A weekly feature provided by scientists at the Hawaiian Volcano Observatory.
February 13, 2014
Sled dogs slide by vigorous volcanoesWhile most football fans have recovered from Super Bowl XLVIII, the most exciting time of year is just beginning for sled-dog-racing enthusiasts. As this article goes to press, the final finishers of the 1,600-km (1,000-mi) Yukon Quest sled-dog race will have traversed the rugged Alaskan interior and crossed the finish line in Yukon, Canada.
Just around the corner, the Super Bowl of sled dog racing, the Iditarod, is scheduled to begin its run from Anchorage to Nome in unseasonably warm temperatures and marginal snow conditions. This premier event of the sled-dog-racing world commemorates a life-saving dog-sled transport of anti-diphtheria serum to Nome in 1925.
Sled-dog racers are familiar with the myriad challenges that nature can deliver as they mush their way through white-outs, blizzards, and 40 degree Celsius (40 degree Fahrenheit) temperatures. This year, with less than two weeks until race time, the warm temperatures and lack of snow have put the Iditarod route in limbo. Organizers may have to relocate the starting line 560 km (350 mi) north to Fairbanks, where there is better snow for the 1,770-km (1,100-mi) crossing to Nome.
While weather can play a starring role in sled-dog racing, other forces of nature exert their influence, as well. In early 2009, as Iditarod mushers and their dogs were busy training for the event, the specter of volcanic eruption loomed over the race preparations.
In the fall of 2008, seismicity at Redoubt Volcano, located 160 km (100 mi) southwest of Anchorage, had begun to increase. Volcanic unrest escalated over the ensuing months, suggesting that an eruption was likely. Prior eruptions of this frequently active Cook Inlet volcano had caused extensive damage, so Redoubt's rumblings had to be taken seriously.
For instance, the 19891990 Redoubt eruption was the second most costly in the history of the United States. Over a period of 6 months, 23 major explosive events blasted ash plumes as high as 13.7 km (45,000 ft) into the atmosphere. Airborne ash poses a threat to aircraft, as it can diminish visibility, damage flight control systems, and cause jet engines to fail. Heavy ash fall affects communities by collapsing roofs and causing health symptoms in exposed populations.
During the Redoubt eruption, 5 commercial jetliners were damaged by ash, and tragedy was narrowly averted when a KML 747 passenger jet inadvertently flew through an ash plume and lost power to all 4 of its engines. While the pilot managed to eventually restart the plane, the event was a wake-up call that helped set the stage to address aviation safety during volcanic eruptions worldwide.
Airports in Anchorage and to the southeast on the Kenai Peninsula were closed for several days, and drifting ash clouds disrupted air traffic as far away as Texas. The eruption also had an impact on the Alaska oil industry, causing a temporary shut-down of some operations. Schools were closed in downwind communities, and sensitive individuals experienced respiratory problems.
Fast forward to 2009, when the seismic activity of Redoubt was escalating and concern mounted that the March 8th start of the Iditarod would be disrupted by an eruption. Race contenders close to the volcano were daunted by the potential of having to evacuate hundred-dog kennels to a safe, ash-free area, where they could continue to train their canine athletes for the demanding endurance event.
As it turned out, Redoubt began its 2009 sequence of eruptions a week after the mushers were well on their way to Nome. During a three-week period,19 major ash-producing explosions generated ash clouds reaching heights between 5.2 km (17,000 ft) and 18.9 km (62,000 ft) above sea level. During ash falls in Anchorage, the International Airport was closed, and most air travel in Southcentral Alaska was disrupted.
With more than 90 volcanoes that might be expected to erupt again in the future, volcanic activity will surely continue to impact the natural and human environment in Alaska. We wish the 2014 Iditarod competitors a safe and memorable journey through the beautiful Alaskan landscape, in which volcanoes play an important role. More information on Alaskan volcanoes and ash hazards can be found at www.avo.alaska.edu.
Kīlauea Activity UpdateA lava lake within Halemaʻumaʻu produced nighttime glow that was visible via HVO's Webcam during the past week. The lava level rose slightly and was about 40 m (130 ft) below the rim of the Overlook crater.
On Kīlauea's East Rift Zone, the Kahaualeʻa 2 flow continued to be active northeast of Puʻu ʻŌʻō. After the flow front stalled two weeks ago at a distance of 7.8 km (4.8 mi) northeast of Puʻu ʻŌʻō, surface flows have been active behind the stalled flow front, up to 7.2 km (4.5 mi) northeast of Puʻu ʻŌʻō. Webcam images indicate that small forest fires are continuing.
There were no earthquakes reported felt on the Island of Hawaiʻi in the past week.
Visit our Web site (hvo.wr.usgs.gov) for detailed Kīlauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call (808) 967-8862 for a Kīlauea activity summary; email questions to askHVO@usgs.gov.