ANCHORAGE (AP).- Even a century after one of the world's largest volcanic eruptions, a strong wind still whips up the ash that rained down on what became known as Alaska's Valley of Ten Thousand Smokes. Pumice chunks still dot the beaches of Kodiak Island across Shelikof Strait.

The three-day explosion that began June 6, 1912, spewed ash as high as 100,000 feet above the sparsely populated Katmai region, covering the remote valley to depths up to 700 feet. The volcanic cloud spread across the United States and traveled as far as Algeria in northern Africa in the most powerful eruption of the 20th century and one of the five largest in recorded history.

"Every minute we are awaiting death," John Orloff wrote to his wife from Kaflia Bay, 30 miles east of the explosion.

Remarkably, there were no eruption-related deaths, although the ash-filled air was believed to be a contributing factor in the death of an elderly Kodiak-area woman who had health problems that included tuberculosis.

The eruption killed an untold numbers of animals and plants and decimated salmon populations in the region until they began recovering in the 1920s.

An estimated three cubic miles of magma and debris beneath Mount Katmai exploded through the vent of Novarupta six miles to the west, an event that today could ground planes across a wide swath of the globe. The magma drainage caused Katmai's summit to collapse, creating an oblong caldera 2 ½ miles across and filling a lake more than 800 feet deep.

Scientists still don't completely understand the unique plumbing system involving the two separate volcanos, why magma moved laterally from its storage reservoir to create a new vent instead of exploding through Mount Katmai's existing vent, said U.S. Geological Survey geologist Tina Neal, who is based at the Alaska Volcano Observatory in Anchorage.

Novarupta, Latin for new eruption, had 45 times the magma volume that erupted in the 1980 Mount St. Helens explosion in Washington state and has supplied a wealth of research material and better understanding of how explosive volcanos work. But there is plenty still to learn, scientists say.

"It was such an enormous geological event and represents one of the most dynamic processes of our earth," Neal said. "It also was just a tremendous opportunity for science to move forward in the area of volcanology."

To mark the centennial anniversary of Novarupta, events are planned around Alaska throughout the year. Lectures are scheduled. A field trip to the moonlike valley is planned for high-school students whose ancestors had to abandon villages in the region located at Katmai National Park and Preserve. The Alaska Historical Society sponsored a centennial poster contest among elementary school students, with the theme, "Novarupta: A Volcano that Made History!"

The 11-year-old contest winner, Nicole Smith, lives in the tiny community of Port Alsworth, 130 miles north of Novarupta. Her teacher told her about the volcano, so Smith decided to write about it and to draw pictures, including her entry — a girl around her age looking out of a hut as a volcano in the background oozes a red stream. She also did some research and liked what she learned about the massive explosion.

"I thought it was cool," she said. She won $100 for her winning entry.

In the days leading to the volcanic outburst, earthquakes were felt around the region, according to a new USGS report by Wes Hildreth and Judy Fiersten, who have done extensive research on the pre-statehood eruption. The first plume was seen at 1 p.m. on June 6, the same time a great explosion and earthquake were reported from what is now Puale Bay, 40 miles to the south. An explosion two hours later was heard from as far away as Juneau, nearly 750 miles away.

Light ash began falling 100 miles from Novarupta at what is now the city of Kodiak, but was then a village of about 400 people. The ash cloud became thicker and thicker until it looked like night long before sunset. Altogether, three explosive episodes spanned across 60 hours.

"One cannot see daylight. In a word it is horrible," Orloff wrote from Kaflia Bay, where he likely was fishing. He and others were ultimately rescued by a steamship crew, but his letter echoes the desperation many felt, telling his wife the ashes were 10 feet deep in places.

"We have no water," Orloff wrote in the correspondence, provided by the Kodiak-based Baranov Museum. "All the rivers are covered with ashes. Just ashes mixed with water."

The museum's curator of collections, Anjuli Grantham, said another man was alone at his cabin on Shelikof Strait. When the man awoke, he thought he had died and gone to hell, a belief he held for three days. The cascade of ash stung his eyes and the water tasted like sulfur.

"It wasn't until he was saved and recognized some of the people around him that he realized, it was like, 'Oh, I'm alive,'" Grantham said. "It was that surreal."

The volcanos in the region are still active, but none show any signs of imminent explosions, Neal said. They are among numerous volcanos in Alaska monitored by the volcano observatory with increasingly sophisticated instruments developed over the last century that enable early warnings of pending eruptions. Volcanology was in its infancy in the early 20th century, when Alaska volcanos were not monitored or well known.

Another eruption in the future could have a similar magnitude, but with a far greater impact in today's more crowded, technological world, scientists say.

"Because of the exponential increase in air traffic in the North Pacific region during recent decades, greater potential hazards are posed by possible encounters between jet aircraft and drifting clouds of volcanic ash from explosive eruptions," senior USGS research volcanologist Robert Tilling wrote in a forward of the Novarupta report. "The future occurrence of another great explosive eruption in Alaska is not a question of if, but when, and we should be better prepared in such eventuality."


Copyright 2012 The Associated Press.