Wednesday, August 08, 2007
Ring of Fire
Across Cook Inlet from the Kenai Peninsula, six volcanoes stand in a line running north to south. Spurr, Redoubt, and Iliamna are visible on the western horizon towering above their lower neighbors that make up the rest of the Alaska Range. Augustine and sometimes Douglas can be seen from the southern coastline of the peninsula.
The Kenai Peninsula sits on the northern edge of the Pacific Plate, which is crashing into the North American Plate, and being forced underneath it; a process called subduction. The leading edge of our plate melts in the heat of the magma and pressure builds up. This pressure is relieved through all of these volcanoes.
This area is also criss-crossed with fault lines whose minor shakes remind us of how brief our stay here on earth is compared to the vast amount of shaking it has taken to lift up all these mountains and then erode them back down again.
There are a bunch more volcanoes extending south and west down the Aleutian Island chain. Most of these remain active, with periodic eruptions. Augustine, Iliamna, Redoubt and Spurr have all erupted in the past 30 years, with the Augustine and Redoubt eruptions providing the most drama and ash for us.
Augustine is perhaps the most active; with minor eruptions a year or so ago. This one is scary, since it is an island out in Cook Inlet. The northeast wall of the volcano is supposedly unstable. A major blow could cause that wall to come crashing down into the Inlet creating a tidal wave that would travel all the way up Kachemak Bay and up Cook Inlet. Most of our low-lying communities would be wiped out in an instant.
But when they're quiet, they're spectacular!
So, here is what I see on the western horizon, across Cook Inlet (on clear days.)