EPOW Ecology Picture of the Week -- Volcanic Field on the Rim of Fire

Explanation: Few Americans likely realize that there are spectacular volcanic landscapes in coastal southeast Alaska. Here is the amazing volcanic field of Crater Ridge and dormant Mt. Edgecumbe on Kruzof Island, west of the town of Sitka and south of Juneau.

The scenic Edgecumbe Volcanic Field resulted from prehistoric eruptions that were last only slightly reawakened with two minor tephra-forming eructations some four and six thousand years ago, following a larger blast nearly ten thousand years ago.

The spectacle of Crater Ridge is best appreciated from the air
where its massive lava fields can be seen.

Mt. Edgecumbe is classified as a stratovolcano, which typically has
a cone built of alternating flows of andesitic lava and pyroclastic flows.
Stratovolcanoes, such as this one, tend to be immense and very steep,
although Mt. Edgecumbe can be climbed in a day's hike from base camp.

This volcanic landscape lies on the North American Plate near the Queen Charlotte-Fairweather transform fault, and is part of the so-called "Ring of Fire" defined by volcanoes, fault lines, and edges of tectonic plates that nearly circle the entire Pacific Ocean.

The ecological implications of volcanoes and volcanic landscapes in southeast Alaska are wide-ranging.

They have produced fertile soils in which grow dense, true temperate rainforests of cedar and hemlock.

They have created topographic relief (view topography map of the region) -- mountains, ridges, cliffs -- on which ice fields and glaciers have formed and carved out valleys rich with habitats for much wildlife.

Along the margins of such volcanic islands skulk wolves in winter, using shorelines as key passageways in search of Sitka black-tailed deer as prey.

Extra: Apparently, in 1974 a prankster alighted hundreds of tires in the crater of Mt. Edgecumbe in a hoax to make locals think that the volcano was once again erupting.

EPOW - Ecology Picture of the Week