The Poas Volcano early Sunday awoke residents of the province of Alajuela with a strong rumble.
At about 1 a.m., the volcano’s crater ejected mud and ash more than 500 meters into the air. Ashes traveled hundreds of meters around the national park, rangers reported.
Although the volcano is frequently active, this kind of strong explosion has not been recorded since 2006. Experts said the activity was normal, but they will continue monitoring the volcano.
Poás Volcano National Park will remain open to tourists while experts determine if there is any risk to visitors.