Volcanoes

volcanoes

Tracking volcanic ash: Helping airplanes avoid catastrophe

For more than 9,000 years, Chaitén volcano quietly towered 1,122 meters over southern Chile. The volcano seemed almost asleep: Its wide crater, shaped by layers of ash and pumice from an ancient eruption, held two lakes and a giant dome of obsidian — the same glossy black rock that was used in prehistoric times to shape artifacts found at archaeological sites as far as 400 kilometers away. Almost at the foot of the volcano, just 10 kilometers to the southwest, a small village grew into the town of Chaitén, population 4,200.

15 Apr 2010

Pacific Northwest earthquake threat heightened?

At any given time, a massive earthquake could strike the coast of the northwestern United States and southwestern Canada, the site of the Cascadia Subduction Zone. Scientists have long known about the potential earthquake threat to major population centers like Portland, Ore., Seattle, Wash., and Vancouver, British Columbia. But scientists thought that the likely place for such a quake was off the coast.

05 Mar 2010

Glaciers, not eruption: False alarm volcano mystery solved

When deep, long-period earthquakes started shaking the area around the Katla volcano on the southern tip of Iceland in 2001, officials feared it was a sign of an imminent eruption, as such quakes can be. So they were surprised when nothing happened. A new study identifies the source of the spurious signals: collapsing glaciers around the volcano, not the volcano itself. The finding may help researchers more accurately monitor other glacier-covered volcanoes.

07 Oct 2009

The trailblazers

Volcanologists have long been assessing the impacts of volcanic ash and gases on the environment and human health. This effort began in earnest when volcanologists at the U.S. Geological Survey undertook extensive studies of the environmental characteristics of ash from the 1980 Mount St. Helens eruptions. These studies included water leach tests showing that rain falling onto fresh ash can be quite acidic due to the liberation of acidic gas species that condense onto ash particles in the eruption cloud.

01 Oct 2009

Report from Ground Zero

How geoscientists aid in the aftermath of environmental disasters

01 Oct 2009

Storms brewing over volcanoes

Two hundred years ago, a sea captain was sailing in the Azores, a Portuguese archipelago in the middle of the Atlantic Ocean, when he observed “an immense body of smoke rising from the sea.” As he watched, the smoke, from a volcanic vent offshore of the island of St. Michael’s, began to rotate on the water “like a horizontal wheel,” the captain wrote in his 1811 account of the event. The rotating smoke and ash grew into a dark column and ascended high into the sky, spawning waterspouts and flashes of lightning.

09 Apr 2009

Scientists assess Redoubt's fury

After a series of five explosive eruptions from Sunday night through Monday morning, Alaska's Redoubt volcano quieted for about 15 hours Monday afternoon — long enough for scientists from the U.S. Geological Survey's Alaska Volcano Observatory to travel to the volcano to make observations and repair equipment (including the Redoubt webcam). A sixth explosive eruption followed Monday night at about 7:40 p.m.

24 Mar 2009

Alaska's Mt. Redoubt erupts at last

Blogging on EARTH

After months of threatening and rumbling, Mount Redoubt finally erupted late Sunday night.

Redoubt began to exhibit increasing unrest last fall, with seismic activity becoming markedly increased in January, and expectations of an imminent eruption were growing. On March 15, researchers detected four hours of continuous volcanic tremor and observed of a brief plume of gas and ash, according to the U.S. Geological Survey's Alaska Volcano Observatory.

23 Mar 2009

Undersea volcano erupts near Tonga

Blogging on EARTH

One of Tonga's submarine volcanoes is awake again, sending spectacular plumes of smoke, ash and steam high into the sky. MSNBC has video here.

19 Mar 2009

Pages