Costa Rica’s Rincón de la Vieja volcano erupted yesterday sending a plume approximately 1,000 meters (3,280 feet) above its crater and bringing the number of eruptions recorded since the weekend to 21. The latest eruption followed a Sunday event that sent volcanic mud and debris downstream and left residents in the Borinquen area reporting ash fall, according to the Volcanological and Seismological Observatory of Costa Rica (OVSICORI)
In its report yesterday, the observatory said it had counted 20 eruptions through 9 a.m. The most significant occurred Sunday, triggering a lahar, a flow of water, mud, rocks and volcanic debris. Rincón de la Vieja remained at OVSICORI’s activity level 3, or caution. Separately, the National Emergency Commission (CNE), maintained a green alert for nearby communities. The two designations come from different monitoring and emergency systems.
The green alert covers Dos Ríos and Aguas Claras in the Upala area, along with Mayorga, Cañas Dulces and Curubandé in Liberia. Authorities announced that alert on September 2 after an increase in eruptions, including events that pushed volcanic material into river channels north of the volcano.
For those living near or visiting the volcano, those river channels are a particular concern. Lahars can carry mud and rocks downstream, extending the danger beyond the crater. OVSICORI has urged people to avoid the summit and stay away from riverbeds near the volcano. Monitoring has focused on waterways that could carry this material, including the Pénjamo, Azul and Pizote rivers and the Azufrada stream.
The weekend’s eruptions follow weeks of elevated activity. Authorities recorded more than 100 eruptions during July and August. The CNE identified an August 31 eruption at 4:37 p.m. as the volcano’s most energetic event of the year at that point, with volcanic debris and mudflows raising concerns for communities downstream.





