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Costa Rica

Costa Rica’s active volcanoes are young—formed within the last two mil- lion years—such as Arenal, Poás, Irazú, and Turrialba. Arenal stands alone on the plain, a classic cone against the sky. Poás’s main crater is more than a mile across and 1,000 feet deep with an acid lake in its center. Irazú’s peak looks like the surface of the moon—rocky and life- less. Turrialba, which resembles Irazú, is a wilderness. Costa Rica also experiences earth tremors and small earthquakes occasionally. During one two-month peri- od in 1989, seismologists recorded more than 16,000 tremors in Costa Rica. Most, however, were not felt by anyone. The reason for the tremors and quakes is that Costa Rica lies at the place where the Pacific’s Cocos Plate—a piece of the earth’s crust some 3,188 miles (510 km) wide—meets another plate under the

Along Costa Rica’s east coast, there are thick tropical rainforests. These jungle regions provide homes for hundreds of dif- ferent species of animals.

Caribbean. The two are rubbing, jostling and shoving each other as the Cocos Plate moves east at a rate of about four inches a year. The last major quake hit on November 20, 2004, measuring 6.4 on the Richter scale .