The Poás Volcano, is an active 2,697-metre (8,848 ft) stratovolcano in central Costa Rica and is located within Poas Volcano National Park. It has erupted 40 times since 1828, including April 2017 when visitors and residents were evacuated. The volcano and surrounding park were closed for nearly 17 months, with a 2.5 kilometer safety perimeter established around the erupting crater. On September 1, 2018, the park reopened with limited access only to the crater observation area and required a reservation to be made on the National Park Website. Adjacent trails to Lake Botos as well as the museum at the visitor center remained closed. The volcano erupted briefly twice in September 2019.
Poás volcano crater, shown before the 2017 eruptions
Space view showing the destroyed vegetation zone by hot and acid gases
Column of smoke rising from the main crater
Lake Botos is an inactive crater within Poás Volcano National Park
Acid rain is rain or any other form of precipitation that is unusually acidic, meaning that it has elevated levels of hydrogen ions. Most water, including drinking water, has a neutral pH that exists between 6.5 and 8.5, but acid rain has a pH level lower than this and ranges from 4–5 on average. The more acidic the acid rain is, the lower its pH is. Acid rain can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids.
Acid rain
Acid clouds can grow on SO2 emissions from refineries, as seen here in Curaçao.
Since 1998, Harvard University wraps some of the bronze and marble statues on its campus, such as this "Chinese stele", with waterproof covers every winter, in order to protect them from corrosion caused by acid rain and acid snow
The coal-fired Gavin Power Plant in Cheshire, Ohio
