Volcanoes: In The News
The article below is taken from Discovery.com
Toxic Gases Caused World’s Worst Extinction
Michael Reilly, Discovery NewsFeb. 4, 2009 — An ancient killer is hiding in the remote forests of Siberia. Walled off from western eyes during the Soviet era and forgotten among the endless expanse of wilderness, scientists are starting to uncover the remnants of a supervolcano that rained Hell on Earth 250 million years ago and killed 90 percent of all life.
Researchers have known about the volcano — the Siberian Traps, for years. And they’ve speculated that the volcanic rocks, which cover an area about the size of Alaska, played a role in runaway global warming that led to the end — Permian mass extinction, the worst dying the planet has ever seen.
Now a team of researchers led by Henrik Svenson of the University of Oslo in Norway have performed a series of experiments, showing the volcano employed an arsenal of deadly weapons during its 200,000-year-long assault on the biosphere.
Prime among them was carbon. Searing magmas from the volcano intruded into the Tunguska Basin in eastern Siberia, a region laden with thick deposits of coal, oil and gas. Heat from the molten rock baked the hydrocarbons, turning the area into the world’s largest fossil fuel-burning plant. In all, the volcano may have belched as much as 100,000 gigatons of carbon into the air (all of humanity emits about eight gigatons of carbon annually).
That’s more than enough to cause a global climate apocalypse. But the team also wanted to know what happened when lava infiltrated the area’s abundant salt deposits. When heated in a laboratory to 275 degrees Centigrade (527 degrees Fahrenheit), the salts released a host of toxic gases, chief among them methyl chloride, an efficient ozone-killer.
“This is the first geologically realistic evidence that ozone collapse during the end-Permian could have actually happened,” Svenson said.
But there is still a lot of uncertainty surrounding the findings, Linda Elkins-Tanton of the Massachusetts Institute of Technology said.
“There is evidence of a large number of genetic mutations in the fossil record around this time,” she said, which could be the result of an onslaught of ultraviolet radiation due to a weak ozone layer. “But the idea of ozone destroyers is pretty new. The question is whether or not the eruptions were powerful enough to inject gases into the stratosphere.”
The answer may come from close examination of hundreds of pipe-like structures strewn throughout the Tunguska Basin. Often 300 meters (984 feet) in diameter, Svenson’s team believes the pipes are ancient volcanic craters left over after the lethal mix of carbon and chlorine gases exploded into the atmosphere.
The article below is taken from The LA Times
Mt. Redoubt volcano’s ‘unrest’ recalls 1989 eruption
Pete Thomas, LA TimesFebruary 3, 2009 — The latest from the Alaska Volcano Observatory on the status of Mt. Redoubt: “Unrest at Redoubt Volcano continues. Seismic activity remains elevated above background.”
Sounds like a broken record, but at least Mt. Redoubt is providing ample warning and has all of Alaska on alert.
Longtime residents surely recall a five-month stretch that began in late 1989 during which the 10,197-foot volcano provided a string of eruptions and a steady outpouring of smoke and ash.
A United Press International article that Dec. 15 featured this initial announcement: “Redoubt Volcano southwest of Anchorage shook with thousands of small earthquakes Thursday, then erupted and shot a cloud of ash seven miles high.”
Farther down in the story: “The eruption followed 24 hours of constant warning tremors, which calmed down after the eruption ended, then picked up again…. The ash plume — which shot 35,000 feet above the two-mile-high mountain — was carried toward Anchorage by strong winds… But the ash cloud skirted Anchorage and dusted towns beyond the city.”
A day after a second, more violent eruption occurred that Dec. 17, the Associated Press reported: “Haze from the volcano drifted over Anchorage, Alaska’s largest city with more than 200,000 people. The debris caused power outages, disrupted air travel and triggered public-health warnings.”
But it was Christmas week and the economy was not in shambles. Shoppers, according to the report, filled “the streets and malls over the weekend.”
Tags: Case Studies, Climate Change, Earth Science, Volcanoes
Posted in Earth Science, Volcanoes
