and the Kenai Peninsula Borough Emergency Management Office advising people of the potential tsunami hazard. [9] [10] [1] [11] [12] [7]
Aircraft Impact: From Kienle and Swanson (1989): "A Sabina airlines DC10 descended through Mount St. Augustine ash during approach to Anchorage International Airport and landed in near-zero visibility and suffered some abrasion to the windowshield and the turbine parts. The Anchorage Airport was never officially closed, but most commercial carriers either canceled or diverted the Anchorage flights."
From Kienle and Swanson (1987): "A couple of incidents involving volcanic dust pitting windshields and contaminating hydraulic fluid were reported by aircraft flying through volcanic dust clouds ***Airlines voluntarily stopped operations in and out of Anchorage during the initial phase of the eruption."
From Yount et. al. (1987): "Airborne ash disrupted air traffic in south-central Alaska, especially in the upper Cook Inlet basin from March 27 to 30. The FAA issued Notices to Airmen warning of the hazard and restricting flights around the volcano. Most commercial and general aviation flights were either canceled or diverted to airports away from the affected area as ash stagnated in the atmosphere over Cook Inlet. On March 28, when Anchorage International Airport would ordinarily have handled 300 flights, 16 flights were served (The Anchorage Times, March 29, 1986). Military aircraft stationed at Elmendorf Air Force Base were deployed to other bases during the period March 27-30. By March 31, as the atmosphere around Anchorage cleared, aircraft schedules were resumed. Despite these precautions, slight damage to aircraft was reported. For example, on March 29, a DC-10 on descent into Anchorage flew through a cloud of disseminated ash, causing minor damage to engine parts and light frosting on its windshield." [9] [10] [1] [11]
Other Impacts: "On 28 and 29 August, Maurice and Katia Krafft and Juergen Kienle visited Augustine Island . . .Leaves and wildflowers were wilted brown from heavy ash accumulation and passage of SO2 clouds." From Whitehorse Star (1986): Kenai airport closed Friday morning [March 28] due to ash buildup. Health alert in Anchorage. From Kienle and Swanson (1989): "In Anchorage, many businesses were closed on March 27, and electrical consumption was curtailed. The air in Anchorage contained 862mg/m^3 of particulate material on March 28, just below the limits of health emergency. Air fall of ash in communities around Cook Inlet was maximum at Homer, where 6 mm of ash was deposited." From Kienle and Swanson (1987): "Concern for airborne volcanic dust in the Anchorage area prompted closing of some businesses and public services." From Smithsonian Institution (1986): An estimated 1.5 cm of ash on Kenai and dusting the Anchorage area From Yount et. al. (1987): "Chugach Electric Company requested the public to curtail unnecessary electrical use on March 27 in anticipation of a possible shortfall in power supply due to shutdown of the turbines. Employers responded by sending workers home early and shutting down computers and other machines sensitive to ash abrasions; a 13% drop in electrical consumption resulted (The Anchorage Times, March 29, 1986)." ***"Alaska Division of Emergency Services and the Kenai Peninsula Borough Emergency Management Office broadcast radio and television warnings advising people of the potential [tsunami] hazard." [7] [12] [9] [10] [1] [11]
Images
References Cited
[1] Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 03, unpaged.[2] Seismicity associated with the 1986 eruption of Augustine Volcano, Alaska, 1988
Power, John, 1988, Seismicity associated with the 1986 eruption of Augustine Volcano, Alaska: University of Alaska Fairbanks unpublished M.S. thesis, 142 p.[3] Volcanoes of the world: an illustrated catalog of Holocene volcanoes and their eruptions, 2003
Siebert, L., and Simkin, T., 2002-, Volcanoes of the world: an illustrated catalog of Holocene volcanoes and their eruptions: Smithsonian Institution, Global Volcanism Program Digital Information Series GVP-3, http://volcano.si.edu/search_volcano.cfm, unpaged internet resource.
[4] Rheological properties, emplacement velocities, and grain size analysis of the 1986 pyroclastic flows at Mt. St. Augustine, Alaska, 1991
Limke, A. J., 1991, Rheological properties, emplacement velocities, and grain size analysis of the 1986 pyroclastic flows at Mt. St. Augustine, Alaska: University of Alaska Fairbanks unpublished M.S. thesis, 155 p.
full-text PDF 2.02 MB [5] Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 04, unpaged.[6] Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 07, unpaged.[7] Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 08, unpaged.[8] Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 05, unpaged.[9] Augustine, 1989
Kienle, J., and Swanson, S. E., 1989, Augustine: in Annual report of the world volcanic eruptions in 1986, Bulletin of Volcanic Eruptions, v. 26, p. 57-58.[10] The 1986 activity of Mt. St. Augustine: volcanic hazards in the Cook Inlet Basin, 1987
Kienle, J., and Swanson, S. E., 1987, The 1986 activity of Mt. St. Augustine: volcanic hazards in the Cook Inlet Basin [abs.]: in Geologic Hazards Symposium, Alaska Geological Society Symposium Agenda and Abstracts, Anchorage, Alaska, May 12-15, 1987, unpaged.[11] The 1986 eruptions of Augustine Volcano, Alaska, hazards and effects, 1987
Yount, E. M., Miller, T. P., and Gamble, B. M., 1987, The 1986 eruptions of Augustine Volcano, Alaska, hazards and effects: in Geologic studies in Alaska by the U.S. Geological Survey during 1986, U.S. Geological Survey Circular C 0998, p. 4-13.[12] Alaskan volcano erupts, 1986
Associated Press, 1986, Alaskan volcano erupts: Whitehorse Star, v. 86, n. 62, p. 1, 4.Complete Eruption References
10 years of volcanic activity in Alaska: 1983-1992: A video (Pyre Peak, Akutan, Bogoslof, Westdahl, Veniaminof, Augustine, Redoubt, and Spurr volcanoes), 1995
Doukas, M. P., McGimsey, R. G., and Dorava, J. M., 1995, 10 years of volcanic activity in Alaska: 1983-1992: A video (Pyre Peak, Akutan, Bogoslof, Westdahl, Veniaminof, Augustine, Redoubt, and Spurr volcanoes): U.S. Geological Survey Open-File Report 95-0061-A, Anchorage, AK, KAKM Video, 1 videocassette.
Hard Copy held by AVO at FBKS - CEC shelf
Augustine, 1989
Kienle, J., and Swanson, S. E., 1989, Augustine: in Annual report of the world volcanic eruptions in 1986, Bulletin of Volcanic Eruptions, v. 26, p. 57-58.
Hard Copy held by AVO at FBKS - CEC file cabinet
Volcanic ash-aircraft incidents in Alaska prior to the Redoubt eruption on 15 December 1989, 1994
Kienle, Juergen, 1994, Volcanic ash-aircraft incidents in Alaska prior to the Redoubt eruption on 15 December 1989: in Casadevall, T. J., (ed.), Volcanic ash and aviation safety: proceedings of the first international symposium on volcanic ash and aviation safety, U.S. Geological Survey Bulletin 2047, p. 119-123.
full-text PDF 182 KB 
Augustine volcano erupts quietly, 1986
Kleist, Trina, 1986, Augustine volcano erupts quietly: Science News, v. 130, n. 10, p. 149.
Hard Copy held by AVO at FBKS - CEC file cabinet
Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 02, unpaged.
Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 03, unpaged.
Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 04, unpaged.
Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 05, unpaged.
Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 07, unpaged.
Augustine, 1986
Smithsonian Institution, 1986, Augustine: Scientific Event Alert Network Bulletin v. 11, n. 08, unpaged.
Volcanoes of the world: an illustrated catalog of Holocene volcanoes and their eruptions, 2003
Siebert, L., and Simkin, T., 2002-, Volcanoes of the world: an illustrated catalog of Holocene volcanoes and their eruptions: Smithsonian Institution, Global Volcanism Program Digital Information Series GVP-3, http://volcano.si.edu/search_volcano.cfm, unpaged internet resource.
Alaskan volcano erupts, 1986
Associated Press, 1986, Alaskan volcano erupts: Whitehorse Star, v. 86, n. 62, p. 1, 4.
Hard Copy held by AVO at FBKS - CEC file cabinet
Sky high, 1988
Unknown, 1988, Sky high: National Geographic World, n. 158, p. 24.
The 1986 activity of Mt. St. Augustine: volcanic hazards in the Cook Inlet Basin, 1987
Kienle, J., and Swanson, S. E., 1987, The 1986 activity of Mt. St. Augustine: volcanic hazards in the Cook Inlet Basin [abs.]: in Geologic Hazards Symposium, Alaska Geological Society Symposium Agenda and Abstracts, Anchorage, Alaska, May 12-15, 1987, unpaged.
Hard Copy held by AVO at FBKS - CEC file cabinet
Hard Copy held by AVO at FBKS - CEC shelf
Anatomy of 1986 Augustine volcano eruptions as recorded by multispectral image processing of digital AVHRR weather satellite data, 1991
Holasek, R. E., and Rose, W. I., 1991, Anatomy of 1986 Augustine volcano eruptions as recorded by multispectral image processing of digital AVHRR weather satellite data: Bulletin of Volcanology, v. 53, n. 6, p. 420-435.
Hard Copy held by AVO at FBKS - CEC file cabinet
Rheological properties, emplacement velocities, and grain size analysis of the 1986 pyroclastic flows at Mt. St. Augustine, Alaska, 1991
Limke, A. J., 1991, Rheological properties, emplacement velocities, and grain size analysis of the 1986 pyroclastic flows at Mt. St. Augustine, Alaska: University of Alaska Fairbanks unpublished M.S. thesis, 155 p.
full-text PDF 2.02 MB 
Seismicity associated with the 1986 eruption of Augustine Volcano, Alaska, 1988
Power, John, 1988, Seismicity associated with the 1986 eruption of Augustine Volcano, Alaska: University of Alaska Fairbanks unpublished M.S. thesis, 142 p.
The 1986 eruption of Augustine Volcano, Alaska: magma storage and ascent, 2001
Roman, D. C., 2001, The 1986 eruption of Augustine Volcano, Alaska: magma storage and ascent: University of Oregon unpublished M.S. thesis, 129 p.
Debris avalanches and lateral blasts at Mount St. Augustine volcano, Alaska, 1989
Siebert, L., Glicken, H., and Kienle, J., 1989, Debris avalanches and lateral blasts at Mount St. Augustine volcano, Alaska: National Geographic Research, v. 5, n. 2, p. 232-249.
The 1883 and late-prehistoric eruptions of Augustine volcano, Alaska, 1995
Siebert, Lee, Beget, J. E., and Glicken, Harry, 1995, The 1883 and late-prehistoric eruptions of Augustine volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 66, n. 1, p. 367-395.
Debris avalanches, lateral blasts, and tsunamis: volcanic hazards at Mount St. Augustine, Alaska, 1988
Siebert, Lee, Glicken, Harry, and Kienle, Juergen, 1988, Debris avalanches, lateral blasts, and tsunamis: volcanic hazards at Mount St. Augustine, Alaska: in Kagoshima international conference on Volcanoes, proceedings, Kagoshima, Japan, July 19-23, 1988, p. 452-455.
Hard Copy held by AVO at FBKS - CEC file cabinet
The 1986 eruptions of Augustine Volcano, Alaska, hazards and effects, 1987
Yount, E. M., Miller, T. P., and Gamble, B. M., 1987, The 1986 eruptions of Augustine Volcano, Alaska, hazards and effects: in Geologic studies in Alaska by the U.S. Geological Survey during 1986, U.S. Geological Survey Circular C 0998, p. 4-13.
Hard Copy held by AVO at FBKS - CEC file cabinet
Hard Copy held by AVO at FBKS - CEC shelf
The 1986 eruption of Mount St. Augustine: field test of a hazard evaluation, 1988
Swanson, S. E., and Kienle, J., 1988, The 1986 eruption of Mount St. Augustine: field test of a hazard evaluation: Journal of Geophysical Research, v. 93, n. B5, p. 4500-4520.
Hard Copy held by AVO at FBKS - CEC file cabinet
Weather may ease Anchorage impact, 1986
Lipka, Mitch, 1986, Weather may ease Anchorage impact: Anchorage Times, March 29 1986, p. A1, A8.
Hard Copy held by AVO at FBKS - CEC file cabinet
10 years of volcanic activity in Alaska: 1983 to 1992: a video, 1995
Doukas, M. P., McGimsey, R. G., and Dorava, J. M., 1995, 10 years of volcanic activity in Alaska: 1983 to 1992: a video: U.S. Geological Survey Open-File Report 95-61-B, 12 p.
Hard Copy held by AVO at FBKS - CEC file cabinet
Hard Copy held by AVO at FBKS - CEC shelf
Volcanic processes and geology of Augustine Volcano, Alaska, 2009
Waitt, R.B., and Beget, J.E., 2009, Volcanic processes and geology of Augustine Volcano, Alaska: U.S. Geological Survey Professional Paper 1762, 78 p., 2 plates, scale 1:25,000, available at http://pubs.usgs.gov/pp/1762/ .