Science / Medicine : Ozone Layer’s Volcanic Peril

Big volcanic eruptions thrust such large volumes of ozone-eating compounds into the atmosphere that they may pose an additional threat to Earth’s diminishing ozone layer, scientists said last week.

New evidence suggests that 12 million tons of hydrochloric acid and 6 million tons of hydrofluoric acid are produced annually by volcanoes. In big eruptions, such as the violent explosion of Alaska’s St. Augustine two years ago, or Washington’s Mt. St. Helens eight years ago, these ozone-damaging acids are shot directly into the upper atmosphere.

While the scientists were unable to study the direct effects of an erupting volcano, they were able to simulate the conditions in a computer program called SOLVGAS, which examined simulated emissions consisting of approximately 40 fluorine and chlorine compounds, according to their report in the journal Nature.

“This is not the only factor and certainly not the major factor” of ozone destruction, said University of Oregon geochemist Mark Reed.