Wednesday, November 21, 2012
Mount Doom Erupts!!
Tongariro National Park, in New Zealand, has three active volcanoes. It was the backdrop for many scenes in "The Lord of the Rings" movies. "Mount Doom" was shown spewing red hot lava and black smoke into a lowering sky. Today, a real volcanic eruption is happening there.
The eruption of Mount Tongariro, in Tongariro National Park, its second in less than four months, sent a dark ash plume about 1.9 miles into the sky. Authorities issued a no-fly alert above the mountain located in the sparsely populated area of central North Island.
If you’re worried about the Tongariro eruption adding to global warming, don’t worry -- volcanic eruptions can actually cool the earth, as none other than Benjamin Franklin noted in 1784. Volcanic eruptions create atmospheric haze, which decreases the amount of sunlight reaching the earth's surface and results in some cooling; the amount of the cooling depends on a number of factors, including the size of the eruption. Volcanoes can spew CO2 into the atmosphere, but the most unfortunate byproduct of their eruptions is Sulfur Dioxide SO2, which as it mixes with water vapor in the atmosphere, produces acid rain.
Volcanic eruptions in Iceland caused the cooling noted by Franklin in 1784, and Iceland’s Laki fissure system threw vast quantities of sulfur dioxide (SO2), hydrogen chloride (HCl), and hydrogen fluoride gases (HF) high into the atmosphere. The gases combined with water in the atmosphere to produce acid rain, destroying crops and killing livestock. The effects were most severe in Iceland; ultimately, more than 75 percent of Iceland’s livestock and 25 percent of its human population died from famine or the toxic impact of the Laki eruption clouds. The effects of the Laki eruptions were felt far beyond Iceland, as well. A 2008 Scientific American article provides details on the effects of volcanoes on climate.
Volcanic eruptions have been implicated in the so-called “great dying” that occurred 65 million years ago. The catastrophe that resulted in the extinction of the dinosaurs, among other things, coincided with one of Earth's largest continental flood basalt provinces, the Siberian Traps. In other words, a gigantic volcanic eruption launched enormous amounts of gases into the atmosphere, compromising global ocean chemistry, causing climate change and, possibly, the destruction of the ozone layer, which would explain the land extinction.
Although volcanic eruptions do produce CO2, the amount created is nothing compared to what humans are producing each year, which is about 10,000 times the amount created by volcanoes.