Redoubt 2009/3

Start: March 15, 2009 ^[1]

Stop: July 2009 ± 1 Months ^[1]

Event Characteristics:

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Impact: The 2009 eruption of Redoubt caused aviation impacts to Alaska and the Pacific Northwest, ranging from flight cancellations, airport closure, and visual flight rules flying, impact to local commerce in Anchorage and the Kenai Peninsula, and impacts to the Drift River Oil Terminal operations in Cook Inlet. ^[4]
Aircraft Impact: From Schaefer, J.R., ed., 2012: "On January 26, 2009, well before the first explosive release of ash into the atmosphere, FAA imposed a flight restriction below the 60,000-ft flight level within a 10-nautical-mile radius around Redoubt Volcano. During March and April 2009, the NWS Alaska Aviation Weather Unit (AAWU) issued 39 severe weather advisories called SIGMETS (Significant Meteorological Information) to inform the aviation community of volcanic-ash hazards (U.S. Department of Commerce, 2010). Drifting ash clouds as well as the threat of ash fall disrupted aviation-based operations in Alaska. Ash in the atmosphere combined with ash fall in Anchorage caused the closure of the Ted Stevens International Airport for approximately 20 hours March 28-29 (Jim Iagulli, Ted Stevens International Airport Operations Manager, written commun.). During the course of the 2009 eruption, major air carriers canceled at least 295 flights, affecting more than 20,000 passengers (Murray and others, 2009). Numerous local passenger carriers canceled flights within Alaska and for much of the eruption, flying on the Kenai Peninsula was by visual flight rules (VFR) only. Ash in the atmosphere resulted in approximately 60 reroutes, 20 diversions, 10 turn-backs, and many cancellations in night operations, resulting in an ash avoidance cost to air carriers of about $400,000 (International Airways Volcano Watch Operations Group, 2010). In March 2009, Alaska Airlines had an on-time percentage of 70.2 percent, down from 78.0 percent in March 2008, which they attributed in part to disruptions caused by Redoubt (Alaska Airlines press release, April 3, 2009; http://splash.alaskasworld.com/Newsroom/
ASNews/Asstories/AS_20090403_045447.asp). Starting March 22, air cargo carriers began routing through Seattle and Oakland rather than Anchorage, and some implemented temporary layoffs without pay as there was no freight to move in Anchorage. (Anchorage Daily News, March 23). An aircraft maintenance company temporarily furloughed about 50 of its 93 employees during the eruption because there were no planes to de-ice, but then changed business strategy to de-ashing to retain employees (Stapleton, 2009). At the time of this writing, the total economic impact of the Ted Stevens International Airport closure has not been assessed. Military aviation operations were also impacted. In
preparation for possible ash fall or flight restrictions from ash in the atmosphere, Elmendorf Air Force Base in Anchorage moved fiveC-17 aircraft and ~130 airmen to McChord Air Force Base in Washington on February 1. On February 2, they moved three additional C-130J aircraft and ~70 personnel to
McChord. By March 23, Kulis Air National Guard Base had sent five C-130 Hercules and two HC-130 aircraft to Eielson Air Force Base in Fairbanks. ^[4]
Other Impacts: From Schaefer, J.R., ed., 2012: "Heavy tephra fall (as thick as 5 cm) occurred only in locations very near the volcano (within 15 km) and posed no hazards because no infrastructure or people were present. Minor ash deposits (0.8 to 2.0 mm) occurred in communities along the Kenai Peninsula (80-100 km east-southeast), the city of Anchorage (170 km northeast) and Silver Salmon Creek Lodge (48 km south). Trace ash (< 0.8 mm) was reported as far as Fairbanks, 550 km north-northeast of the volcano. Because the eruption occurred during winter months, most ash accumulated on snow surfaces and the darkcolored ash particles absorbed solar radiation and accelerated snow melting, which effectively wetted and 'locked in' the ash deposits, thus preventing significant reworking of the ash. Snowfalls that buried ash fall deposits also buried the hazard, delaying the time when dry ash could be resuspended by wind. Relatively short-duration explosions (<1 to 30 minutes) meant that ash fall on urban and rural communities was also short-lived, lasting no more than 1.5 hours (April 4), but more commonly, lasting 10 to 30 minutes. Early morning or late night ash fall events (March 23, April 4) caused fewer impacts to communities because of lack of exposure. Impacts to communities were relatively minor and more of a distraction and nuisance than a hazard, although economic losses from disruptions to airline travel were significant (see [aviation] section).
Preparedness activities by communities and individuals significantly reduced ground-based impacts (for example,
remaining indoors during ash fall, covering electronics and engine parts, suspending activities during ash fall, wearing dust masks during cleanup, etc.). Local stores stocked up on emergency supplies such as dust masks, air filters, bottled water, and goggles yet sold out periodically (D'Oro, Anchorage Daily News, March 29, 2009). Nonetheless, impacts to local commerce were felt; some were positive and some negative. Significant shipping delays caused by airline flight cancellations resulted in a number of stock shortages at local stores including food supply and floral deliveries (Komarnitsky, Anchorage Daily News, March 31, 2009).
Businesses trading in preparedness and cleanup supplies or services experienced retail booms (D'Oro, Anchorage Daily
News, March 29, 2009). Stranded travelers caused shortterm booms in businesses including rental cars, hotels, and restaurants (Mowry, Fairbanks Daily News-Miner, March 31, 2009). Closures of area clinics during ash fall in Homer on March 26 caused a spike in emergency room visits unrelated to ash fall (Klouda, Homer Tribune, April 1, 2009). Worried pet owners kept veterinary clinic phone lines busy (VCA Animal Hospitals, personal communs.). Ash leachate analyses showed that chemicals adsorbed onto the surface of ash particles that can be leached into water supplies (such as fluoride, chloride, sulfate, and nitrate) were not a significant concern to human or environmental health. Air-quality samplers of ?ne particulate matter (PM) operated by the Municipality of Anchorage (MOA) and the Department of Environmental Conservation (DEC) as well as the U.S. Fish and Wildlife Service (USFWS) detected elevated levels of PM10 and PM2.5 (less than or equal to 10 and less than or equal to 2.5 microns,
respectively) in Anchorage and Soldotna during the eruption. Nevertheless, ? Ne particulate levels never exceeded Environment Protection Agency (EPA) 24-hour average air quality standards. Particles 10 microns (that is, PM10) in diameter and smaller can be inhaled into the respiratory tract, where they can cause harm.
In summary, the most signi? Cant ash fall events in terms of ground-based impacts occurred on March 26 and 28 and April 4, mainly because these events deposited ash in the most populated regions of Alaska. On the afternoon of March 28, ash fall in Anchorage closed Ted Stevens International Airport from 17:00 until around 13:00 the next afternoon (March 29). Although the April 4 ash fall event affected a relatively narrow swath of the lower Kenai Peninsula from Anchor Point to Seldovia, up to 2 mm of ash (the thickest reported ash fall on a populated area) was deposited on snowfree surfaces causing longer-term impacts due to reworking of the ash by wind, cleanup, and normal activities." ^[4]

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