Volcanic Hazards in Alaska
For a week in November, the world's wandering attention was attracted by the eruption of the Columbian volcano Nevada del Ruiz. It reminded us again that we live on a restless planet. We quickly forget, though. How many people think about Mt. St. Helen's these days? Closer to home, I wonder how many Alaskans are aware that our own state hosts most of the volcanoes in North America.
For starters, every single Aleutian Island is, or was, an active volcano. That's a lot, right there. In the western part of the state, the Seward Peninsula is dotted with extinct volcanoes, as is southwest Alaska, St. Lawrence Island and Nunivak Island. Southeast Alaska has Mt. Edgecumbe near Sitka. The Interior has the group of volcanoes centered on Mt. Wrangell. The Alaska Peninsula is crammed with volcanoes, many of them active, and they extend all the way inland to Mt. Spurr, just 80 miles west of Anchorage.
It isn't until one of these monsters erupts that we pay particular heed to them. After all, goes the prevailing sentiment, what can you do about them? Well, if the Colombian government had paid more attention to the geophysicists who told them that Nevada del Ruiz might erupt, the eruption might not have had such tragic results.
The first Alaskan volcano that comes to mind is Katmai. The 1912 eruption made a great National Monument, and nobody (that we know of) was killed. But there are other potentially hazardous volcanoes situated close to population centers in Alaska. Four of these, Mts. Augustine, Iliamna, Redoubt and Spurr, are on Cook Inlet, and all of these but Iliamna have had significant eruptions in the past several decades.
In 1953, an eruption of Mt. Spurr deposited a layer of gritty dust on Anchorage, and all but put the city out of business. By the time that the 10th Air Division at Elmendorf Air Force Base decided to transfer operations to Ladd and Eielson near Fairbanks, all but four of the Division's F-94 interceptors had been grounded due to loss of power. The History of the Alaska Air Command states that the Division had lost its capability of basing an air defense mission at that time.
In 1976, an eruption of Augustine Volcano at the lower end of Cook Inlet also took its toll on air traffic. Two F-4E fighter were en route from Galena to Elmendorf when they flew through the abrasive ash at 31,000 feet. They were forced to turn back to Galena, where they landed safely despite the pilots' being unable to see forward through the sandblasted canopies. Three Japan Air Lines commercial flights en route from Anchorage to Tokyo were also affected, with very fine rough-colored material winding up in every nook and cranny of the aircraft.
The 1976 Augustine eruption destroyed the Geophysical Institute's research facilities on the island, but these have since been partially replaced. Signals from seismometers around the mountain are now being recorded at the Cook Inlet Volcano Observatory in Anchorage. The muted rumblings that are a part of the normal background of an active volcano continue, and it is only a matter of time before Augustine blows its top again. It is to be hoped that this time it may be possible to foretell the eruption in time for civil and military authorities to take at least a minimum of precautionary measures.
