By: Nikki Allen 2010 Teacher on the TrailTM Finalist
With Mt. Redoubt having elevated activity over the last few months, many wonder how the race would be affected if the volcano were to erupt before or during the race. Redoubt is a stratovolcano located on Cook Inlet approximately 105 miles southwest of Anchorage, within Lake Clark National Park. It has an elevation of 10,197 feet and its most recent eruptions have occurred in 1902, 1966-68, and 1989-90. When most people think of a volcano eruption they immediately picture hot red lava spewing from the top of the volcano. Alaska’s volcanoes are quite different, however. When an eruption occurs in Alaska it usually spews ash and not lava, which poses a different hazard to the surroundings. The current threat level of Redoubt is at orange which means that the Alaska Volcano Observatory is on 24-hour watch to constantly monitor activity. The AVO’s monitoring system consists of continuously recording seismometers installed at the volcano where seismic data is then relayed to AVO facilities in Fairbanks and Anchorage. Satellites are also used to provide information that complements seismic monitoring. AVO concentrates heavily on the four Cook Inlet volcanoes because of their close proximity to Alaska population centers.
According to the AVO website, “The Alaska Volcano Observatory (AVO) is a joint program of the United States Geological Survey (USGA), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the state of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO was formed in 1988, and uses federal, state, and university resources to monitor and study Alaska’s hazardous volcanoes, to predict and record eruptive activity and to mitigate volcanic hazards to life and property. AVO has three primary objectives which are:
*To conduct monitoring and other scientific investigation in order to assess the nature, timing, and likelihood of volcanic activity;
*To assess volcanic hazards associated with anticipated activity, including kinds of events, their effects, and areas at risk; and
*To provide timely and accurate information on volcanic hazards and warnings of impending dangerous activity to local, state, and federal officials and to the public.”
In an interview with Taryn Lopez with the Alaska Volcano Observatory, I addressed the issue of the possible hazards to the Iditarod if Redoubt were to erupt. She immediately mentioned that the main hazard would be ash fall from the volcano. Where the ash went would depend on the winds. During the 1989 eruption, the ash did make it to Anchorage. Although it would always be possible for the ash to head north, Taryn informed me that the consistent winds for Redoubt typically head east. If ash fall did make it to Anchorage, one of the major problems would be with air traffic. Because volcanic ash can shut down a plane’s engines, the Iditarod air force may have trouble getting into and out of the airstrip in Anchorage. This, of course, would cause problems with the flow of people, supplies, and dogs during the race. The second concern with ash fall would be the possible health effects. If proper precautions were not taken the volcanic ash could cause eye, nose, and throat problems for the mushers and dogs. The third and final concern of ash fall would be the possible abrasion to sled runners. Because volcanic ash can scratch glass, if sleds were to run over this ash there would be a good chance that their runner plastic would be damaged.
Although Redoubt could erupt at any time, the activity has been fairly quiet in the last week; they have not been experiencing the highest seismic activity. The small discreet earthquakes in the last week are comparable to what was seen in early January. The best policy in the event of an eruption is to know what precautions to take to avoid any harm by volcanic ash. You can find this information by visiting http://volcanoes.usgs.gov/ash/.
For more information on volcanoes please visit the Alaska Volcano Observatory at http://www.avo.alaska.edu or the USGS at http://volcanoes.usgs.gov/.
Lesson Ideas for Volcanoes
1. Map the locations of volcanoes in the United States.
2. Compare the usual natural disasters in Alaska with the usual natural disasters of your state. What are the similarities and differences in the types of things that you need to do to prepare for or react to the disaster.
3. Study the theory of plate tectonics to assess the early location of landmasses by looking at the location of volcanoes worldwide.
4. Study the role that plate movement and shifting has on the activity of a volcano.
5. Explore the interiors of volcanoes and mechanisms of eruption.
6. Investigate the hazards associated with eruptions of snow and ice covered volcanoes.
7. Use geologic mapping to determine eruptive histories of active volcanoes.
