Volcanic Eruptions: Impacts on Climate and Aviation
Did you know the United States has over 160 active volcanoes, ranking among the highest number in the world? During the last 32 years, 107 eruptions were reported at 32 volcanoes in the United States. There are three main regions of volcanic activity in the United States: Alaska, the Cascades Range (southern British Columbia to northern California) and Hawaii. Currently, there are eleven alerts for active volcanoes in the United States. There are live webcams at some volcanoes.
Volcanic eruptions produce magmatic material (stones or ash) and gases, such as carbon dioxide and sulfur. Volcanic eruptions have important effects:
- Sulfur aerosols reflect sunlight back to space, lowering temperatures. Large eruptions like Mount Pinatubo (1991) can impact global temperature. Pinatubo released a 20 million ton sulfur dioxide cloud into the stratosphere – the largest since satellite observation began – that cooled the Earth’s surface over three years by as much 1.3 degrees Fahrenheit!
- Volcanic ash impacts daylight and temperature in nearby areas. When Mount St. Helens erupted it was so dark that streetlights were on during the middle of the day and the air temperature remained at 59 degrees Fahrenheit for 15 straight hours.
- Volcanic gases destroy the ozone layer, increasing ultraviolet radiation on our planet.
Volcanic eruptions also impact industries such as aviation. In 2010, Iceland’s Eyjafjallajökull volcano caused the biggest closure of European airspace since World War II, adding up to a loss of 2.6 billion dollars. Eruptions form ash clouds difficult to distinguish from regular clouds by air traffic control and aircraft weather radars. Volcanic ash reduces visibility, damages flight control systems, causes jet engines to fail and accelerates wear on aircraft components. Volcanic ash travels long distances and can circle the globe in a matter of weeks.
Graphic: USGS Volcano Hazards Program – U.S. Volcanoes and Current Activity Alerts
(Source: Diefenbach, A. “Re: Volcanic activity and eruptions 1980-2012”. Message to the author. 30 July 2013. Email. and Robock, A. 2000. Volcanic Eruptions and Climate. Reviews of Geophysics 38(2):191-219 and Textor, C., H. Graf, C. Timmreck, and A. Robock. “Emissions from Volcanoes” Emissions of Chemical Compounds and Aerosols in the Atmosphere. Granier, C., C. Reeves, and P. Artaxo. 2003. 7-32. and United States Geological Survey. 2010. Airborne Volcanic Ash-A Global Threat to Aviation. Accessed online 30 July 2013. http://pubs.usgs.gov/fs/2010/3116/fs2010-3116.pdf and Oxford Economics. The Economic Impacts of Air Travel Restrictions Due to Volcanic Ash. Accessed online 30 July 2013. http://www.airbus.com/company/environment/documentation/?docID=10262&eID=dam_frontend_push and Mother Nature Network. 2010. Which U.S. Volcanoes are Likely to Erupt Next. Accessed online 31 July 2013. http://www.mnn.com/earth-matters/translating-uncle-sam/stories/which-us-volcanoes-are-likely-to-erupt-next and United States Geological Survey.)