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Turrialba Volcano is an active volcano (October 2015) in central Costa Rica. Visitors used to be able to hike down into the main crater, but increased volcanic activity in 2014-15 has caused the surrounding Turrialba Volcano National Park to close. The stratovolcano is high and is about 45 minutes from the Atlantic slope town of Turrialba. The summit has three craters, the largest of which has a diameter of .〔(【引用サイトリンク】first=Adam )〕 Below the summit is a mountain range and montane forest, with ferns, bromeliads, lichens and mosses. Most of the forest is either primary or secondary forest.〔(【引用サイトリンク】first=Adam )〕 Turrialba is adjacent to Irazú and both are among Costa Rica's largest volcanoes. Turrialba has had at least five large explosive eruptions in last 3500 years. On clear days both the Pacific Ocean and Caribbean Sea can be seen from the summit. The volcano is named after its canton, Turrialba, in Costa Rica's Cartago Province. There is no clear consensus on the origin of the name Turrialba, but historians disagree with attempts to attribute the name to the patronym Torrealba (from Aragon in Spain) or from the Latin ''Turris alba'' (white tower). The general consensus is that Turrialba derives from the local Indian (Huetar language), but there is no agreement on its actual roots. ==Activity== * During the 19th century, the volcano erupted and emitted ash several times (1847, 1853, 1855, 1859, 1866), producing pyroclastic flows. The last major eruption was in 1866. * Small signs of activity start in 1996. * In January 2001, the volcano reported increased activity, displaying strong fumarole activity at the central craters. The volcanic activities have increased since 2005. * On March 31, 2007, the volcano started to show some activity with ash eruptions. * The National Park area opened for visitors was closed from 2009 to 2011. * On January 8, 2010, a phreatic eruption occurred, creating a new opening near the crater on the southwest, and the temperature increased from . Two villages, La Central and El Retiro, were evacuated. * On January, 2012 a new opening on the west of the crater was created after a phreatic eruption. * On April 12, 2012, a small eruption occurred. * On May 21, 2013, at 08:52, a gas explosion widened several openings near the main crater that appeared in 2010 and 2012. * In July 2013 researchers found that tremors around the area increased from about twenty earthquakes a day, to up to thirty per hour. * On October 17, 2014, the quantity of tremors increased from around 50-100 a day, to 200 a day. * On October 29, 2014, at around 10:10, a tremor started and kept constant, until a phreatic eruption occurred around 23:10 at the west opening that appeared in January 2012. This eruption sent a large amount of volcanic material to areas up to away. Many citizens reported ash falling on their properties and a strong odor of sulphur in the cantons of Vásquez de Coronado, Goicoechea, Moravia, Desamparados, Aserrí, Escazú, Santa Ana, Montes de Oca, Tibás, Alajuelita, Puriscal, San José in the province of San José, La Union in the province of Cartago and Santo Domingo and Heredia, in the province of Heredia.〔(【引用サイトリンク】title=Volcán Turrialba hace erupción y provoca intensa caída de ceniza en los alrededores )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Turrialba Volcano」の詳細全文を読む スポンサード リンク
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