Turrialba's Summit. Photo by Federico Chavarria Kopper, 1999.
Turrialba's Summit. Photo by Federico Chavarria Kopper, 1999.

The volcano Turrialba, is a heavily vegetated stratovolcano located in the province of Cartago, Costa Rica that has been intermittently active for several hundred years. The volcano has a barren summit region which rests 3,340 meter high. The Turrialba national park, where the volcano is located, is the least visited volcano from the seven Costa Rican volcanoes and is the the eastern most volcano of all seven. The Volcanoes are believed to have been formed by the Cocos plate sub-ducting into the Caribbean plate. Not far off from the Costa Rican coast lies a triple junction of the Cocos, Caribbean and Nazca plate. The volcano's summit consists of three craters that display varying amounts of volcanic activity. One of these craters has fumaroles, which release toxic gas such as carbon dioxide and sulfur dioxide into the atmosphere. The volcano's summit consists of three main craters that display varying amounts of volcanic activity. One of these craters has fumaroles, which releases toxic gas such as carbon dioxide and sulfur dioxide into the atmosphere. The volcano's viscosity has been predominately moderate to high, releasing pyroclastic flows and ash into the air. The viscosity of the volcano can be classified by its medium to high silica content and andesitic magma.

The last major eruption that occurred in 1866, covered most of Costa Rica and even parts of Nicaragua in ash. The late 1990's, many scientists began seeing an increase in seismic activity, signifying a restart of volcanic activity. In 2001, the volca
Dying pastures due to toxic gas released by Turrialba. Photo by Carlos Gonzalez
Dying pastures due to toxic gas released by Turrialba. Photo by Carlos Gonzalez
no began showing signs of volcanic activity and in 2007, activity began intensifying, and since 2007 frequent acid rain showers caused by the activity killed or damaged much of the vegetation to the southwest of the summit leaving the are brown and orange. In April 2008, the volcano began releasing very large amounts of sulfuric gases prompting authorities to issue a temporary closure of the national park. The release of toxic gases also affected the local flora and fauna, causing massive damage to plants. According Eliécer Duarte, a local scientist, the chance of the vegetation growing back was very slim to none. The effect on wildlife has also been apparent as animals cannot live in such an environment. The release of sulfuric gases has also caused acid rain, bringing forth even more damage to surrounding homes and vegetation. Local workers from a milk factory have experienced difficulty breathing from inhaling the sulfuric air and have resorted to gas masks to allow them to continue working. The economic impact is also evident, as milk production has decreased since the gases became stronger. In September of 2009, the towns of La Picada and La Silva, neighboring cities of the volcano, left their homes in fears that the Volcano would erupt violently.

On January 4th, 2010 the Costa Rican National Seismological Network recorded strong, long lasting volcanic tremors that were accompanied by gas plumes over the volcano and on January 6th, 2010, the volc
Area affected (dark grey spot) by the Eruption. Caption red caption reads "40 people evacuated late afternoon." Map provided by Nacion.com
Area affected (dark grey spot) by the Eruption. Caption red caption reads "40 people evacuated late afternoon." Map provided by Nacion.com
ano erupted, emitting ash and small amounts of pyroclastic flow around a 20 kilometer radius of the volcano. 40 people in the surrounding towns of El Centro and El Retiro were evacuated and taken to nearby shelters in Santa Cruz and La Pastora. Police authorities stayed behind to guard the residences to prevent looting and theft. All this is necessary since the volcano eruption signs are all there. The signs of volcanic activity are increasing and intensifying I think the evacuations are a must. The release of the toxic gases are beginning to affect the vegetation and soon would soon be effecting the people who live there as well. According to a local red cross worker, the falling soot or ash had a very strong sulfuric odor and became dark when it came in contact with the rain. Eliécer Duarte from the Volcanic and Seismology Observatory Experts from Costa Rica, states that this eruption is something new and indicates a change in activity in the interior of the volcano. As of now, activity still continues, though it is uncertain whether the volcano will see another eruption any time soon.



Sources

1. Unrest at Turrialba Volcano. January 28, 2010. http://earthobservatory.nasa.gov/IOTD/view.php?id=42425
2. Costa Rica: Eruption at Turrialba. January 6, 2010. http://volcanism.wordpress.com/2010/01/06/costa-rica-eruption-at-turrialba/
3. Turrialba Eruption leads to Evacuation. January 6, 2010. http://wvw.nacion.com/ln_ee/2010/enero/06/sucesos2215602.html
4. Turrialba's Unwelcome Emissions. April 26, 2009. http://volcanism.wordpress.com/2009/04/26/turrialbas-unwelcome-emissions/
5. Damage caused by Turrialba win ground this year. April 26, 2009. http://wvw.nacion.com/ln_ee/2009/abril/26/sucesos1944410.html
6. Global Volcanism Program. Smithsonian Museum of Natural History. http://volcano.si.edu/world/volcano.cfm?vnum=1405-07=
7. RSN Preliminary Report on Turrialba Volcano, Costa Rica. January 4-10, 2010. http://www.rsn.geologia.ucr.ac.cr/Vulcanologia/Informes%20volcan%20Turrialba/Turrialba%20volcano-informe07012010.pdf
8. Subduction Zone structure and magmatic processes beneath Costa Rica constrained by local earthquake tomography and petrological modeling. S. Husen, R. Quintero, E. Kissling and B. Hacker. February 26, 2003.http://www.geol.ucsb.edu/faculty/hacker/viz/Husen03_Costa_Rica_subduction_zone.pdf