The activity of Poas includes mostly sulfur gas emissions and eruptions of muddy water and steam, which give it the reputation as the world's largest geyser. Volcan Irazu National Park contains Irazu Volcano, the tallest volcano in Costa Rica. This volcano erupted in 1963 and spewed ashes for two years. This forced people in nearby towns to sweep their roofs and sidewalks everyday during this period and caused great crop damage. Now that we've looked at the scary side of volcanoes let's also consider some benefits.
Pumice is derived from cooled lava and is used as polishing and grinding stones.
Sulfur can be obtained from deposits and used in chemical production. Volcanic ash also helps to improve soil fertility. The immense heat generated by volcanoes can also be put to use. Geothermal energy has been used to heat homes and to produce electric power. Bibliography Cashman, K.V. 2001.