That is in addition to the presumed eruption early Thursday that residents reported.
The volcano is in Parque Nacional Rincón de la Vieja about 25 kilometers or about 15.5 miles northeast of Liberia in Guanacaste. The area is sparely populated.
As a result of an inspection Thursday the national emergency commission is urging park officials to restrict tourist access to the upper part of the mountain and adopt more security measures.
The Comisión Nacional de Prevención de Riesgos y Atención de Emergencias noted that Rincón de la Vieja is one of five active volcanoes in the country. Last October, after a larger eruption that dumped ash into a local river, the commission increased surveillance of the mountain and urged park rangers to get better radios. The volcano has been producing small eruptions for 40 years.
Scientists from the Red Sismológica Nacional of the Universidad de Costa Rica conducted the survey of the volcano Thursday.
The commission also suggested that those persons living near the volcano should take precautionary measures.