Volcanoes are Natural Polluters

Volcanic Emissions Include Gases and Aerosols

Aug 26, 2008 Alexandra Matiella Novak

Volcanoes have the ability to change Earth's atmosphere. Current eruptions are causing respiratory hazards and past eruptions have caused climate change.

The recent increase in activity of Kilauea Volcano in Hawaii has caused massive amounts of sulfur dioxide emissions. These emissions have reminded residents of the Big Island that volcanic gases can be hazardous to health and can cause respiratory problems. Moreover, large volcanic eruptions can emit enough ash to block out the sun and enough green house gases to cause atmospheric warming.

Volcanic Smog

For centuries, scientists have recognized a volcano’s ability to output enough gas and volcanic ash to cause them to be among the major polluters of the planet. Vog, a form of smog caused by volcanic output of sulfur dioxide and aerosols, pollutes the atmosphere and can cause respiratory problems for humans and animals living near volcanoes. Kilauea Volcano is a major source of vog on the island of Hawaii and on some days the vog is so bad that city officials warn people to stay indoors.

For most of Kilauea’s current eruption, the amount of sulfur dioxide released has been about 1,500 to 2,000 tonnes per day. However, since late spring of 2008, those emissions have increased to about 2,000 to 4,000 tonnes per day, sometimes spiking to 5,000 tonnes per day, according to the Hawaiian Volcano Observatory. When the sulfur dioxide is released into the atmosphere, mixing with water and chemical reactions with sunlight cause it to become a thick, hazy fog. Although this increase in activity is exciting for the volcanologists who study this volcano, it is causing respiratory illnesses, such as asthma, in those who live near the volcano.

Volcanoes and Climate Change

Major volcanic eruptions have been known to change the climate of the planet. Geological records of large ash falls from pre-historic and historic eruptions can be tied to instances of abrupt declines in the human population. For example, approximately 71,000 years ago, Mount Toba in Sumatra erupted enough ash into the atmosphere that layers of this ash are still present in the geologic record today.

But more interesting than that, there was another major event that happened about 70,000 years ago. In an article published in the Journal of Human Evolution in 1998, anthropologist Stanley Ambrose suggested that at this time the human population experienced a “bottleneck” in the evolution of modern humans. A "bottleneck" is an abrupt decrease in population, followed by rapid genetic divergence of the surviving populations. The title of Ambrose's article is "Late Pleistocene human population bottlenecks, volcanic winter, and the differentiation of modern humans." In his article, Ambrose speculates that the eruption of Toba caused a “volcanic winter” when the high amounts of ash in the atmosphere blocked out the sun. The decrease in the sun's energy that reached the Earth caused horrific devastation to human populations as well as the animals and plants they depended on for food.

Source:

Hawaiian Volcano Observatory’s Volcanic Hazards Page

Michigan Technological University's Volcano Clouds Page

The copyright of the article Volcanoes are Natural Polluters in Geology/Ecology is owned by Alexandra Matiella Novak. Permission to republish Volcanoes are Natural Polluters in print or online must be granted by the author in writing.

Kilauea Caldera Shrouded in Vog

Kilauea Caldera on a Clear Day

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