Bouncing Back After an Eruption of Makushin Volcano

This paper investigates the possible outcomes of an eruption of Makushin Volcano, specifically depicted in this paper, the impact on the community of Unalaska. It has been determined that the ash from a volcanic eruption would be the most threatening aspect of an eruption of Makushin Volcano.

Abstract

This paper investigates the possible outcomes of an eruption of Makushin Volcano, specifically depicted in this paper, the impact on the community of Unalaska. It has been determined that the ash from a volcanic eruption would be the most threatening aspect of an eruption of Makushin Volcano. The potential outcomes of falling ash would affect everyday life of the community of Unalaska and pose numerous safety hazards. The health and well being of the citizens of Unalaska could very well be at stake if there was a volcanic eruption. With the current city plans, the water and energy sources of Unalaska would be held in abeyance during a volcanic eruption, because falling ash would contaminate and stall the use of these utilities.

To mitigate the outcomes of such volcanic activity, this paper is composed of possible planning measures the City of Unalaska could make. Planning and preparation related to energy, water, infrastructure, and the possibility of an evacuation are crucial in the resilience of the community of Unalaska. Within this plan there is a focus on the importance of the City of Unalaska finding a new water source or better filtration system for the impending water contamination issue, and the investing in another energy source that would not be affected by falling ash. In sum, the creating or adopting an action plan would greatly benefit the City of Unalaska.

Geology

Volcanoes

Volcanoes form when molten rock, debris, and gases from the planet’s interior are expelled onto the Earth’s crust (Science Learning [SL], 2010). Often, these volcanoes form along the boundaries of the tectonic plates that lie in the lithosphere. These tectonic plates are rigid and float atop the asthenosphere, a much hotter and more viscous layer of the Earth’s interior. When two tectonic plates collide, the plate that is denser will sink, or subduct, into the asthenosphere (SL, 2010). The temperature of the asthenosphere melts the subducted tectonic plate and turns it into molten rock, or magma. This magma then rises to the Earth’s crust and causes an eruption. Repeated eruptions create an accumulation of hardened magma, which is how volcanoes are initially formed (Figure 1).

Subduction zones, such as the Ring of Fire, are notorious for their high rates of volcanism and seismic activity. The Ring of Fire is an area surrounding the Pacific Ocean, where the Pacific Tectonic Plate subducts into multiple other surrounding tectonic plates. This 40,000 kilometer, nearly continuous series of oceanic trenches, volcanic island chains, and volcanic mountain ranges line the coasts of the surrounding continents, including South America, North America, Asia, and Australia (SL, 2010). Similar to the Ring of Fire, island arcs are also formed by subduction along plate boundaries. These chains of oceanic islands are associated with intense volcanic and seismic activity, inherently, because most island arcs are located along the Ring of Fire (SL, 2010). One of the numerous island arcs created by the Pacific Tectonic Plate is the Aleutian-Arc, located east of Kamchatka between the Bering Sea and the Pacific Ocean forming the Aleutian Chain of Alaska (Coats, 1950).

Makushin Volcano

The Aleutian Arc consists of 76 major volcanoes, 36 of which are geologically active, meaning they have erupted in the past 10,000 years (Coats, 1950). Makushin Volcano, located on Unalaska Island, has been labeled as being ‘potentially the most threatening volcano in the Aleutian Arc,’ due to both its proximity to the City of Unalaska, along with its extensive eruptive history (Lerner, 2010). Makushin Volcano is the highest point on Unalaska Island, standing at 1,800 meters, and is 16 kilometers wide in basal diameter. The volcano itself occupies the majority of the northwest extension of the island. Makushin Volcano is located a mere 28 kilometers from the population center of the City of Unalaska (Beget, Nye & Bean, 2000).

History of Makushin

Due to records kept from Russian explorers and traders, it is known that Makushin has had over 17 explosive eruptions since the 1700’s (Coats, 1950). All of these written records document the eruptions as being relatively small, sending ash 3 to 10 kilometers above the volcano’s summit, and depositing ash mainly on the flanks of the volcano. Makushin has most recently erupted in 1995, creating an ash cloud that rose to around 2.5 kilometers above the peak of the volcano (Coats, 1950) (Table 1).

Prehistoric investigation into the past of Makushin reveals volcanic activity of a greater magnitude. Geological studies indicate a much more destructive series of eruptions occurred between 8,000 and 8,800 years ago known as the Driftwood-Pumice deposits (Lerner, 2010). Combined, these eruptions created an ash layer reaching a depth of 1.5 meters, and around 1 meter where the City of Unalaska is located (Lerner, 2010). Along with numerous pyroclastic flows that traveled down Makushin Valley and into Broad Bay. This series of volcanic activity produced a 4 kilometer diameter crater at the summit of Makushin.

Sedimentary records cannot be taken back much further, due to removal by glacial erosion from the last ice age, 10,000 years ago (Beget, Nye, & Bean, 2000). However, Makushin has been volcanically active for at least a million years, as shown by the radiometric dating of a sample of lava found on an eroded cliff at the base of the volcano (Beget, Nye, & Bean, 2000). The potential for an eruption similar to those in the past are unpredictable and a foreboding thought for the future of Unalaska.

Potential Hazards15

The City of Unalaska has a population of approximately 4,000 people, making it the 12th largest city in the State of Alaska (Dutch Harbor, 2015). Its economy is primarily based on commercial Pollock and crab fishing, as well as seafood processing (Dutch Harbor, 2015). The seafood processing companies on the island provide local employment, but non-residents are flown in during the peak seasons, bringing in over 6,000 transient residents during the peak production seasons. All homes and processing plants are served by the city’s piped water system. Almost every home uses the city’s electrical system, but the processors provide their own electricity (UniSea, 2009). Daily scheduled flights are one of the two ways to get to the island, the second being a ferry that operates bi-monthly during the summer months. The bustling town of Unalaska could be detrimentally affected by volcanic activity caused by Makushin Volcano. The City of Unalaska is currently not prepared for such an eruption, with limited city-specific plans detailing how to cope with such an event.

An eruption of Makushin Volcano would affect the community of Unalaska in a multitude of ways. The first and most important way that Unalaska would be affected by the eruption of the Makushin Volcano is the falling ash and ash clouds. In other communities, where cities are of much closer in proximity to the volcano, there is the risk of pyroclastic bombs, lahars, lava flows, and other hazards. The material that the ash clouds are composed of range in size from microscopic to several meters in diameter, and is collectively called tephra. During an eruption, the finer material can rise more than 20 kilometers from the summit, and then be carried by prevailing winds. Tephra can travel through the atmosphere for extended periods of time and across great distances. Depending on the size of the initial eruption, ash clouds have been known to travel hundreds to thousands of kilometers and for periods of days or months (Beget, Nye, & Bean, 2000). During this time and within the affected area, turbine engine aircrafts are not able to operate. The volcanic material within the ash cloud, like volcanic glass, is extremely harmful to an aircraft’s safety.

Redoubt Volcano, an active stratovolcano in the Aleutian Range, erupted several times in 1989-1990. These eruptions sent ash at least 12 kilometers into the atmosphere. On December 15, 1989, a Boeing 747 jet flying 240 kilometers from Anchorage flew into an ash cloud and lost power in all four engines. The plane had 231 passengers onboard, fell more than 3,000 meters before the engines were restarted by the crew (Casadevall, 1994). An ash cloud from Makushin Volcano could potentially cause an equally dangerous situation.

Volcanic ash would also pose a threat on land. The accumulation of falling ash on the roofs of buildings may cause less sturdy roofs to collapse. The weight of dry ash can range from 400 to 700 kg/m3 (USGS, n.d.). Since the chance of rain in Unalaska is very high, an average of 223 days of precipitation per year, this increases the possibility of falling ash destroying roofs (USGS, n.d.). Ash increases in weight by 50-100 percent or more if the ash becomes saturated by rain, and could even reach more than 2,000 kg/m3 (USGS, n.d.).

A prime example of ash damaging buildings is the eruption of Mount Pinatubo in the Philippines in 1991 (USGS, n.d.). The volcanic ash that settled on roofs of buildings accumulated and many roofs could not withstand the weight, and were damaged by 5-10 centimeters of wet ash. Especially buildings with long-span roofs, like warehouses, were susceptible to collapsing under the excessive weight of dry and wet ash (USGS, n.d.). A similar situation could occur in Unalaska, and the accumulation of wet ash would destroy homes and businesses. In such a situation, the canneries and housing facilities would probably see the most damage because, like the warehouses in the Philippines, their elongated roofs would make them more susceptible to damage (USGS, n.d.).

Most importantly the health effects of ash should be duly noted. After an ash fall, there are potential respiratory symptoms from the inhalation of volcanic ash. The abrasive property of ash particles will typically also cause eye and skin discomfort or irritation (USGS, 2010).

Common respiratory complications include nasal discharge (runny nose), throat irritations followed by dry coughing, airway irritation, and uncomfortable breathing. Those with preexisting respiratory problems are especially susceptible to such complications. Short exposure to volcanic ash usually does not create serious health problems, but one should still be careful to limit their exposure. An example of a community affected by ash fall is the 1995-96 eruption of Mount Ruapehu in New Zealand. After the eruption an increase in bronchitis cases was noted, even though the ash fall was light (USGS, 2010). Other than respiratory symptoms, after ash fall people will typically experience eye irritations. People may feel that there are “foreign particles” in their eyes, which can lead to great discomfort and pain. There are not many complications related to short term exposure to ash, long term can have adverse effects on a person’s health (USGS, 2010).

Preliminary Preparation

Preparation is vital for Unalaska to bounce back from an eruption of Makushin Volcano. Without a plan in place, any efforts to mitigate the situation would be inefficient and potentially hazardous. Proper steps need to be in place to insure that in the case of a volcanic eruption, the community of Unalaska would be prepared.

Current Plans in Place

The State of Alaska has the “Alaska Interagency Operating Plan for Volcanic Ash Episodes” that outlines what agencies are responsible for certain duties, should a volcano in Alaska erupt (Office of the Federal Coordinator for Meteorology [OFCM], 2014). The plan is revised every two years, and its intent is to provide an “overview of an integrated, multi-agency response to the threat of volcanic ash in Alaska”. The Alaska Volcano Observatory (AVO) is a joint program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys. The AVO monitors seismic activity in Alaska and studies volcanic activity. In this situation, the AVO would notify the Division of Homeland Security and Emergency Management. This information is then passed down to all relevant agencies, such as the Federal Aviation Administration, the United States Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA). Following notification, those agencies use available tools to alert the public and organizations that might be affected from volcanic activity. Meaning each agency uses what communication portals they have to distribute alerts and safety information. For example, the National Weather Service uses NOAA Weather Wire, marine High Frequency and Very High Frequency radio, NOAA Weather Radio, the statewide Alaska television weathercast, and the Emergency Alert System to get their alerts out to the public. By using a diverse methods to disperse information, this plan quickly and efficiently reaches as many people as possible (OFCM, 2014).

Proposed Implementations

An official emergency response plan for volcanic activity has not been written for the community of Unalaska. Currently the only information the community possesses about proper conduct during a volcanic eruption is represented by the boxes of emergency situations pamphlets at the local Department of Public Safety office. The community needs to made aware of the potential danger of a volcanic eruption and a comprehensive emergency response plan should to be written. Like any emergency response plan, it should be written by experts, but nonetheless the plan that follows proposes elements that should be included in such a plan.

Action before an Eruption

The Unalaska Department of Public Safety currently has 5,000 number of dust masks to distribute out in case of an eruption, and 50 number radios to give to local businesses so that they can stay informed in recovery plans.

A stockpile of emergency preparedness items are essential for before an ash fall. Dust masks and eye protection are necessary, because ash can damage a person’s respiratory system and eyes. People should also have 72 hours’ worth of water and nonperishable food, because food and water may not be available during an emergency situation. Cleaning supplies, such as a broom, vacuum cleaner, and shovels, are needed to remove ash from roofs and the inside of a home. General preparations include buildings equipped with emergency supply kits. The supply kit should include “non-perishable foods, water, a battery-powered or a hand cranked radio, extra flashlights and batteries” and also, “a pair of goggles and a disposable breathing mask” for each person (Volcanoes, 2015).

Actions during an Eruption

During an ash fall, it advised that all people to stay indoors with windows closed. Due to the grave outcomes ensuing the inhaling of excess volcanic material, those who suffer from respiratory problems should be extra wary that they are not spending excessive time outside and, if necessary, to go outside, then a protective dust mask should be worn. Elderly and children should also limit their time outside while ash is falling and even for the proceeding days. Ash in any form, whether it is falling or on the ground, can cause lung and/or throat irritation, being that ash has landed can be swept up by winds or stirred up in other ways (USGS, 2009).

Operating motor vehicles is also not advised during the time of an ash fall event. Heavy ash fall can make the visibility poor and, in extreme cases, complete darkness may ensue after a volcanic eruption. This ash-water mixture creates a mud-like texture, which can make cars lose traction and consequently cause a vehicular accident. Driving should only be done if absolutely necessary, and if one should find themselves in this situation, they should take heed to the dangerous conditions. In the community of Unalaska, the maximum speed limit is 30 miles per hour, and during an ash fall, drivers should reduce their speed to at least 20 to 10 miles per hour. In addition, motorist should wait until the roads have been swept of ash before driving on the roads again. This will help to facilitate the cleanup of ash and limit the stirring up of fallen ash (USGS, 2009).

Resiliency after an Eruption

An eruption of Makushin Volcano could catastrophically affect the community of Unalaska. This is why preparation and proper planning are vital in a speedy recovery. The four primary things that would need to be addressed in a recuperation effort are the City of Unalaska’s possible evacuation plan, water source, energy source, and infrastructure.

Possible Evacuation

An ash fall could cut off Unalaska’s air transportation because of ash clouds and a slippery runway. The issue of a slippery runway can be solved if you properly clean the runway, but the problem of an ash cloud is much more complex.

If an ash cloud is blown in flight paths to Unalaska, planes may not fly which could interfere with emergency medical evacuations and could strain the limited resources at the local clinic. In addition, emergency supplies that are unavailable in Unalaska would have limited means to arrive in Unalaska.

Energy

The City of Unalaska’s primary source of power is a 16.6 megawatt powerhouse. (Fitch, n.d.) In the event of a severe ash fall, the city generator could fail because it requires a constant stream of clean air to cool moving parts. The city’s power source could fail because the generator that the City of Unalaska uses is powered by burning diesel fuel and normally, diesel generators run when diesel fuel is burned to heat up liquid water. The liquid water then turns into compressed steam, which rotates a turbine. The rotational mechanical energy is then turned into electrical energy using a generator (Rozenblat, 2014). However, when ash accumulates on and inside of the turbine, the turbine that makes the generator run will stop functioning efficiently and eventually slow down. Although proper maintenance will be able to get the generator back up and running, it will take time to restore the generator to proper working condition (Loehlein, 2007). Theoretically, this would leave the City of Unalaska without power for an unforeseeable amount of time after a volcanic eruption.

If the city had a more diverse source of energy, resiliency would be easier to achieve. In addition to the maintenance of current power sources, the community of Unalaska could also look into energy that would not be affected during an ash fall. This would include wind power, geothermal energy, and fuel cells.

Water

The City of Unalaska’s primary source of water is from a reservoir. In the event of an ash fall, that source of water could be contaminated with ash which would affect water quality. Harmful water-soluble substances called leachates, which are mostly acids and salts, are usually found in ash. Turbidity, the quality of suspended particles in water, may become a concern. Suspended particles in the water protect micro-organisms and stimulate bacterial growth (USGS, n.d.). Additionally, the chemicals in ash are hazardous if ingested. This would include substances like fluoride, which can be hazardous if excess amounts are ingested. Long-term exposure to fluoride can increase the risk of developing both dental and skeletal fluorosis (Wilson et al., 2011).

Ash leachates are typically acidic, “due to the presence in volcanic plumes of strong mineral acids … and consequently may acidify receiving waters” (Wilson et al., 2011). However, acidification is not a significant worry, because “the majority of surface waters have sufficient alkalinity to buffer against significant pH change” (Wilson et al., 2011).

Ensuing after an eruption, the water reservoirs should be closed before the turbidity and acidity levels become excessive. Turbidity can be managed using filters, but constant cleaning of the filter may become a problem. To insure the safety of the drinking water, a more efficient method of filtration must be developed and implemented in the case of an emergency\.. Alternatively, a new water source could be found, it would have to be one that would not be contaminated by falling ash. A water source that is not exposed to the open air would be most effective in keeping the ash out. In sum, the City of Unalaska would need to invest in finding a new water source and/or filtration method.

Infrastructure

Unfortunately, there isn’t any way to rebuild the roads to make them less susceptible to ash falls, but proper maintenance can help to mitigate the issue. In this situation, proper training of road maintenance crews is imperative for safety and efficiency of ash clean up. Ash cannot be simply swept off the roads, and in some situation can even exacerbate conditions. Road sweepers and passing cars can cause settled ash to get stirred up or billow and create an ash cloud that can last for weeks or months. Ash should not be swept to the side of the road for this very reason. Instead, ash should be lightly moistened to facilitate the process of cleaning up, and motorized graders to scrape and blades to move ash to the middle of the roads. This volcanic material should then be loaded into trucks and hauled to appropriate ash disposal zones. Disposal zones should not be in the proximity of homes or businesses that could be affected by ash. This designated area should be where the ash would later not have to be moved and be somewhat undisturbed by the population (USGS, 2010).

The community should be made aware of these disposal zones, and should be encouraged to make an effort to help clean up ash as well. An example of this would be to organize community cleaning activities. During this time, participants would make a concentrated effort to clean up ash for in neighborhood. Most importantly ash should be removed from the roofs of homes and other buildings too. This is another instance where the community would have to informed on proper ash removal. When removing ash from roofs, wetting of the ash would cause more damage, because the most roofs would not be able to handle the additional weight of wet ash. Like in any other situation, the more informed the community is, the more efficient a clean up and resilience effort would be.

Conclusion

The city of Unalaska, in its current state, is largely unprepared for an eruption of Makushin Volcano. However, a cohesive action plan will help the community to bounce back more quickly in the event of an eruption. If the city were to implement the use of an energy source that would not be affected by falling ash, this would significantly help in the response and maintenance after an eruption. In addition, a secondary source of water would greatly benefit the community. If ash were to pollute the current water source, the community of Unalaska would be without clean water for an unforeseeable amount of time. Being able to filter this tainted water, or find a new source of water that would not be as susceptible to pollution would greatly benefit the City of Unalaska.

Taking into consideration both the proximity of Makushin Volcano to the City of Unalaska and its eruptive history, the possibility of an eruption should not be taken lightly. Creating or adopting an action plan is the first step in this process.

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Bouncing Back After an Eruption of Makushin Volcano

This paper investigates the possible outcomes of an eruption of Makushin Volcano, specifically depicted in this paper, the impact on the community of Unalaska. It has been determined that the ash from a volcanic eruption would be the most threatening aspect of an eruption of Makushin Volcano.

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