Redoubt erupted in , , and most recently in The eruption in spewed volcanic ash to a height of 14, m 45, ft and managed to catch KLM Royal Dutch Airlines flight a Boeing aircraft in its plume. The eruption of Redoubt Volcano shares many similarities with eruptions documented most recently at Redoubt in —68 and — In each case, the eruptive phase lasted several months, consisted of multiple ashproducing explosions, produced andesitic lava and tephra, removed significant amounts of ice from the summit crater and Drift glacier, generated lahars that inundated the Drift River valley, and culminated with the extrusion of a lava dome in the summit crater.
Prior to the explosive phase of the eruption, precursory seismicity lasted approximately six months with the fi rst weak tremor recorded on September 23, The first phreatic explosion was recorded on March 15, and the first magmatic explosion occurred seven days later, at on March The onset of magmatic explosions was preceded by a strong, shallow swarm of repetitive earthquakes that began about on March 20, , less than three days before an explosion.
Then another lava dome grew in Redoubt's summit crater. Photography and thermal images showed that the dome, as of April 17, , was about m by m ft by ft in size and at least 50 m ft thick.
The dome growth was accompanied by emissions of volcanic ash and gases. The Alaska Volcano Observatory cautioned that there would likely be additional cycles of dome-building and explosions in the coming days to months, but their nature and timing are uncertain.
They warned that the summit domes could become unstable and produce hot rock avalanches, pyroclastic flows, and ash columns, and melting snow on Redoubt would likely produce more lahars that may threaten downstream areas. In order to better monitor Redoubt's eruptions, scientists at AVO installed several new seismometers, GPS receivers, and a new webcam, and carefully monitored the lava dome, seismic activity, and gas emissions at the volcano.
Volcanic Lightning: Lightning that formed in the ash cloud over Redoubt Volcano during an eruption on March 27, More information. Photo by Bretwood Higman. Her concentration is in volcanology, and she is currently researching lava dome collapses and pyroclastic flows. She also writes the Magma Cum Laude blog , and in what spare time she has left, she enjoys rock climbing and playing various stringed instruments.
Simplified plate tectonics cross-section Simplified plate tectonics cross-section showing how Redoubt is located above a subduction zone formed where the Pacific and North America plates collide. Map: Where is Redoubt? Redoubt: Steam and Ash Eruption Redoubt steam and ash eruption: Aerial view, looking north, of Redoubt Volcano during a continuous, low-level eruption of steam and ash on December 18, Did You Know?
Areas where explosive volcanic eruptions are common, such as the Kamchatka Peninsula in Russia, the islands of Indonesia and the Philippines, and the highlands of Central and South America, are constantly being monitored in order to prevent disastrous interaction between aircraft and volcanic clouds.
They use visual, chemical and thermal satellite data as well as direct visual observations to identify dangerous ash clouds, and issue alerts to aviation control administrations around the world. Redoubt Volcano: One of the Eruptions Redoubt eruption: The most recent eruptive activity at Redoubt volcano began on March 22, Spatter Cones Mount St.
Find Other Topics on Geology. Maps Volcanoes World Maps. Facts About Redoubt. Where Are the Canary Islands? Spatter Cones. The January 8 event occurred with no precursory warnings and the resulting ashfall on the Kenai Peninsula disrupted commerce and transportation.
Open-vent eruptions on January 11 and 16 resulted in minor debris flows down the Drift River. After the January 16 eruption, another period of dome growth ensued through mid-February. This dome was smaller than the earlier dome but larger than succeeding domes Miller, Early on February 15, the dome was destroyed in an explosive eruption that again sent a large debris flow down the Drift River and blanketed the lower Kenai Peninsula with ash.
A pyroclastic flow and surge traveled down the canyon, across the piedmont lobe of Drift Glacier, and swept up the opposite valley wall m topping the ridge.
Flow down the Drift River was largely diverted into a side drainage that carried flood waters close to oil storage tanks at the downstream oil terminal prompting reinforcement of the containment dikes surrounding the tank farm. A new dome began growing immediately following the eruption. On February 21, the new, but considerably smaller, dome was destroyed, marking the beginning of a new trend in eruptive behavior. Characteristically, small domes were emplaced and subsequently destroyed explosively or by gravitational collapse, resulting in debris avalanches down the now ice-free canyon leading down to the Drift River valley, and flooding down the Drift River.
Ten such eruptions followed from February 24 to April 21 at 4 to 8 day intervals.
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